1

Scientific Program

2

Abstracts

Oral Presentations

Monday February 13 2017

3

Plenary Lecture

Oxidized Cytosines as new Epigenetic Bases

Thomas Carell Center for Integrative Protein Science at the Department of Chemistry

Ludwig-Maximilians-University Munich Germany

Epigenetic information is stored in the form of modified bases in the genome The positions and the kind of the

base modifications determines the identity of the corresponding cell Setting and erasing of epigenetic imprints

controls the complete development process starting from an omnipotent stem cells and ending with an adult

specialized cell I am going to discuss the latest results related to the function and distribution of the epigenetic

marker bases 5-hydroxymethylcytosine (hmC) 5-formylcytosine (fC) 5-carboxycytosine (caC) and 5-

hydroxymethyluracil (Scheme 1)[1] These nucleobases control epigenetic programming of stem cells and some

of these bases are also detected at relatively high levels in brain tissues Synthetic routes to these new bases will

be discussed that enable today preparation of oligonucleotides containing the new bases The second part of the

lecture will cover mass spectroscopic approaches to decipher the biological functions of the new epigenetic

bases of which some were described in the past as pure DNA lesions[2] In particular results from quantitative

mass spectrometry new covalent-capture proteomics mass spectrometry and isotope tracing techniques will be

reported The data allow us to unravel the chemistry in stem cells and the protein networks that are controlled

by the epigenetic base modifications[3]

[1] M Wagner J Steinbacher T F Kraus S Michalakis B Hackner T Pfaffeneder A Perera M Muumlller A

Giese H A Kretzschmar T Carell Angew Chem Int Ed 2015 doi 101002anie201502722 Age-

Dependent Levels of 5-Methyl- 5-Hydroxymethyl- and 5-Formylcytosine in Human and Mouse Brain Tissues

[2] Perera D Eisen M Wagner S K Laube A F Kuumlnzel S Koch J Steinbacher E Schulze V Splith N

Mittermeier M Muumlller M Biel T Carell S Michalakis Cell Rep 2015 11 1-12 TET3 Is Recruited by

REST for Context-Specific Hydroxymethylation and Induction of Gene Expression

[3] CG Spruijt F Gnerlich AH Smits T Pfaffeneder PWTC Jansen C Bauer M Muumlnzel M Wagner

M Muumlller F Khan HC Eberl A Mensinga AB Brinkman K Lephikov U Muumlller J Walter R Boelens

H van Ingen H Leonhardt T Carelllowast M Vermeulenlowast Cell 2013 152 1146-59 Dynamic readers for 5-

(hydroxy)methylcytosine and its oxidized derivatives

4

Keynote Lecture

Chemiluminescence Probes with Color Modulation

Doron Shabat Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Chemiluminescence is among the most sensitive methods for achieving a high signal-to-noise ratio in various

chemical and biological applications We have developed a modular practical synthetic route for preparation of

turn-ON dioxetane-tethered fluorophore chemiluminescent probes The chemiluminescent emission of the

probes was significantly amplified through energy transfer mechanism under physiological conditions Two

probes were composed of dioxetane tethered with green and near-infrared (NIR) fluorescent dyes While both

probes were able to provide chemiluminescence in vivo images following subcutaneous injection only the NIR

probe could provide chemiluminescence image following intraperitoneal injection These are the first in vivo

images produced by dioxetane-chemiluminescence probes with no addition of surfactant enhancer We

anticipate that our practical synthetic methodology will be useful for preparation of various chemiluminescent

probes for numerous applications

5

Selenocysteine Chemistry and Total Chemical Synthesis Applied for Accessing

Human Selenoproteins

Norman Metanis Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Once considered a toxic element selenium is now known as an essential element for life For example in

humans it is incorporated in proteins known as selenoproteins containing the 21st encoded amino acid

selenocysteine (Sec) The differences between selenium and sulfur in their redox potentials pKas and

nucleophilicities and electrophilicities give selenium interesting chemistry For example Sec can be used as a

tool for chemical protein synthesis and allowing for site selective modifications It can be also incorporated

into protein sequences to enhance oxidative protein folding This lecture will discuss our recent studies on

chemical protein synthesis using Sec and selective deselenization reactions which convert Sec into Ala or Ser

These advances in chemical protein synthesis bring us closer to accessing naturally occurring selenoproteins

especially human selenoproteins that still await functional characterization

6

Olrsquo Bimane is Learning New Tricks

Flavio Grynszpan1 Partha J Das1 Ankana Roy1 Yael Diskin-Posner2 Iddo Pinkas2

Michael Firer3 Michael Montag1 1Chemical Sciences Ariel University Ariel Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemical Engineering and Biotechnology Ariel University Ariel Israel

Bimanes are hetero-bicyclic molecules that can be readily synthesized in moderate to good yields These low

molecular weight fluorophores were developed by Prof E Kosower and co-workers about 40 years ago[i]

From the two possible diastereomeric forms only syn-bimanes are strongly fluorescent Some bimane

derivatives have become useful as fluorescent probes for different applications ranging from biological labeling

to LASER dyes Recently we showed that when attached to an appropriate carrier moiety syn-bimane can

cross the blood-brain-barrier (BBB) of living mice and be clearly detected in brain tissue[ii] syn-Bimanes

present an N-imide structure as an integral part of their skeleton which in the past was never exploited as a

metal binding motif We showed that a cationic Pd(II) complex (2) containing syn-(MeMe)bimane (1 R1-4 =

Me) as a ligand could be prepared and was fully characterized[iii] We are currently involved in the preparation

of bimane derivatives where the oxygen atoms are replaced by sulfur atoms The novel mono- and di-thioxo-

bimanes are expected to display novel spectroscopic properties and give rise to more stable complexes with

different metals Our latest results with oxo- and thioxo-bimanes their structures chemistry and spectroscopic

studies will be presented

[i] E M Kosower B Pazhenchevsky E Hershkowitz J Am Chem Soc 1978 100 6516

[ii] I Lapidot D Baranes A Pinhasov G Gellerman A Albeck F Grynszpan S E Shatzmiller Med

Chem 2016 12 48

[iii] PJ Das Y Diskin-Posner M Firer M Montag F Grynszpan Dalton Trans 201645 17123-17131

7

Synthesis of Highly Functionalized Alkenylfluorides by Silver-Mediated

Fluorodestannation

Heiko Sommer12 Alois Fuumlrstner1 1Organometallic Chemistry Max-Planck-Institut fuumlr Kohlenforschung Muumllheim an der Ruhr

Germany 2Schulich Faculty of Chemistry Technion - Israel Institute of Technology Haifa Israel

The role of fluorine in synthetic and medicinal chemistry receives an ever-increasing attention as fluorine plays

a unique role in influencing the conformation solubility potency permeability or degradability of small

molecules The late-stage introduction of fluorine is of great interest as it allows the modification of complex

molecules without significantly changing the synthetic route

In conjunction with our previously reported ruthenium-catalyzed directed trans-hydrostannation of internal

alkynes[1] an efficient method for the synthesis of highly elaborate alkenyl fluorides could be implemented

(Scheme 1)[2]

Scheme 1 Hydrostannationfluorodestannation for the synthesis of fluoroolefins

During our studies we developed a mild protocol that allowed us to transform a plethora of alkenylstannanes

into the corresponding fluorides while overcoming competing protodestannation[3] Key to success is the

utilization of the non-hygroscopic salt silver(I) diphenyl phosphinate (AgDPP) as a mediator

We applied this new protocol to the synthesis of highly functionalized biologically relevant compounds

consisting among others of a polyketide derivative a peptide bioisoster and a prostaglandin derivative (Scheme

2)

Scheme 2 Selected examples of the silver-mediated fluorodestannation

Literature

[1] a) S M Rummelt A Fuumlrstner Angew Chem Int Ed 2014 53 3626-3630 b) S M Rummelt K

Radkowski D-A Roşca A Fuumlrstner J Am Chem Soc 2015 137 5506-5519

[2] H Sommer A Fuumlrstner submitted manuscript 2016

[3] M A Tius J K Kawakami Tetrahedron 1995 51 3997-4010

8

Stimuli-responsive Self-immolative Chemiluminescent Polymers

Samer Gnaim Doron Shabat

Organic Chemistry Tel Aviv University Tel Aviv Israel

Molecular probes based on 3-hydroxyphenyl-12-dioxetane chemiluminescence light emission are widely used

for various sensing and diagnostic applications (eg DNA enzymatic and chemical probes) Amplification of

molecular signals is an important task for the development of sensitive diagnostic probes in the field of

chemical sensing Recently various approaches have been introduced to increase the signal-to-noise ratio of

chemiluminescent light emission as a molecular signal

This work describes the design and synthesis of a new class of self-immolative chemiluminescent polymers

constructed of four complementary components ) chemically stable 12-dioxatene analog incorporated an

adamantyl group (bulky substituent) ii) protected 4-hydroxybenzyl alcohol substituent (self-immolative

monomeric linker) iii) a chemical or biological responsive group (eg silyl protecting group) and iv) the

monomers are linked together via carbonate linkage

Our results show that a single cleavage event of the protecting group on the phenol results in the formation of a

quinone derivative of 12-dioxetane which undergoes a rapid 16-elimination to release the leaving group on

the benzyl alcohol A nucleophilic attack on the benzylic-methide position initiates a chemically initiated

electron-exchange luminescence (CIEEL) process affording methyl benzoate and light emission

Using this new class of chemiluminescent polymers introduce the ability to design a novel stimuli responsive

chemilumnescent polymers as an amplification systems

9

Synthesis and Evaluation of NPP1 Inhibitors as Potential Drugs for the

Treatment of OsteoarthritisCPPD Disease

Molhm Nassir1 Shani Journo2 Abed Saady1 Uri Arad2 Bilha Fischer1 1Department of Chemistry Bar-Ilan University Ramat-Gan Israel

2Department of Rheumatology Tel Aviv Medical Center and the Faculty of Medicine Tel Aviv

Israel

Overproduction of extracellular pyrophosphate due to hydrolysis of ATP by NPP1 leads to deposition of

pathological Ca2P2O7H2O (CPPD) in cartilage resulting in a degenerative joint disease (CPPD disease) which

has no cure We explored the hypothesis that NPP1 inhibitors may be therapeutic agents for CPPD disease by

inhibiting the hydrolysis of ATP Specifically we synthesized novel analogs of ADP (an NPP1 substrate) in

which the Pab bridging oxygen atom is replaced by a methylene group and a derivative where both Pab

phosphate groups are replaced by sulfonate groups 1 and the Pb phosphate is replaced by a sulfonate isoster 2

In addition we synthesized an ADP analog in which the ribose ring was cleaved and the primary alcohol was

substituted by bis-phosphonate 3 To predict the ability of the derivatives to inhibit NPP1 we evaluated the

affinity and selectivity of the analogs to Zn2+ involved in NPP1rsquos catalytic activity We titrated the analogs with

Zn2+- or Ca2+ ions and monitored the titrations by UV Analogs 1 and 2 selectively coordinated Zn2+ and not

Ca2+ and formed ZnL2 complexes whereas analog 3 showed no affinity for Zn2+ and Ca2+ ions Next analogs

1 2 and 3 have been evaluated for their inhibitory effect on NPP1 in human chondrocytes Analog 3 proved to

be a promising inhibitor reducing NPPase activity in human chondrocytes by 90 at 100 microM vs analogs 1

and 2 (40 and 30 inhibition at 100 microM) Analogs 1 2 and 3 were found to be NPP selective showing no

activity at TNAP In summary analog 3 was found to be an effective and selective NPP1 inhibitor in human

chondrocytes Since analog 3 is a poor Zn2+-chelator we hypothesize that its inhibitory effect may be related to

its high flexibility at NPP1rsquos catalytic site

10

Evaluating the Peptide Structure Prediction Capabilities of a Purely Ab-Initio

Method

Moshe Goldstein13 Moshe Amitay2 1Department of Computer Science Jerusalem College of Technology Jerusalem Israel

2Department of Bioinformatics Jerusalem College of Technology Jerusalem Israel 3The Fritz Haber Research Center The Hebrew University of Jerusalem Jerusalem Israel

Peptides such as hormones and antibiotics play many biological functions Peptides` tertiary structures are of

paramount importance for understanding their function as well as the interactions with other molecules

DEEPSAM[1] (Diffusion Equation Evolutionary Programming Simulated Annealing Method) is a novel purely

ab-initio global optimization algorithm aimed to predict the structure of peptides and proteins from amino acid

sequence without any preliminary assumption This method is an Evolutionary Programming algorithm whose

mutation operators are built by hybridizing the advantages of three well-known optimization methods -

Diffusion Equation Method (DEM) Molecular Dynamics Simulated Annealing (MDSA) and the BFGS quasi-

Newton local minimization method

In principle DEEPSAM requires much less computing resources and is much faster than other structure

prediction methods such as Replica Exchange Molecular Dynamics (REMD) and therefore seems to be more

suitable for industrial use

The goal of this study has been to further evaluate the structure prediction accuracy of the DEEPSAM

algorithm by running it against a large number of known NMR structures of linear peptides (10-20 residues) in

an aqueous environment modeled by the GBSA implicit solvent model

[1] M Goldstein E Fredj and R B Gerber A New Hybrid Algorithm for Finding the Lowest Minima of

Potential Surfaces Approach and Applications to Peptides J of Computational Chemistry vol 32 pp 1785ndash

1800 (2011)

11

Keynote Lecture

Quantification of Polar Organic Reactivity

Herbert Mayr Department of Chemistry Ludwig-Maximilian-University Munich Muenchen Germany

The precision of quantum chemical calculations has reached a level that they can predict the thermodynamics of

organic reactions in the gas phase with an accuracy sometimes even exceeding that of experimental methods In

contrast calculations of reaction pathways in solution are still rather laborious and are predominantly used for

investigating mechanisms of known reactions rather than for designing new synthetic transformations For the

latter purpose linear free energy relationships are still indispensable tools Thus pKa values1 are often used for

estimating relative nucleophilic reactivities and leaving group abilities (nucleofugalities) of certain species A

limitation of these so-called Broslashnsted correlations is the fact that pKa values refer to interactions with the

proton while most reactions considered involve formation or cleavage of bonds to carbon We have therefore

developed a Lewis basicity scale2 with respect to C-centered Lewis acids (carbocations and electron-poor p-

systems) and discuss their correlations with nucleophilicities3 and nucleofugalities Analogous relationships

between Lewis acidities electrophilicities and electrofugalities will also be reported4

1) For a comprehensive collection of pKa values see httpibondnankaieducn

2) Mayr H Ammer J Baidya M Maji B Nigst T A Ofial A R Singer T Am Chem Soc

2015 137 2580minus2599

3) For a collection of nucleophilicity and electrophilicity parameters see

httpwwwcuplmudeocmayrDBintrohtml

4) Mayr H Ofial A R Chem Res 2016 49 952ndash965

12

Pyroelectricity from Non-Polar Crystals Enables Understanding Features of

Crystal Growth and Design

Meir Lahav Elena Meirzadeh Eran Mishuk David Ehre Igor Lubomirsky

Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Pyroelectricity a property of certain crystalline materials is the creation of a temporary surface charge upon

temperature change resulting in an external electric current Thermal movement of the molecules alters their

average positions leading to changes in their dipole moments As a consequence of this property spontaneous

polarization was constricted to the polar directions of the ten polar crystal classes when exposed to temperature

change resulting in the creation of two oppositely charged faces which engender pyroelectricity With the

emergence of modern analytical instruments for measuring electric currents it became possible however to

probe the structures of polar defects and imperfections and near surface polar layers that outline non-polar

crystals In spite of their slight amounts those architectures play indispensible role for the understanding of the

different features that control the macroscopic properties of crystals and provide perceptiveness on the

mechanisms of crystal growth

The following sub-topics will be presented

a) Deciphering the riddle of polarity found in the growth of the centrosymmetric crystals of glycine1-2

b) Enantiomeric disorder within the crystals of DL alanine not detectable by diffraction3

c) Solvent molecules as ldquotailor-maderdquo auxiliary in the control of crystal polymorphism as illustrated with the

three polymorphs of glycine4

d) Pyroelectricity combined with theoretical simulations as a new analytical method for the structure

determination of polar tiny-doped domains in crystals at the molecular level5

(1) Meirzadeh E Sapir L et al JACS 2016 138 14756

(2) Piperno S et al Angew Chem Int Ed 2013 52 6513

(3) Mishuk E et al Cryst Growth Des 2014 14 3839

(4) Meirzadeh E Dishon S work in progress

(5) Meirzadeh E Azuri I et al Nature Com 2016 7 13354

13

Enantioselective Synthesis of Intrinsically Chiral Nanocrystals

Gil Markovich Assaf Ben Moshe Uri Hananel

School of Chemistry Tel Aviv University Tel Aviv Israel

We have recently shown that it is possible to perform an enantioselective synthesis of inorganic nanostructures

made of intrinsically chiral crystals such as a-HgS Te and Se These crystals belonging to the P3121 (or

P3221) chiral space group were grown as nanocrystals in the presence of thiolated chiral molecules such as

cysteine penicillamine or glutathione This led to a preference in the growth of the nanocrystals towards a

certain handedness and consequent strong optical activity

Furthermore in the case of Te nanostructures particular synthesis conditions led to overall chiral shape of the

elongated nanostructures expressed as a twist on the scale of the size of the nanostructures of the order of 100

nm Finally the Te could be easily converted to other materials such as gold or silver telluride while

preserving the chiral shape opening the way to the formation of strongly optically active nanostructures made

of various plasmonic or semiconductor materials

We now demonstrate enantioselective synthesis of another class of materials Lanthanide phosphate hydrate

nanocrystals (also of chiral space group) in the presence of tartaric acid The formed nanocrystals exhibit

substantial degree of circularly polarized luminescence and their enantiomeric excess depends non-linearly on

the enantiomeric excess of the tartaric acid ligands We believe that this system may be useful for studying the

mechanism of enantioselection of the formed nanocrystal seeds in the presence of the chiral molecules

14

Optical Microcavity Devices Containing Organic Materials

Yaakov R Tischler Department of Chemistry Bar-Ilan University Ramat-Gan Israel

When two dielectric mirrors are positioned closely together a half wavelength apart or an integer multiple

thereof they form a Fabry-Peacuterot resonator that can trap light of a specific wavelength for many optical cycles

This resonant light trapping phenomenon is at the heart of vertical cavity surface emitting lasers (VCSELs)

optical switches resonant cavity LEDs and numerous other photonic and optoelectronic devices When organic

materials are situated inside such photonic structures and stability issues are properly addressed amazing

results can be achieved such as strong light-matter coupling at room temperature in both the visible and

infrared (IR) spectral ranges low threshold lasing and super-radiant coupling between molecules Using

microcavities properly designed for use with organics here we show strong light-matter coupling in the mid-IR

spectral range and the first demonstration of a monolayer VCSEL where the gain layer consists of a thin film

of fluorescent dye that is one molecule thick We motivate possible sensor applications for these devices and

discuss the unique physical photochemical and photoelectrochemical processes that can be investigated in

such structures

15

Keynote Lecture

Stability Study of Cation Moieties in Alkaline Anion Exchange Membranes for

Fuel Cell Applications

Dario Dekel1 Charles E Diesendruck2 1Chemical Engineering Technion - Israel Institute of Technology Haifa Israel

2Chemistry Technion - Israel Institute of Technology Haifa Israel

There is an increasing worldwide interest in anion exchange membrane fuel cells (AEMFCs) due to the

potential of this technology to use low cost electrocatalysts promising a considerable cost reduction for new

generation of fuel cell devices However the stability of anion conducting polymers for durable anion exchange

membranes (AEMs) and anion exchange ionomers (AEIs) is still a great concern

Here we present a novel methodology to measure the true alkaline stability of anion conducting polymers to be

used in AEMFCs The new ex-situ technique simulates the environment of an AEMFC during operation where

nucleophilic and basic OH- species in the absence or with scarce amount of water attack the functional groups

of the ionic polymer Using this technique we clearly show the critical effect of water molecules on the alkaline

stability of quaternary ammonium (QA) cations commonly used as functional groups in AEMFCs

The results show that as the water content is reduced the QA cations are more rapidly degraded in the presence

of OH- at room temperature With increasing number of water molecules solvating the hydroxide its

nucleophilicity and basicity are hindered and the QA degradation is significantly slowed These results indicate

that the currently used aqueous alkali ex-situ tests to measure AEM stability may lead to false positive stability

results where anion conducting polymers may appear more alkali stable than they really are

We strongly recommend the adoption of this novel developed technique to measure the true stability of anion

conducting polymers to be used for AEMFCs We believe that this new ex-situ protocol will rapidly lead to

development and selection of best stable polymers for durable and robust AEMFCs

16

Probing the Electrode-Electrolyte Interface in Rechargeable Batteries by Solid

State NMR

Michal Leskes Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Reactions at the electrode-electrolyte interface in lithium ion batteries play a key role in the batteryrsquos

performance and are one of the main causes for cell failure These reactions which lead to the formation of the

solid electrolyte interphase (SEI) ultimately control the reversibility of the cellrsquos Li chemistry and its kinetics

Thus an important part in the development of new high energy storage materials is control over their interfacial

chemistry and reactivity with the electrolyte Nuclear magnetic resonance (NMR) spectroscopy is an excellent

approach for following the formation of interfacial layers as it can detect disordered and heterogeneous phases

providing information on their chemical composition structure and dynamic properties Its main disadvantage

is its low sensitivity which is often a limiting factor when probing the SEI Here Irsquoll describe approaches to

overcome this sensitivity limitation by isotope enrichment as well as the potential of new hyperpolarization

techniques which can provide detailed molecular level insight into the chemistry of the SEI

17

First-Principles Based Studies of Complex Oxide Materials

Ilya Grinberg Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Since their first discovery over 70 years ago complex ferroelectric oxides have been shown to exhibit a wide

variety of physical and chemical properties that enable their use in a broad range of applications In particular

the dynamics in a class of complex ferroelectric solid solutions known as relaxors have been under

investigation due to their glass-like behavior and excellent technological properties Nevertheless despite over

50 years of research the key bonding motifs of relaxor ferroelectrics that give rise to their fascinating properties

such as ultrahigh piezoelectric coefficients high permittivity over a broad temperature range diffuse phase

transition without macroscopic lattice symmetry strong frequency dependence in dielectric response and

phonon anomalies are still subject to debate We use molecular dynamics simulations for the prototypical

Pb(Mg13Nb23)O3-PbTiO3 relaxor material to examine the structure bonding and the spatial and temporal

correlations of relaxors Our simulations show that the unusual properties of relaxors simply stem from the

presence of a multidomain state with an extremely small asymp2-10 nm domain size and that dynamics of relaxors

exhibit striking similarities to those of water arising from the local-environment dependent dipole decoupling

due to chemical bonding variation at particular atomic sites

Ferroelectric materials have also recently attracted increased attention as a candidate class of materials for use

in photovoltaic devices In a series of computational studies of a variety of ferroelectric perovskite oxides we

showed that the physical behaviors of these materials are governed by the simple local structure and chemical

bonding characteristics these can then be modified to rationally design new materials with light absorption

through the visible range that enables the use of these materials in photovoltaic applications

18

Colorimetric Detection of the Early Stages of Aluminum Oxidation Using

Plasmonic Gold NanondashIsland Films

Alexander Tesler1 Eyal Sabatani3 Takumi Sannomiya4 Yishai Feldman2

Alexander Vaskevich1 Israel Rubinstein1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemistry Division Nuclear Research Centre Negev Beer-Sheva Israel

4Materials Science amp Engineering Tokyo Institute of Technology Yokohama Kanagawa

Japan

Corrosion is a natural process of degradation of metallic parts reacting with their environment and is the major

cause of failure of metal structures inndashservice Hence detection of the early stages of environmental oxidation

of metal parts is of great importance Here we present a colorimetric method for monitoring the surface

conditions of aluminum using the localized surface plasmon resonance (LSPR) response of gold nanoparticles

(NPs) prendashdeposited onto the aluminum surface Upon oxidation metallic aluminum transforms to transparent

dielectric aluminum oxide (or hydroxide) In water the formed oxidation product adopts a twondashlayer structure

the bottom layer is thinner and compact while the top layer is thicker and highly porous The gold nanondashisland

layer initially deposited (by evaporationannealing) on the aluminum surface maintains its integrity after

corrosion in water and is located between the two aluminum oxide layers Water oxidation of aluminum

substrates with an overlayer of plasmonic gold nano-islands leads to a pronounced color change which can be

monitored in situ using reflection spectroscopy or colorimetrically by the naked eye Theoretical calculations

show that the major spectral change during corrosion is attributed to the interplay between plasmonic scattering

of the Au NP layer reacting to the changing environment and interference within the bottom aluminum oxide

layer acting as an etalon sandwiched between the Au islands and the underlying aluminum The top porous

oxide layer has only a marginal contribution The results indicate that plasmonic gold NPs are well suited for

realndashtime monitoring of the corrosion kinetics of aluminum and its alloys in aqueous environment and in air

The technique is costndasheffective and can be carried out in the transmission or reflection configuration

19

Vertically Aligned Molybdenum Disulfide for Efficient Lithium Storage

Victor Shokhen1 Yana Miroshnikov1 Gregory Gershinsky1 Noam Gotlib2 Chen Stern2

Doron Naveh2 David Zitoun1 1Chemistry Nanotechnology and Advanced Materials (BINA) Bar-Ilan University

Ramat-Gan Israel 2Faculty of Engineering Bar-Ilan University Ramat-Gan Israel

Layered transition-metal disulfides (LTMDs) have played a prominent role in the development of electronic

energy conversion and storage devices Molybdenum disulfide (MoS2) has been widely investigated as a highly

efficient alternative to existing materials Most fabrication pathways of MoS2 focus on its planar growth on

various substrates to reach high-quality layers with planar orientation (PO) Nevertheless in most energy-

storage applications the most relevant orientation is the vertical alignment (VA) of well-defined layers VA

growth paves the way to highly dense devices with exposed active sites on the surface Here the chemical

vapor deposition (CVD) process has been investigated to grow 2H-MoS2 films hundreds of nanometers thick

with VA stacking The films show large domains of perfectly aligned layers with high crystallinity and density

and low surface roughness CVD-grown VA-MoS2 films show superior behavior in lithium storage with stable

capacity even at a high current density compared to PO-MoS2 films The VA-MoS2 films show a high

reversible capacity of 800 mAhg for lithium storage which corresponds to the full conversion to Mo and Li2S

HR-TEM images of VA-MoS2 Capacity of VA-MoS2 compare to PO-MoS2

20

Tailoring the Electronic Structure of TeY-doped NbBiO4 using Oxygen-

vacancy for All-oxide PV Application A Theoretical and Experimental Study

Vijay Singh Susanta Das David Keller Dan Thomas Major

Department of Chemistry Bar-Ilan University Ramat-Gan Israel

First principles studies of point defects and impurities in semiconductors insulators and metals have become an

integral part of material research over the last few decades1 Point defects and impurities often have decisive

effects on material properties2 3 Recently using density functional theory (DFT) calculations we have revealed

that Bi2O3 is a low band-gap material and the obtained energy band-gap 230 eV lies in the region of PV

interest The observed optical transitions between the valence band (VB) (O-2p states) and the conduction band

(CB) (Bi-6p states) are not allowed due to violation of the dipole selection rule (Δl =+-1) Therefore Bi2O3 is

not a potential absorber material for photovoltaic (PV) applications With the aid of DFT calculations and

experimental measurements we have also studied the NbBiO4 system extensively and our results revealed that

its valence band (VB) and conduction band (CB) consist of optically active states but its large energy band gap

350 eV puts a constraint on its use as an absorber material In the present talk I shall discuss how with the

help of suitable doping as well as oxygen vacancy we managed to reduce the energy band gap of NbBiO4 from

350 eV to 220 eV without changing its electronic structure The observed band-gap is in the region of PV

interest and transitions between the CB and VB states are optically allowed Using COHP (energy resolved

visualization of chemical bonding) calculations we revealed that Y doping in NbBiO4 significantly reduces the

covalent bonding between Bi and nearest neighbors oxygen ions from 100 eVbond to 010 eVbond As a

consequence the computed oxygen defect formation energies for Y-doped NbBiO4 system is lower than the

oxygen defect formation energies of the pure NbBiO4 system contributing to a large oxygen-defect

concentration Thus the significance of oxygen vacancy in Y-doped NbBiO4 (YBi site only) was revealed

and this study might serve to design better PV absorber materials in the future

References

1] Freysoldt C Grabowski B Hickel T Neugebauer J Kresse G Janotti A Van de Walle C G First-

principles calculations for point defects in solids Rev Mod Phys 2014 86 253-305

2] Ganguli N Dasgupta I Sanyal B Electronic structure and magnetism of transition metal doped Zn12O12

clusters Role of defects J Appl Phys 2010 108 123911

3] Yavo N Smith A D Yeheskel O Cohen S Korobko R Wachtel E Slater P R Lubomirsky I

Large Nonclassical Electrostriction in (Y Nb)‐ Stabilized δ‐ Bi2O3 Adv Funct Mater 2016

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

2

Abstracts

Oral Presentations

Monday February 13 2017

3

Plenary Lecture

Oxidized Cytosines as new Epigenetic Bases

Thomas Carell Center for Integrative Protein Science at the Department of Chemistry

Ludwig-Maximilians-University Munich Germany

Epigenetic information is stored in the form of modified bases in the genome The positions and the kind of the

base modifications determines the identity of the corresponding cell Setting and erasing of epigenetic imprints

controls the complete development process starting from an omnipotent stem cells and ending with an adult

specialized cell I am going to discuss the latest results related to the function and distribution of the epigenetic

marker bases 5-hydroxymethylcytosine (hmC) 5-formylcytosine (fC) 5-carboxycytosine (caC) and 5-

hydroxymethyluracil (Scheme 1)[1] These nucleobases control epigenetic programming of stem cells and some

of these bases are also detected at relatively high levels in brain tissues Synthetic routes to these new bases will

be discussed that enable today preparation of oligonucleotides containing the new bases The second part of the

lecture will cover mass spectroscopic approaches to decipher the biological functions of the new epigenetic

bases of which some were described in the past as pure DNA lesions[2] In particular results from quantitative

mass spectrometry new covalent-capture proteomics mass spectrometry and isotope tracing techniques will be

reported The data allow us to unravel the chemistry in stem cells and the protein networks that are controlled

by the epigenetic base modifications[3]

[1] M Wagner J Steinbacher T F Kraus S Michalakis B Hackner T Pfaffeneder A Perera M Muumlller A

Giese H A Kretzschmar T Carell Angew Chem Int Ed 2015 doi 101002anie201502722 Age-

Dependent Levels of 5-Methyl- 5-Hydroxymethyl- and 5-Formylcytosine in Human and Mouse Brain Tissues

[2] Perera D Eisen M Wagner S K Laube A F Kuumlnzel S Koch J Steinbacher E Schulze V Splith N

Mittermeier M Muumlller M Biel T Carell S Michalakis Cell Rep 2015 11 1-12 TET3 Is Recruited by

REST for Context-Specific Hydroxymethylation and Induction of Gene Expression

[3] CG Spruijt F Gnerlich AH Smits T Pfaffeneder PWTC Jansen C Bauer M Muumlnzel M Wagner

M Muumlller F Khan HC Eberl A Mensinga AB Brinkman K Lephikov U Muumlller J Walter R Boelens

H van Ingen H Leonhardt T Carelllowast M Vermeulenlowast Cell 2013 152 1146-59 Dynamic readers for 5-

(hydroxy)methylcytosine and its oxidized derivatives

4

Keynote Lecture

Chemiluminescence Probes with Color Modulation

Doron Shabat Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Chemiluminescence is among the most sensitive methods for achieving a high signal-to-noise ratio in various

chemical and biological applications We have developed a modular practical synthetic route for preparation of

turn-ON dioxetane-tethered fluorophore chemiluminescent probes The chemiluminescent emission of the

probes was significantly amplified through energy transfer mechanism under physiological conditions Two

probes were composed of dioxetane tethered with green and near-infrared (NIR) fluorescent dyes While both

probes were able to provide chemiluminescence in vivo images following subcutaneous injection only the NIR

probe could provide chemiluminescence image following intraperitoneal injection These are the first in vivo

images produced by dioxetane-chemiluminescence probes with no addition of surfactant enhancer We

anticipate that our practical synthetic methodology will be useful for preparation of various chemiluminescent

probes for numerous applications

5

Selenocysteine Chemistry and Total Chemical Synthesis Applied for Accessing

Human Selenoproteins

Norman Metanis Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Once considered a toxic element selenium is now known as an essential element for life For example in

humans it is incorporated in proteins known as selenoproteins containing the 21st encoded amino acid

selenocysteine (Sec) The differences between selenium and sulfur in their redox potentials pKas and

nucleophilicities and electrophilicities give selenium interesting chemistry For example Sec can be used as a

tool for chemical protein synthesis and allowing for site selective modifications It can be also incorporated

into protein sequences to enhance oxidative protein folding This lecture will discuss our recent studies on

chemical protein synthesis using Sec and selective deselenization reactions which convert Sec into Ala or Ser

These advances in chemical protein synthesis bring us closer to accessing naturally occurring selenoproteins

especially human selenoproteins that still await functional characterization

6

Olrsquo Bimane is Learning New Tricks

Flavio Grynszpan1 Partha J Das1 Ankana Roy1 Yael Diskin-Posner2 Iddo Pinkas2

Michael Firer3 Michael Montag1 1Chemical Sciences Ariel University Ariel Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemical Engineering and Biotechnology Ariel University Ariel Israel

Bimanes are hetero-bicyclic molecules that can be readily synthesized in moderate to good yields These low

molecular weight fluorophores were developed by Prof E Kosower and co-workers about 40 years ago[i]

From the two possible diastereomeric forms only syn-bimanes are strongly fluorescent Some bimane

derivatives have become useful as fluorescent probes for different applications ranging from biological labeling

to LASER dyes Recently we showed that when attached to an appropriate carrier moiety syn-bimane can

cross the blood-brain-barrier (BBB) of living mice and be clearly detected in brain tissue[ii] syn-Bimanes

present an N-imide structure as an integral part of their skeleton which in the past was never exploited as a

metal binding motif We showed that a cationic Pd(II) complex (2) containing syn-(MeMe)bimane (1 R1-4 =

Me) as a ligand could be prepared and was fully characterized[iii] We are currently involved in the preparation

of bimane derivatives where the oxygen atoms are replaced by sulfur atoms The novel mono- and di-thioxo-

bimanes are expected to display novel spectroscopic properties and give rise to more stable complexes with

different metals Our latest results with oxo- and thioxo-bimanes their structures chemistry and spectroscopic

studies will be presented

[i] E M Kosower B Pazhenchevsky E Hershkowitz J Am Chem Soc 1978 100 6516

[ii] I Lapidot D Baranes A Pinhasov G Gellerman A Albeck F Grynszpan S E Shatzmiller Med

Chem 2016 12 48

[iii] PJ Das Y Diskin-Posner M Firer M Montag F Grynszpan Dalton Trans 201645 17123-17131

7

Synthesis of Highly Functionalized Alkenylfluorides by Silver-Mediated

Fluorodestannation

Heiko Sommer12 Alois Fuumlrstner1 1Organometallic Chemistry Max-Planck-Institut fuumlr Kohlenforschung Muumllheim an der Ruhr

Germany 2Schulich Faculty of Chemistry Technion - Israel Institute of Technology Haifa Israel

The role of fluorine in synthetic and medicinal chemistry receives an ever-increasing attention as fluorine plays

a unique role in influencing the conformation solubility potency permeability or degradability of small

molecules The late-stage introduction of fluorine is of great interest as it allows the modification of complex

molecules without significantly changing the synthetic route

In conjunction with our previously reported ruthenium-catalyzed directed trans-hydrostannation of internal

alkynes[1] an efficient method for the synthesis of highly elaborate alkenyl fluorides could be implemented

(Scheme 1)[2]

Scheme 1 Hydrostannationfluorodestannation for the synthesis of fluoroolefins

During our studies we developed a mild protocol that allowed us to transform a plethora of alkenylstannanes

into the corresponding fluorides while overcoming competing protodestannation[3] Key to success is the

utilization of the non-hygroscopic salt silver(I) diphenyl phosphinate (AgDPP) as a mediator

We applied this new protocol to the synthesis of highly functionalized biologically relevant compounds

consisting among others of a polyketide derivative a peptide bioisoster and a prostaglandin derivative (Scheme

2)

Scheme 2 Selected examples of the silver-mediated fluorodestannation

Literature

[1] a) S M Rummelt A Fuumlrstner Angew Chem Int Ed 2014 53 3626-3630 b) S M Rummelt K

Radkowski D-A Roşca A Fuumlrstner J Am Chem Soc 2015 137 5506-5519

[2] H Sommer A Fuumlrstner submitted manuscript 2016

[3] M A Tius J K Kawakami Tetrahedron 1995 51 3997-4010

8

Stimuli-responsive Self-immolative Chemiluminescent Polymers

Samer Gnaim Doron Shabat

Organic Chemistry Tel Aviv University Tel Aviv Israel

Molecular probes based on 3-hydroxyphenyl-12-dioxetane chemiluminescence light emission are widely used

for various sensing and diagnostic applications (eg DNA enzymatic and chemical probes) Amplification of

molecular signals is an important task for the development of sensitive diagnostic probes in the field of

chemical sensing Recently various approaches have been introduced to increase the signal-to-noise ratio of

chemiluminescent light emission as a molecular signal

This work describes the design and synthesis of a new class of self-immolative chemiluminescent polymers

constructed of four complementary components ) chemically stable 12-dioxatene analog incorporated an

adamantyl group (bulky substituent) ii) protected 4-hydroxybenzyl alcohol substituent (self-immolative

monomeric linker) iii) a chemical or biological responsive group (eg silyl protecting group) and iv) the

monomers are linked together via carbonate linkage

Our results show that a single cleavage event of the protecting group on the phenol results in the formation of a

quinone derivative of 12-dioxetane which undergoes a rapid 16-elimination to release the leaving group on

the benzyl alcohol A nucleophilic attack on the benzylic-methide position initiates a chemically initiated

electron-exchange luminescence (CIEEL) process affording methyl benzoate and light emission

Using this new class of chemiluminescent polymers introduce the ability to design a novel stimuli responsive

chemilumnescent polymers as an amplification systems

9

Synthesis and Evaluation of NPP1 Inhibitors as Potential Drugs for the

Treatment of OsteoarthritisCPPD Disease

Molhm Nassir1 Shani Journo2 Abed Saady1 Uri Arad2 Bilha Fischer1 1Department of Chemistry Bar-Ilan University Ramat-Gan Israel

2Department of Rheumatology Tel Aviv Medical Center and the Faculty of Medicine Tel Aviv

Israel

Overproduction of extracellular pyrophosphate due to hydrolysis of ATP by NPP1 leads to deposition of

pathological Ca2P2O7H2O (CPPD) in cartilage resulting in a degenerative joint disease (CPPD disease) which

has no cure We explored the hypothesis that NPP1 inhibitors may be therapeutic agents for CPPD disease by

inhibiting the hydrolysis of ATP Specifically we synthesized novel analogs of ADP (an NPP1 substrate) in

which the Pab bridging oxygen atom is replaced by a methylene group and a derivative where both Pab

phosphate groups are replaced by sulfonate groups 1 and the Pb phosphate is replaced by a sulfonate isoster 2

In addition we synthesized an ADP analog in which the ribose ring was cleaved and the primary alcohol was

substituted by bis-phosphonate 3 To predict the ability of the derivatives to inhibit NPP1 we evaluated the

affinity and selectivity of the analogs to Zn2+ involved in NPP1rsquos catalytic activity We titrated the analogs with

Zn2+- or Ca2+ ions and monitored the titrations by UV Analogs 1 and 2 selectively coordinated Zn2+ and not

Ca2+ and formed ZnL2 complexes whereas analog 3 showed no affinity for Zn2+ and Ca2+ ions Next analogs

1 2 and 3 have been evaluated for their inhibitory effect on NPP1 in human chondrocytes Analog 3 proved to

be a promising inhibitor reducing NPPase activity in human chondrocytes by 90 at 100 microM vs analogs 1

and 2 (40 and 30 inhibition at 100 microM) Analogs 1 2 and 3 were found to be NPP selective showing no

activity at TNAP In summary analog 3 was found to be an effective and selective NPP1 inhibitor in human

chondrocytes Since analog 3 is a poor Zn2+-chelator we hypothesize that its inhibitory effect may be related to

its high flexibility at NPP1rsquos catalytic site

10

Evaluating the Peptide Structure Prediction Capabilities of a Purely Ab-Initio

Method

Moshe Goldstein13 Moshe Amitay2 1Department of Computer Science Jerusalem College of Technology Jerusalem Israel

2Department of Bioinformatics Jerusalem College of Technology Jerusalem Israel 3The Fritz Haber Research Center The Hebrew University of Jerusalem Jerusalem Israel

Peptides such as hormones and antibiotics play many biological functions Peptides` tertiary structures are of

paramount importance for understanding their function as well as the interactions with other molecules

DEEPSAM[1] (Diffusion Equation Evolutionary Programming Simulated Annealing Method) is a novel purely

ab-initio global optimization algorithm aimed to predict the structure of peptides and proteins from amino acid

sequence without any preliminary assumption This method is an Evolutionary Programming algorithm whose

mutation operators are built by hybridizing the advantages of three well-known optimization methods -

Diffusion Equation Method (DEM) Molecular Dynamics Simulated Annealing (MDSA) and the BFGS quasi-

Newton local minimization method

In principle DEEPSAM requires much less computing resources and is much faster than other structure

prediction methods such as Replica Exchange Molecular Dynamics (REMD) and therefore seems to be more

suitable for industrial use

The goal of this study has been to further evaluate the structure prediction accuracy of the DEEPSAM

algorithm by running it against a large number of known NMR structures of linear peptides (10-20 residues) in

an aqueous environment modeled by the GBSA implicit solvent model

[1] M Goldstein E Fredj and R B Gerber A New Hybrid Algorithm for Finding the Lowest Minima of

Potential Surfaces Approach and Applications to Peptides J of Computational Chemistry vol 32 pp 1785ndash

1800 (2011)

11

Keynote Lecture

Quantification of Polar Organic Reactivity

Herbert Mayr Department of Chemistry Ludwig-Maximilian-University Munich Muenchen Germany

The precision of quantum chemical calculations has reached a level that they can predict the thermodynamics of

organic reactions in the gas phase with an accuracy sometimes even exceeding that of experimental methods In

contrast calculations of reaction pathways in solution are still rather laborious and are predominantly used for

investigating mechanisms of known reactions rather than for designing new synthetic transformations For the

latter purpose linear free energy relationships are still indispensable tools Thus pKa values1 are often used for

estimating relative nucleophilic reactivities and leaving group abilities (nucleofugalities) of certain species A

limitation of these so-called Broslashnsted correlations is the fact that pKa values refer to interactions with the

proton while most reactions considered involve formation or cleavage of bonds to carbon We have therefore

developed a Lewis basicity scale2 with respect to C-centered Lewis acids (carbocations and electron-poor p-

systems) and discuss their correlations with nucleophilicities3 and nucleofugalities Analogous relationships

between Lewis acidities electrophilicities and electrofugalities will also be reported4

1) For a comprehensive collection of pKa values see httpibondnankaieducn

2) Mayr H Ammer J Baidya M Maji B Nigst T A Ofial A R Singer T Am Chem Soc

2015 137 2580minus2599

3) For a collection of nucleophilicity and electrophilicity parameters see

httpwwwcuplmudeocmayrDBintrohtml

4) Mayr H Ofial A R Chem Res 2016 49 952ndash965

12

Pyroelectricity from Non-Polar Crystals Enables Understanding Features of

Crystal Growth and Design

Meir Lahav Elena Meirzadeh Eran Mishuk David Ehre Igor Lubomirsky

Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Pyroelectricity a property of certain crystalline materials is the creation of a temporary surface charge upon

temperature change resulting in an external electric current Thermal movement of the molecules alters their

average positions leading to changes in their dipole moments As a consequence of this property spontaneous

polarization was constricted to the polar directions of the ten polar crystal classes when exposed to temperature

change resulting in the creation of two oppositely charged faces which engender pyroelectricity With the

emergence of modern analytical instruments for measuring electric currents it became possible however to

probe the structures of polar defects and imperfections and near surface polar layers that outline non-polar

crystals In spite of their slight amounts those architectures play indispensible role for the understanding of the

different features that control the macroscopic properties of crystals and provide perceptiveness on the

mechanisms of crystal growth

The following sub-topics will be presented

a) Deciphering the riddle of polarity found in the growth of the centrosymmetric crystals of glycine1-2

b) Enantiomeric disorder within the crystals of DL alanine not detectable by diffraction3

c) Solvent molecules as ldquotailor-maderdquo auxiliary in the control of crystal polymorphism as illustrated with the

three polymorphs of glycine4

d) Pyroelectricity combined with theoretical simulations as a new analytical method for the structure

determination of polar tiny-doped domains in crystals at the molecular level5

(1) Meirzadeh E Sapir L et al JACS 2016 138 14756

(2) Piperno S et al Angew Chem Int Ed 2013 52 6513

(3) Mishuk E et al Cryst Growth Des 2014 14 3839

(4) Meirzadeh E Dishon S work in progress

(5) Meirzadeh E Azuri I et al Nature Com 2016 7 13354

13

Enantioselective Synthesis of Intrinsically Chiral Nanocrystals

Gil Markovich Assaf Ben Moshe Uri Hananel

School of Chemistry Tel Aviv University Tel Aviv Israel

We have recently shown that it is possible to perform an enantioselective synthesis of inorganic nanostructures

made of intrinsically chiral crystals such as a-HgS Te and Se These crystals belonging to the P3121 (or

P3221) chiral space group were grown as nanocrystals in the presence of thiolated chiral molecules such as

cysteine penicillamine or glutathione This led to a preference in the growth of the nanocrystals towards a

certain handedness and consequent strong optical activity

Furthermore in the case of Te nanostructures particular synthesis conditions led to overall chiral shape of the

elongated nanostructures expressed as a twist on the scale of the size of the nanostructures of the order of 100

nm Finally the Te could be easily converted to other materials such as gold or silver telluride while

preserving the chiral shape opening the way to the formation of strongly optically active nanostructures made

of various plasmonic or semiconductor materials

We now demonstrate enantioselective synthesis of another class of materials Lanthanide phosphate hydrate

nanocrystals (also of chiral space group) in the presence of tartaric acid The formed nanocrystals exhibit

substantial degree of circularly polarized luminescence and their enantiomeric excess depends non-linearly on

the enantiomeric excess of the tartaric acid ligands We believe that this system may be useful for studying the

mechanism of enantioselection of the formed nanocrystal seeds in the presence of the chiral molecules

14

Optical Microcavity Devices Containing Organic Materials

Yaakov R Tischler Department of Chemistry Bar-Ilan University Ramat-Gan Israel

When two dielectric mirrors are positioned closely together a half wavelength apart or an integer multiple

thereof they form a Fabry-Peacuterot resonator that can trap light of a specific wavelength for many optical cycles

This resonant light trapping phenomenon is at the heart of vertical cavity surface emitting lasers (VCSELs)

optical switches resonant cavity LEDs and numerous other photonic and optoelectronic devices When organic

materials are situated inside such photonic structures and stability issues are properly addressed amazing

results can be achieved such as strong light-matter coupling at room temperature in both the visible and

infrared (IR) spectral ranges low threshold lasing and super-radiant coupling between molecules Using

microcavities properly designed for use with organics here we show strong light-matter coupling in the mid-IR

spectral range and the first demonstration of a monolayer VCSEL where the gain layer consists of a thin film

of fluorescent dye that is one molecule thick We motivate possible sensor applications for these devices and

discuss the unique physical photochemical and photoelectrochemical processes that can be investigated in

such structures

15

Keynote Lecture

Stability Study of Cation Moieties in Alkaline Anion Exchange Membranes for

Fuel Cell Applications

Dario Dekel1 Charles E Diesendruck2 1Chemical Engineering Technion - Israel Institute of Technology Haifa Israel

2Chemistry Technion - Israel Institute of Technology Haifa Israel

There is an increasing worldwide interest in anion exchange membrane fuel cells (AEMFCs) due to the

potential of this technology to use low cost electrocatalysts promising a considerable cost reduction for new

generation of fuel cell devices However the stability of anion conducting polymers for durable anion exchange

membranes (AEMs) and anion exchange ionomers (AEIs) is still a great concern

Here we present a novel methodology to measure the true alkaline stability of anion conducting polymers to be

used in AEMFCs The new ex-situ technique simulates the environment of an AEMFC during operation where

nucleophilic and basic OH- species in the absence or with scarce amount of water attack the functional groups

of the ionic polymer Using this technique we clearly show the critical effect of water molecules on the alkaline

stability of quaternary ammonium (QA) cations commonly used as functional groups in AEMFCs

The results show that as the water content is reduced the QA cations are more rapidly degraded in the presence

of OH- at room temperature With increasing number of water molecules solvating the hydroxide its

nucleophilicity and basicity are hindered and the QA degradation is significantly slowed These results indicate

that the currently used aqueous alkali ex-situ tests to measure AEM stability may lead to false positive stability

results where anion conducting polymers may appear more alkali stable than they really are

We strongly recommend the adoption of this novel developed technique to measure the true stability of anion

conducting polymers to be used for AEMFCs We believe that this new ex-situ protocol will rapidly lead to

development and selection of best stable polymers for durable and robust AEMFCs

16

Probing the Electrode-Electrolyte Interface in Rechargeable Batteries by Solid

State NMR

Michal Leskes Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Reactions at the electrode-electrolyte interface in lithium ion batteries play a key role in the batteryrsquos

performance and are one of the main causes for cell failure These reactions which lead to the formation of the

solid electrolyte interphase (SEI) ultimately control the reversibility of the cellrsquos Li chemistry and its kinetics

Thus an important part in the development of new high energy storage materials is control over their interfacial

chemistry and reactivity with the electrolyte Nuclear magnetic resonance (NMR) spectroscopy is an excellent

approach for following the formation of interfacial layers as it can detect disordered and heterogeneous phases

providing information on their chemical composition structure and dynamic properties Its main disadvantage

is its low sensitivity which is often a limiting factor when probing the SEI Here Irsquoll describe approaches to

overcome this sensitivity limitation by isotope enrichment as well as the potential of new hyperpolarization

techniques which can provide detailed molecular level insight into the chemistry of the SEI

17

First-Principles Based Studies of Complex Oxide Materials

Ilya Grinberg Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Since their first discovery over 70 years ago complex ferroelectric oxides have been shown to exhibit a wide

variety of physical and chemical properties that enable their use in a broad range of applications In particular

the dynamics in a class of complex ferroelectric solid solutions known as relaxors have been under

investigation due to their glass-like behavior and excellent technological properties Nevertheless despite over

50 years of research the key bonding motifs of relaxor ferroelectrics that give rise to their fascinating properties

such as ultrahigh piezoelectric coefficients high permittivity over a broad temperature range diffuse phase

transition without macroscopic lattice symmetry strong frequency dependence in dielectric response and

phonon anomalies are still subject to debate We use molecular dynamics simulations for the prototypical

Pb(Mg13Nb23)O3-PbTiO3 relaxor material to examine the structure bonding and the spatial and temporal

correlations of relaxors Our simulations show that the unusual properties of relaxors simply stem from the

presence of a multidomain state with an extremely small asymp2-10 nm domain size and that dynamics of relaxors

exhibit striking similarities to those of water arising from the local-environment dependent dipole decoupling

due to chemical bonding variation at particular atomic sites

Ferroelectric materials have also recently attracted increased attention as a candidate class of materials for use

in photovoltaic devices In a series of computational studies of a variety of ferroelectric perovskite oxides we

showed that the physical behaviors of these materials are governed by the simple local structure and chemical

bonding characteristics these can then be modified to rationally design new materials with light absorption

through the visible range that enables the use of these materials in photovoltaic applications

18

Colorimetric Detection of the Early Stages of Aluminum Oxidation Using

Plasmonic Gold NanondashIsland Films

Alexander Tesler1 Eyal Sabatani3 Takumi Sannomiya4 Yishai Feldman2

Alexander Vaskevich1 Israel Rubinstein1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemistry Division Nuclear Research Centre Negev Beer-Sheva Israel

4Materials Science amp Engineering Tokyo Institute of Technology Yokohama Kanagawa

Japan

Corrosion is a natural process of degradation of metallic parts reacting with their environment and is the major

cause of failure of metal structures inndashservice Hence detection of the early stages of environmental oxidation

of metal parts is of great importance Here we present a colorimetric method for monitoring the surface

conditions of aluminum using the localized surface plasmon resonance (LSPR) response of gold nanoparticles

(NPs) prendashdeposited onto the aluminum surface Upon oxidation metallic aluminum transforms to transparent

dielectric aluminum oxide (or hydroxide) In water the formed oxidation product adopts a twondashlayer structure

the bottom layer is thinner and compact while the top layer is thicker and highly porous The gold nanondashisland

layer initially deposited (by evaporationannealing) on the aluminum surface maintains its integrity after

corrosion in water and is located between the two aluminum oxide layers Water oxidation of aluminum

substrates with an overlayer of plasmonic gold nano-islands leads to a pronounced color change which can be

monitored in situ using reflection spectroscopy or colorimetrically by the naked eye Theoretical calculations

show that the major spectral change during corrosion is attributed to the interplay between plasmonic scattering

of the Au NP layer reacting to the changing environment and interference within the bottom aluminum oxide

layer acting as an etalon sandwiched between the Au islands and the underlying aluminum The top porous

oxide layer has only a marginal contribution The results indicate that plasmonic gold NPs are well suited for

realndashtime monitoring of the corrosion kinetics of aluminum and its alloys in aqueous environment and in air

The technique is costndasheffective and can be carried out in the transmission or reflection configuration

19

Vertically Aligned Molybdenum Disulfide for Efficient Lithium Storage

Victor Shokhen1 Yana Miroshnikov1 Gregory Gershinsky1 Noam Gotlib2 Chen Stern2

Doron Naveh2 David Zitoun1 1Chemistry Nanotechnology and Advanced Materials (BINA) Bar-Ilan University

Ramat-Gan Israel 2Faculty of Engineering Bar-Ilan University Ramat-Gan Israel

Layered transition-metal disulfides (LTMDs) have played a prominent role in the development of electronic

energy conversion and storage devices Molybdenum disulfide (MoS2) has been widely investigated as a highly

efficient alternative to existing materials Most fabrication pathways of MoS2 focus on its planar growth on

various substrates to reach high-quality layers with planar orientation (PO) Nevertheless in most energy-

storage applications the most relevant orientation is the vertical alignment (VA) of well-defined layers VA

growth paves the way to highly dense devices with exposed active sites on the surface Here the chemical

vapor deposition (CVD) process has been investigated to grow 2H-MoS2 films hundreds of nanometers thick

with VA stacking The films show large domains of perfectly aligned layers with high crystallinity and density

and low surface roughness CVD-grown VA-MoS2 films show superior behavior in lithium storage with stable

capacity even at a high current density compared to PO-MoS2 films The VA-MoS2 films show a high

reversible capacity of 800 mAhg for lithium storage which corresponds to the full conversion to Mo and Li2S

HR-TEM images of VA-MoS2 Capacity of VA-MoS2 compare to PO-MoS2

20

Tailoring the Electronic Structure of TeY-doped NbBiO4 using Oxygen-

vacancy for All-oxide PV Application A Theoretical and Experimental Study

Vijay Singh Susanta Das David Keller Dan Thomas Major

Department of Chemistry Bar-Ilan University Ramat-Gan Israel

First principles studies of point defects and impurities in semiconductors insulators and metals have become an

integral part of material research over the last few decades1 Point defects and impurities often have decisive

effects on material properties2 3 Recently using density functional theory (DFT) calculations we have revealed

that Bi2O3 is a low band-gap material and the obtained energy band-gap 230 eV lies in the region of PV

interest The observed optical transitions between the valence band (VB) (O-2p states) and the conduction band

(CB) (Bi-6p states) are not allowed due to violation of the dipole selection rule (Δl =+-1) Therefore Bi2O3 is

not a potential absorber material for photovoltaic (PV) applications With the aid of DFT calculations and

experimental measurements we have also studied the NbBiO4 system extensively and our results revealed that

its valence band (VB) and conduction band (CB) consist of optically active states but its large energy band gap

350 eV puts a constraint on its use as an absorber material In the present talk I shall discuss how with the

help of suitable doping as well as oxygen vacancy we managed to reduce the energy band gap of NbBiO4 from

350 eV to 220 eV without changing its electronic structure The observed band-gap is in the region of PV

interest and transitions between the CB and VB states are optically allowed Using COHP (energy resolved

visualization of chemical bonding) calculations we revealed that Y doping in NbBiO4 significantly reduces the

covalent bonding between Bi and nearest neighbors oxygen ions from 100 eVbond to 010 eVbond As a

consequence the computed oxygen defect formation energies for Y-doped NbBiO4 system is lower than the

oxygen defect formation energies of the pure NbBiO4 system contributing to a large oxygen-defect

concentration Thus the significance of oxygen vacancy in Y-doped NbBiO4 (YBi site only) was revealed

and this study might serve to design better PV absorber materials in the future

References

1] Freysoldt C Grabowski B Hickel T Neugebauer J Kresse G Janotti A Van de Walle C G First-

principles calculations for point defects in solids Rev Mod Phys 2014 86 253-305

2] Ganguli N Dasgupta I Sanyal B Electronic structure and magnetism of transition metal doped Zn12O12

clusters Role of defects J Appl Phys 2010 108 123911

3] Yavo N Smith A D Yeheskel O Cohen S Korobko R Wachtel E Slater P R Lubomirsky I

Large Nonclassical Electrostriction in (Y Nb)‐ Stabilized δ‐ Bi2O3 Adv Funct Mater 2016

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

3

Plenary Lecture

Oxidized Cytosines as new Epigenetic Bases

Thomas Carell Center for Integrative Protein Science at the Department of Chemistry

Ludwig-Maximilians-University Munich Germany

Epigenetic information is stored in the form of modified bases in the genome The positions and the kind of the

base modifications determines the identity of the corresponding cell Setting and erasing of epigenetic imprints

controls the complete development process starting from an omnipotent stem cells and ending with an adult

specialized cell I am going to discuss the latest results related to the function and distribution of the epigenetic

marker bases 5-hydroxymethylcytosine (hmC) 5-formylcytosine (fC) 5-carboxycytosine (caC) and 5-

hydroxymethyluracil (Scheme 1)[1] These nucleobases control epigenetic programming of stem cells and some

of these bases are also detected at relatively high levels in brain tissues Synthetic routes to these new bases will

be discussed that enable today preparation of oligonucleotides containing the new bases The second part of the

lecture will cover mass spectroscopic approaches to decipher the biological functions of the new epigenetic

bases of which some were described in the past as pure DNA lesions[2] In particular results from quantitative

mass spectrometry new covalent-capture proteomics mass spectrometry and isotope tracing techniques will be

reported The data allow us to unravel the chemistry in stem cells and the protein networks that are controlled

by the epigenetic base modifications[3]

[1] M Wagner J Steinbacher T F Kraus S Michalakis B Hackner T Pfaffeneder A Perera M Muumlller A

Giese H A Kretzschmar T Carell Angew Chem Int Ed 2015 doi 101002anie201502722 Age-

Dependent Levels of 5-Methyl- 5-Hydroxymethyl- and 5-Formylcytosine in Human and Mouse Brain Tissues

[2] Perera D Eisen M Wagner S K Laube A F Kuumlnzel S Koch J Steinbacher E Schulze V Splith N

Mittermeier M Muumlller M Biel T Carell S Michalakis Cell Rep 2015 11 1-12 TET3 Is Recruited by

REST for Context-Specific Hydroxymethylation and Induction of Gene Expression

[3] CG Spruijt F Gnerlich AH Smits T Pfaffeneder PWTC Jansen C Bauer M Muumlnzel M Wagner

M Muumlller F Khan HC Eberl A Mensinga AB Brinkman K Lephikov U Muumlller J Walter R Boelens

H van Ingen H Leonhardt T Carelllowast M Vermeulenlowast Cell 2013 152 1146-59 Dynamic readers for 5-

(hydroxy)methylcytosine and its oxidized derivatives

4

Keynote Lecture

Chemiluminescence Probes with Color Modulation

Doron Shabat Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Chemiluminescence is among the most sensitive methods for achieving a high signal-to-noise ratio in various

chemical and biological applications We have developed a modular practical synthetic route for preparation of

turn-ON dioxetane-tethered fluorophore chemiluminescent probes The chemiluminescent emission of the

probes was significantly amplified through energy transfer mechanism under physiological conditions Two

probes were composed of dioxetane tethered with green and near-infrared (NIR) fluorescent dyes While both

probes were able to provide chemiluminescence in vivo images following subcutaneous injection only the NIR

probe could provide chemiluminescence image following intraperitoneal injection These are the first in vivo

images produced by dioxetane-chemiluminescence probes with no addition of surfactant enhancer We

anticipate that our practical synthetic methodology will be useful for preparation of various chemiluminescent

probes for numerous applications

5

Selenocysteine Chemistry and Total Chemical Synthesis Applied for Accessing

Human Selenoproteins

Norman Metanis Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Once considered a toxic element selenium is now known as an essential element for life For example in

humans it is incorporated in proteins known as selenoproteins containing the 21st encoded amino acid

selenocysteine (Sec) The differences between selenium and sulfur in their redox potentials pKas and

nucleophilicities and electrophilicities give selenium interesting chemistry For example Sec can be used as a

tool for chemical protein synthesis and allowing for site selective modifications It can be also incorporated

into protein sequences to enhance oxidative protein folding This lecture will discuss our recent studies on

chemical protein synthesis using Sec and selective deselenization reactions which convert Sec into Ala or Ser

These advances in chemical protein synthesis bring us closer to accessing naturally occurring selenoproteins

especially human selenoproteins that still await functional characterization

6

Olrsquo Bimane is Learning New Tricks

Flavio Grynszpan1 Partha J Das1 Ankana Roy1 Yael Diskin-Posner2 Iddo Pinkas2

Michael Firer3 Michael Montag1 1Chemical Sciences Ariel University Ariel Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemical Engineering and Biotechnology Ariel University Ariel Israel

Bimanes are hetero-bicyclic molecules that can be readily synthesized in moderate to good yields These low

molecular weight fluorophores were developed by Prof E Kosower and co-workers about 40 years ago[i]

From the two possible diastereomeric forms only syn-bimanes are strongly fluorescent Some bimane

derivatives have become useful as fluorescent probes for different applications ranging from biological labeling

to LASER dyes Recently we showed that when attached to an appropriate carrier moiety syn-bimane can

cross the blood-brain-barrier (BBB) of living mice and be clearly detected in brain tissue[ii] syn-Bimanes

present an N-imide structure as an integral part of their skeleton which in the past was never exploited as a

metal binding motif We showed that a cationic Pd(II) complex (2) containing syn-(MeMe)bimane (1 R1-4 =

Me) as a ligand could be prepared and was fully characterized[iii] We are currently involved in the preparation

of bimane derivatives where the oxygen atoms are replaced by sulfur atoms The novel mono- and di-thioxo-

bimanes are expected to display novel spectroscopic properties and give rise to more stable complexes with

different metals Our latest results with oxo- and thioxo-bimanes their structures chemistry and spectroscopic

studies will be presented

[i] E M Kosower B Pazhenchevsky E Hershkowitz J Am Chem Soc 1978 100 6516

[ii] I Lapidot D Baranes A Pinhasov G Gellerman A Albeck F Grynszpan S E Shatzmiller Med

Chem 2016 12 48

[iii] PJ Das Y Diskin-Posner M Firer M Montag F Grynszpan Dalton Trans 201645 17123-17131

7

Synthesis of Highly Functionalized Alkenylfluorides by Silver-Mediated

Fluorodestannation

Heiko Sommer12 Alois Fuumlrstner1 1Organometallic Chemistry Max-Planck-Institut fuumlr Kohlenforschung Muumllheim an der Ruhr

Germany 2Schulich Faculty of Chemistry Technion - Israel Institute of Technology Haifa Israel

The role of fluorine in synthetic and medicinal chemistry receives an ever-increasing attention as fluorine plays

a unique role in influencing the conformation solubility potency permeability or degradability of small

molecules The late-stage introduction of fluorine is of great interest as it allows the modification of complex

molecules without significantly changing the synthetic route

In conjunction with our previously reported ruthenium-catalyzed directed trans-hydrostannation of internal

alkynes[1] an efficient method for the synthesis of highly elaborate alkenyl fluorides could be implemented

(Scheme 1)[2]

Scheme 1 Hydrostannationfluorodestannation for the synthesis of fluoroolefins

During our studies we developed a mild protocol that allowed us to transform a plethora of alkenylstannanes

into the corresponding fluorides while overcoming competing protodestannation[3] Key to success is the

utilization of the non-hygroscopic salt silver(I) diphenyl phosphinate (AgDPP) as a mediator

We applied this new protocol to the synthesis of highly functionalized biologically relevant compounds

consisting among others of a polyketide derivative a peptide bioisoster and a prostaglandin derivative (Scheme

2)

Scheme 2 Selected examples of the silver-mediated fluorodestannation

Literature

[1] a) S M Rummelt A Fuumlrstner Angew Chem Int Ed 2014 53 3626-3630 b) S M Rummelt K

Radkowski D-A Roşca A Fuumlrstner J Am Chem Soc 2015 137 5506-5519

[2] H Sommer A Fuumlrstner submitted manuscript 2016

[3] M A Tius J K Kawakami Tetrahedron 1995 51 3997-4010

8

Stimuli-responsive Self-immolative Chemiluminescent Polymers

Samer Gnaim Doron Shabat

Organic Chemistry Tel Aviv University Tel Aviv Israel

Molecular probes based on 3-hydroxyphenyl-12-dioxetane chemiluminescence light emission are widely used

for various sensing and diagnostic applications (eg DNA enzymatic and chemical probes) Amplification of

molecular signals is an important task for the development of sensitive diagnostic probes in the field of

chemical sensing Recently various approaches have been introduced to increase the signal-to-noise ratio of

chemiluminescent light emission as a molecular signal

This work describes the design and synthesis of a new class of self-immolative chemiluminescent polymers

constructed of four complementary components ) chemically stable 12-dioxatene analog incorporated an

adamantyl group (bulky substituent) ii) protected 4-hydroxybenzyl alcohol substituent (self-immolative

monomeric linker) iii) a chemical or biological responsive group (eg silyl protecting group) and iv) the

monomers are linked together via carbonate linkage

Our results show that a single cleavage event of the protecting group on the phenol results in the formation of a

quinone derivative of 12-dioxetane which undergoes a rapid 16-elimination to release the leaving group on

the benzyl alcohol A nucleophilic attack on the benzylic-methide position initiates a chemically initiated

electron-exchange luminescence (CIEEL) process affording methyl benzoate and light emission

Using this new class of chemiluminescent polymers introduce the ability to design a novel stimuli responsive

chemilumnescent polymers as an amplification systems

9

Synthesis and Evaluation of NPP1 Inhibitors as Potential Drugs for the

Treatment of OsteoarthritisCPPD Disease

Molhm Nassir1 Shani Journo2 Abed Saady1 Uri Arad2 Bilha Fischer1 1Department of Chemistry Bar-Ilan University Ramat-Gan Israel

2Department of Rheumatology Tel Aviv Medical Center and the Faculty of Medicine Tel Aviv

Israel

Overproduction of extracellular pyrophosphate due to hydrolysis of ATP by NPP1 leads to deposition of

pathological Ca2P2O7H2O (CPPD) in cartilage resulting in a degenerative joint disease (CPPD disease) which

has no cure We explored the hypothesis that NPP1 inhibitors may be therapeutic agents for CPPD disease by

inhibiting the hydrolysis of ATP Specifically we synthesized novel analogs of ADP (an NPP1 substrate) in

which the Pab bridging oxygen atom is replaced by a methylene group and a derivative where both Pab

phosphate groups are replaced by sulfonate groups 1 and the Pb phosphate is replaced by a sulfonate isoster 2

In addition we synthesized an ADP analog in which the ribose ring was cleaved and the primary alcohol was

substituted by bis-phosphonate 3 To predict the ability of the derivatives to inhibit NPP1 we evaluated the

affinity and selectivity of the analogs to Zn2+ involved in NPP1rsquos catalytic activity We titrated the analogs with

Zn2+- or Ca2+ ions and monitored the titrations by UV Analogs 1 and 2 selectively coordinated Zn2+ and not

Ca2+ and formed ZnL2 complexes whereas analog 3 showed no affinity for Zn2+ and Ca2+ ions Next analogs

1 2 and 3 have been evaluated for their inhibitory effect on NPP1 in human chondrocytes Analog 3 proved to

be a promising inhibitor reducing NPPase activity in human chondrocytes by 90 at 100 microM vs analogs 1

and 2 (40 and 30 inhibition at 100 microM) Analogs 1 2 and 3 were found to be NPP selective showing no

activity at TNAP In summary analog 3 was found to be an effective and selective NPP1 inhibitor in human

chondrocytes Since analog 3 is a poor Zn2+-chelator we hypothesize that its inhibitory effect may be related to

its high flexibility at NPP1rsquos catalytic site

10

Evaluating the Peptide Structure Prediction Capabilities of a Purely Ab-Initio

Method

Moshe Goldstein13 Moshe Amitay2 1Department of Computer Science Jerusalem College of Technology Jerusalem Israel

2Department of Bioinformatics Jerusalem College of Technology Jerusalem Israel 3The Fritz Haber Research Center The Hebrew University of Jerusalem Jerusalem Israel

Peptides such as hormones and antibiotics play many biological functions Peptides` tertiary structures are of

paramount importance for understanding their function as well as the interactions with other molecules

DEEPSAM[1] (Diffusion Equation Evolutionary Programming Simulated Annealing Method) is a novel purely

ab-initio global optimization algorithm aimed to predict the structure of peptides and proteins from amino acid

sequence without any preliminary assumption This method is an Evolutionary Programming algorithm whose

mutation operators are built by hybridizing the advantages of three well-known optimization methods -

Diffusion Equation Method (DEM) Molecular Dynamics Simulated Annealing (MDSA) and the BFGS quasi-

Newton local minimization method

In principle DEEPSAM requires much less computing resources and is much faster than other structure

prediction methods such as Replica Exchange Molecular Dynamics (REMD) and therefore seems to be more

suitable for industrial use

The goal of this study has been to further evaluate the structure prediction accuracy of the DEEPSAM

algorithm by running it against a large number of known NMR structures of linear peptides (10-20 residues) in

an aqueous environment modeled by the GBSA implicit solvent model

[1] M Goldstein E Fredj and R B Gerber A New Hybrid Algorithm for Finding the Lowest Minima of

Potential Surfaces Approach and Applications to Peptides J of Computational Chemistry vol 32 pp 1785ndash

1800 (2011)

11

Keynote Lecture

Quantification of Polar Organic Reactivity

Herbert Mayr Department of Chemistry Ludwig-Maximilian-University Munich Muenchen Germany

The precision of quantum chemical calculations has reached a level that they can predict the thermodynamics of

organic reactions in the gas phase with an accuracy sometimes even exceeding that of experimental methods In

contrast calculations of reaction pathways in solution are still rather laborious and are predominantly used for

investigating mechanisms of known reactions rather than for designing new synthetic transformations For the

latter purpose linear free energy relationships are still indispensable tools Thus pKa values1 are often used for

estimating relative nucleophilic reactivities and leaving group abilities (nucleofugalities) of certain species A

limitation of these so-called Broslashnsted correlations is the fact that pKa values refer to interactions with the

proton while most reactions considered involve formation or cleavage of bonds to carbon We have therefore

developed a Lewis basicity scale2 with respect to C-centered Lewis acids (carbocations and electron-poor p-

systems) and discuss their correlations with nucleophilicities3 and nucleofugalities Analogous relationships

between Lewis acidities electrophilicities and electrofugalities will also be reported4

1) For a comprehensive collection of pKa values see httpibondnankaieducn

2) Mayr H Ammer J Baidya M Maji B Nigst T A Ofial A R Singer T Am Chem Soc

2015 137 2580minus2599

3) For a collection of nucleophilicity and electrophilicity parameters see

httpwwwcuplmudeocmayrDBintrohtml

4) Mayr H Ofial A R Chem Res 2016 49 952ndash965

12

Pyroelectricity from Non-Polar Crystals Enables Understanding Features of

Crystal Growth and Design

Meir Lahav Elena Meirzadeh Eran Mishuk David Ehre Igor Lubomirsky

Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Pyroelectricity a property of certain crystalline materials is the creation of a temporary surface charge upon

temperature change resulting in an external electric current Thermal movement of the molecules alters their

average positions leading to changes in their dipole moments As a consequence of this property spontaneous

polarization was constricted to the polar directions of the ten polar crystal classes when exposed to temperature

change resulting in the creation of two oppositely charged faces which engender pyroelectricity With the

emergence of modern analytical instruments for measuring electric currents it became possible however to

probe the structures of polar defects and imperfections and near surface polar layers that outline non-polar

crystals In spite of their slight amounts those architectures play indispensible role for the understanding of the

different features that control the macroscopic properties of crystals and provide perceptiveness on the

mechanisms of crystal growth

The following sub-topics will be presented

a) Deciphering the riddle of polarity found in the growth of the centrosymmetric crystals of glycine1-2

b) Enantiomeric disorder within the crystals of DL alanine not detectable by diffraction3

c) Solvent molecules as ldquotailor-maderdquo auxiliary in the control of crystal polymorphism as illustrated with the

three polymorphs of glycine4

d) Pyroelectricity combined with theoretical simulations as a new analytical method for the structure

determination of polar tiny-doped domains in crystals at the molecular level5

(1) Meirzadeh E Sapir L et al JACS 2016 138 14756

(2) Piperno S et al Angew Chem Int Ed 2013 52 6513

(3) Mishuk E et al Cryst Growth Des 2014 14 3839

(4) Meirzadeh E Dishon S work in progress

(5) Meirzadeh E Azuri I et al Nature Com 2016 7 13354

13

Enantioselective Synthesis of Intrinsically Chiral Nanocrystals

Gil Markovich Assaf Ben Moshe Uri Hananel

School of Chemistry Tel Aviv University Tel Aviv Israel

We have recently shown that it is possible to perform an enantioselective synthesis of inorganic nanostructures

made of intrinsically chiral crystals such as a-HgS Te and Se These crystals belonging to the P3121 (or

P3221) chiral space group were grown as nanocrystals in the presence of thiolated chiral molecules such as

cysteine penicillamine or glutathione This led to a preference in the growth of the nanocrystals towards a

certain handedness and consequent strong optical activity

Furthermore in the case of Te nanostructures particular synthesis conditions led to overall chiral shape of the

elongated nanostructures expressed as a twist on the scale of the size of the nanostructures of the order of 100

nm Finally the Te could be easily converted to other materials such as gold or silver telluride while

preserving the chiral shape opening the way to the formation of strongly optically active nanostructures made

of various plasmonic or semiconductor materials

We now demonstrate enantioselective synthesis of another class of materials Lanthanide phosphate hydrate

nanocrystals (also of chiral space group) in the presence of tartaric acid The formed nanocrystals exhibit

substantial degree of circularly polarized luminescence and their enantiomeric excess depends non-linearly on

the enantiomeric excess of the tartaric acid ligands We believe that this system may be useful for studying the

mechanism of enantioselection of the formed nanocrystal seeds in the presence of the chiral molecules

14

Optical Microcavity Devices Containing Organic Materials

Yaakov R Tischler Department of Chemistry Bar-Ilan University Ramat-Gan Israel

When two dielectric mirrors are positioned closely together a half wavelength apart or an integer multiple

thereof they form a Fabry-Peacuterot resonator that can trap light of a specific wavelength for many optical cycles

This resonant light trapping phenomenon is at the heart of vertical cavity surface emitting lasers (VCSELs)

optical switches resonant cavity LEDs and numerous other photonic and optoelectronic devices When organic

materials are situated inside such photonic structures and stability issues are properly addressed amazing

results can be achieved such as strong light-matter coupling at room temperature in both the visible and

infrared (IR) spectral ranges low threshold lasing and super-radiant coupling between molecules Using

microcavities properly designed for use with organics here we show strong light-matter coupling in the mid-IR

spectral range and the first demonstration of a monolayer VCSEL where the gain layer consists of a thin film

of fluorescent dye that is one molecule thick We motivate possible sensor applications for these devices and

discuss the unique physical photochemical and photoelectrochemical processes that can be investigated in

such structures

15

Keynote Lecture

Stability Study of Cation Moieties in Alkaline Anion Exchange Membranes for

Fuel Cell Applications

Dario Dekel1 Charles E Diesendruck2 1Chemical Engineering Technion - Israel Institute of Technology Haifa Israel

2Chemistry Technion - Israel Institute of Technology Haifa Israel

There is an increasing worldwide interest in anion exchange membrane fuel cells (AEMFCs) due to the

potential of this technology to use low cost electrocatalysts promising a considerable cost reduction for new

generation of fuel cell devices However the stability of anion conducting polymers for durable anion exchange

membranes (AEMs) and anion exchange ionomers (AEIs) is still a great concern

Here we present a novel methodology to measure the true alkaline stability of anion conducting polymers to be

used in AEMFCs The new ex-situ technique simulates the environment of an AEMFC during operation where

nucleophilic and basic OH- species in the absence or with scarce amount of water attack the functional groups

of the ionic polymer Using this technique we clearly show the critical effect of water molecules on the alkaline

stability of quaternary ammonium (QA) cations commonly used as functional groups in AEMFCs

The results show that as the water content is reduced the QA cations are more rapidly degraded in the presence

of OH- at room temperature With increasing number of water molecules solvating the hydroxide its

nucleophilicity and basicity are hindered and the QA degradation is significantly slowed These results indicate

that the currently used aqueous alkali ex-situ tests to measure AEM stability may lead to false positive stability

results where anion conducting polymers may appear more alkali stable than they really are

We strongly recommend the adoption of this novel developed technique to measure the true stability of anion

conducting polymers to be used for AEMFCs We believe that this new ex-situ protocol will rapidly lead to

development and selection of best stable polymers for durable and robust AEMFCs

16

Probing the Electrode-Electrolyte Interface in Rechargeable Batteries by Solid

State NMR

Michal Leskes Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Reactions at the electrode-electrolyte interface in lithium ion batteries play a key role in the batteryrsquos

performance and are one of the main causes for cell failure These reactions which lead to the formation of the

solid electrolyte interphase (SEI) ultimately control the reversibility of the cellrsquos Li chemistry and its kinetics

Thus an important part in the development of new high energy storage materials is control over their interfacial

chemistry and reactivity with the electrolyte Nuclear magnetic resonance (NMR) spectroscopy is an excellent

approach for following the formation of interfacial layers as it can detect disordered and heterogeneous phases

providing information on their chemical composition structure and dynamic properties Its main disadvantage

is its low sensitivity which is often a limiting factor when probing the SEI Here Irsquoll describe approaches to

overcome this sensitivity limitation by isotope enrichment as well as the potential of new hyperpolarization

techniques which can provide detailed molecular level insight into the chemistry of the SEI

17

First-Principles Based Studies of Complex Oxide Materials

Ilya Grinberg Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Since their first discovery over 70 years ago complex ferroelectric oxides have been shown to exhibit a wide

variety of physical and chemical properties that enable their use in a broad range of applications In particular

the dynamics in a class of complex ferroelectric solid solutions known as relaxors have been under

investigation due to their glass-like behavior and excellent technological properties Nevertheless despite over

50 years of research the key bonding motifs of relaxor ferroelectrics that give rise to their fascinating properties

such as ultrahigh piezoelectric coefficients high permittivity over a broad temperature range diffuse phase

transition without macroscopic lattice symmetry strong frequency dependence in dielectric response and

phonon anomalies are still subject to debate We use molecular dynamics simulations for the prototypical

Pb(Mg13Nb23)O3-PbTiO3 relaxor material to examine the structure bonding and the spatial and temporal

correlations of relaxors Our simulations show that the unusual properties of relaxors simply stem from the

presence of a multidomain state with an extremely small asymp2-10 nm domain size and that dynamics of relaxors

exhibit striking similarities to those of water arising from the local-environment dependent dipole decoupling

due to chemical bonding variation at particular atomic sites

Ferroelectric materials have also recently attracted increased attention as a candidate class of materials for use

in photovoltaic devices In a series of computational studies of a variety of ferroelectric perovskite oxides we

showed that the physical behaviors of these materials are governed by the simple local structure and chemical

bonding characteristics these can then be modified to rationally design new materials with light absorption

through the visible range that enables the use of these materials in photovoltaic applications

18

Colorimetric Detection of the Early Stages of Aluminum Oxidation Using

Plasmonic Gold NanondashIsland Films

Alexander Tesler1 Eyal Sabatani3 Takumi Sannomiya4 Yishai Feldman2

Alexander Vaskevich1 Israel Rubinstein1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemistry Division Nuclear Research Centre Negev Beer-Sheva Israel

4Materials Science amp Engineering Tokyo Institute of Technology Yokohama Kanagawa

Japan

Corrosion is a natural process of degradation of metallic parts reacting with their environment and is the major

cause of failure of metal structures inndashservice Hence detection of the early stages of environmental oxidation

of metal parts is of great importance Here we present a colorimetric method for monitoring the surface

conditions of aluminum using the localized surface plasmon resonance (LSPR) response of gold nanoparticles

(NPs) prendashdeposited onto the aluminum surface Upon oxidation metallic aluminum transforms to transparent

dielectric aluminum oxide (or hydroxide) In water the formed oxidation product adopts a twondashlayer structure

the bottom layer is thinner and compact while the top layer is thicker and highly porous The gold nanondashisland

layer initially deposited (by evaporationannealing) on the aluminum surface maintains its integrity after

corrosion in water and is located between the two aluminum oxide layers Water oxidation of aluminum

substrates with an overlayer of plasmonic gold nano-islands leads to a pronounced color change which can be

monitored in situ using reflection spectroscopy or colorimetrically by the naked eye Theoretical calculations

show that the major spectral change during corrosion is attributed to the interplay between plasmonic scattering

of the Au NP layer reacting to the changing environment and interference within the bottom aluminum oxide

layer acting as an etalon sandwiched between the Au islands and the underlying aluminum The top porous

oxide layer has only a marginal contribution The results indicate that plasmonic gold NPs are well suited for

realndashtime monitoring of the corrosion kinetics of aluminum and its alloys in aqueous environment and in air

The technique is costndasheffective and can be carried out in the transmission or reflection configuration

19

Vertically Aligned Molybdenum Disulfide for Efficient Lithium Storage

Victor Shokhen1 Yana Miroshnikov1 Gregory Gershinsky1 Noam Gotlib2 Chen Stern2

Doron Naveh2 David Zitoun1 1Chemistry Nanotechnology and Advanced Materials (BINA) Bar-Ilan University

Ramat-Gan Israel 2Faculty of Engineering Bar-Ilan University Ramat-Gan Israel

Layered transition-metal disulfides (LTMDs) have played a prominent role in the development of electronic

energy conversion and storage devices Molybdenum disulfide (MoS2) has been widely investigated as a highly

efficient alternative to existing materials Most fabrication pathways of MoS2 focus on its planar growth on

various substrates to reach high-quality layers with planar orientation (PO) Nevertheless in most energy-

storage applications the most relevant orientation is the vertical alignment (VA) of well-defined layers VA

growth paves the way to highly dense devices with exposed active sites on the surface Here the chemical

vapor deposition (CVD) process has been investigated to grow 2H-MoS2 films hundreds of nanometers thick

with VA stacking The films show large domains of perfectly aligned layers with high crystallinity and density

and low surface roughness CVD-grown VA-MoS2 films show superior behavior in lithium storage with stable

capacity even at a high current density compared to PO-MoS2 films The VA-MoS2 films show a high

reversible capacity of 800 mAhg for lithium storage which corresponds to the full conversion to Mo and Li2S

HR-TEM images of VA-MoS2 Capacity of VA-MoS2 compare to PO-MoS2

20

Tailoring the Electronic Structure of TeY-doped NbBiO4 using Oxygen-

vacancy for All-oxide PV Application A Theoretical and Experimental Study

Vijay Singh Susanta Das David Keller Dan Thomas Major

Department of Chemistry Bar-Ilan University Ramat-Gan Israel

First principles studies of point defects and impurities in semiconductors insulators and metals have become an

integral part of material research over the last few decades1 Point defects and impurities often have decisive

effects on material properties2 3 Recently using density functional theory (DFT) calculations we have revealed

that Bi2O3 is a low band-gap material and the obtained energy band-gap 230 eV lies in the region of PV

interest The observed optical transitions between the valence band (VB) (O-2p states) and the conduction band

(CB) (Bi-6p states) are not allowed due to violation of the dipole selection rule (Δl =+-1) Therefore Bi2O3 is

not a potential absorber material for photovoltaic (PV) applications With the aid of DFT calculations and

experimental measurements we have also studied the NbBiO4 system extensively and our results revealed that

its valence band (VB) and conduction band (CB) consist of optically active states but its large energy band gap

350 eV puts a constraint on its use as an absorber material In the present talk I shall discuss how with the

help of suitable doping as well as oxygen vacancy we managed to reduce the energy band gap of NbBiO4 from

350 eV to 220 eV without changing its electronic structure The observed band-gap is in the region of PV

interest and transitions between the CB and VB states are optically allowed Using COHP (energy resolved

visualization of chemical bonding) calculations we revealed that Y doping in NbBiO4 significantly reduces the

covalent bonding between Bi and nearest neighbors oxygen ions from 100 eVbond to 010 eVbond As a

consequence the computed oxygen defect formation energies for Y-doped NbBiO4 system is lower than the

oxygen defect formation energies of the pure NbBiO4 system contributing to a large oxygen-defect

concentration Thus the significance of oxygen vacancy in Y-doped NbBiO4 (YBi site only) was revealed

and this study might serve to design better PV absorber materials in the future

References

1] Freysoldt C Grabowski B Hickel T Neugebauer J Kresse G Janotti A Van de Walle C G First-

principles calculations for point defects in solids Rev Mod Phys 2014 86 253-305

2] Ganguli N Dasgupta I Sanyal B Electronic structure and magnetism of transition metal doped Zn12O12

clusters Role of defects J Appl Phys 2010 108 123911

3] Yavo N Smith A D Yeheskel O Cohen S Korobko R Wachtel E Slater P R Lubomirsky I

Large Nonclassical Electrostriction in (Y Nb)‐ Stabilized δ‐ Bi2O3 Adv Funct Mater 2016

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

4

Keynote Lecture

Chemiluminescence Probes with Color Modulation

Doron Shabat Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Chemiluminescence is among the most sensitive methods for achieving a high signal-to-noise ratio in various

chemical and biological applications We have developed a modular practical synthetic route for preparation of

turn-ON dioxetane-tethered fluorophore chemiluminescent probes The chemiluminescent emission of the

probes was significantly amplified through energy transfer mechanism under physiological conditions Two

probes were composed of dioxetane tethered with green and near-infrared (NIR) fluorescent dyes While both

probes were able to provide chemiluminescence in vivo images following subcutaneous injection only the NIR

probe could provide chemiluminescence image following intraperitoneal injection These are the first in vivo

images produced by dioxetane-chemiluminescence probes with no addition of surfactant enhancer We

anticipate that our practical synthetic methodology will be useful for preparation of various chemiluminescent

probes for numerous applications

5

Selenocysteine Chemistry and Total Chemical Synthesis Applied for Accessing

Human Selenoproteins

Norman Metanis Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Once considered a toxic element selenium is now known as an essential element for life For example in

humans it is incorporated in proteins known as selenoproteins containing the 21st encoded amino acid

selenocysteine (Sec) The differences between selenium and sulfur in their redox potentials pKas and

nucleophilicities and electrophilicities give selenium interesting chemistry For example Sec can be used as a

tool for chemical protein synthesis and allowing for site selective modifications It can be also incorporated

into protein sequences to enhance oxidative protein folding This lecture will discuss our recent studies on

chemical protein synthesis using Sec and selective deselenization reactions which convert Sec into Ala or Ser

These advances in chemical protein synthesis bring us closer to accessing naturally occurring selenoproteins

especially human selenoproteins that still await functional characterization

6

Olrsquo Bimane is Learning New Tricks

Flavio Grynszpan1 Partha J Das1 Ankana Roy1 Yael Diskin-Posner2 Iddo Pinkas2

Michael Firer3 Michael Montag1 1Chemical Sciences Ariel University Ariel Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemical Engineering and Biotechnology Ariel University Ariel Israel

Bimanes are hetero-bicyclic molecules that can be readily synthesized in moderate to good yields These low

molecular weight fluorophores were developed by Prof E Kosower and co-workers about 40 years ago[i]

From the two possible diastereomeric forms only syn-bimanes are strongly fluorescent Some bimane

derivatives have become useful as fluorescent probes for different applications ranging from biological labeling

to LASER dyes Recently we showed that when attached to an appropriate carrier moiety syn-bimane can

cross the blood-brain-barrier (BBB) of living mice and be clearly detected in brain tissue[ii] syn-Bimanes

present an N-imide structure as an integral part of their skeleton which in the past was never exploited as a

metal binding motif We showed that a cationic Pd(II) complex (2) containing syn-(MeMe)bimane (1 R1-4 =

Me) as a ligand could be prepared and was fully characterized[iii] We are currently involved in the preparation

of bimane derivatives where the oxygen atoms are replaced by sulfur atoms The novel mono- and di-thioxo-

bimanes are expected to display novel spectroscopic properties and give rise to more stable complexes with

different metals Our latest results with oxo- and thioxo-bimanes their structures chemistry and spectroscopic

studies will be presented

[i] E M Kosower B Pazhenchevsky E Hershkowitz J Am Chem Soc 1978 100 6516

[ii] I Lapidot D Baranes A Pinhasov G Gellerman A Albeck F Grynszpan S E Shatzmiller Med

Chem 2016 12 48

[iii] PJ Das Y Diskin-Posner M Firer M Montag F Grynszpan Dalton Trans 201645 17123-17131

7

Synthesis of Highly Functionalized Alkenylfluorides by Silver-Mediated

Fluorodestannation

Heiko Sommer12 Alois Fuumlrstner1 1Organometallic Chemistry Max-Planck-Institut fuumlr Kohlenforschung Muumllheim an der Ruhr

Germany 2Schulich Faculty of Chemistry Technion - Israel Institute of Technology Haifa Israel

The role of fluorine in synthetic and medicinal chemistry receives an ever-increasing attention as fluorine plays

a unique role in influencing the conformation solubility potency permeability or degradability of small

molecules The late-stage introduction of fluorine is of great interest as it allows the modification of complex

molecules without significantly changing the synthetic route

In conjunction with our previously reported ruthenium-catalyzed directed trans-hydrostannation of internal

alkynes[1] an efficient method for the synthesis of highly elaborate alkenyl fluorides could be implemented

(Scheme 1)[2]

Scheme 1 Hydrostannationfluorodestannation for the synthesis of fluoroolefins

During our studies we developed a mild protocol that allowed us to transform a plethora of alkenylstannanes

into the corresponding fluorides while overcoming competing protodestannation[3] Key to success is the

utilization of the non-hygroscopic salt silver(I) diphenyl phosphinate (AgDPP) as a mediator

We applied this new protocol to the synthesis of highly functionalized biologically relevant compounds

consisting among others of a polyketide derivative a peptide bioisoster and a prostaglandin derivative (Scheme

2)

Scheme 2 Selected examples of the silver-mediated fluorodestannation

Literature

[1] a) S M Rummelt A Fuumlrstner Angew Chem Int Ed 2014 53 3626-3630 b) S M Rummelt K

Radkowski D-A Roşca A Fuumlrstner J Am Chem Soc 2015 137 5506-5519

[2] H Sommer A Fuumlrstner submitted manuscript 2016

[3] M A Tius J K Kawakami Tetrahedron 1995 51 3997-4010

8

Stimuli-responsive Self-immolative Chemiluminescent Polymers

Samer Gnaim Doron Shabat

Organic Chemistry Tel Aviv University Tel Aviv Israel

Molecular probes based on 3-hydroxyphenyl-12-dioxetane chemiluminescence light emission are widely used

for various sensing and diagnostic applications (eg DNA enzymatic and chemical probes) Amplification of

molecular signals is an important task for the development of sensitive diagnostic probes in the field of

chemical sensing Recently various approaches have been introduced to increase the signal-to-noise ratio of

chemiluminescent light emission as a molecular signal

This work describes the design and synthesis of a new class of self-immolative chemiluminescent polymers

constructed of four complementary components ) chemically stable 12-dioxatene analog incorporated an

adamantyl group (bulky substituent) ii) protected 4-hydroxybenzyl alcohol substituent (self-immolative

monomeric linker) iii) a chemical or biological responsive group (eg silyl protecting group) and iv) the

monomers are linked together via carbonate linkage

Our results show that a single cleavage event of the protecting group on the phenol results in the formation of a

quinone derivative of 12-dioxetane which undergoes a rapid 16-elimination to release the leaving group on

the benzyl alcohol A nucleophilic attack on the benzylic-methide position initiates a chemically initiated

electron-exchange luminescence (CIEEL) process affording methyl benzoate and light emission

Using this new class of chemiluminescent polymers introduce the ability to design a novel stimuli responsive

chemilumnescent polymers as an amplification systems

9

Synthesis and Evaluation of NPP1 Inhibitors as Potential Drugs for the

Treatment of OsteoarthritisCPPD Disease

Molhm Nassir1 Shani Journo2 Abed Saady1 Uri Arad2 Bilha Fischer1 1Department of Chemistry Bar-Ilan University Ramat-Gan Israel

2Department of Rheumatology Tel Aviv Medical Center and the Faculty of Medicine Tel Aviv

Israel

Overproduction of extracellular pyrophosphate due to hydrolysis of ATP by NPP1 leads to deposition of

pathological Ca2P2O7H2O (CPPD) in cartilage resulting in a degenerative joint disease (CPPD disease) which

has no cure We explored the hypothesis that NPP1 inhibitors may be therapeutic agents for CPPD disease by

inhibiting the hydrolysis of ATP Specifically we synthesized novel analogs of ADP (an NPP1 substrate) in

which the Pab bridging oxygen atom is replaced by a methylene group and a derivative where both Pab

phosphate groups are replaced by sulfonate groups 1 and the Pb phosphate is replaced by a sulfonate isoster 2

In addition we synthesized an ADP analog in which the ribose ring was cleaved and the primary alcohol was

substituted by bis-phosphonate 3 To predict the ability of the derivatives to inhibit NPP1 we evaluated the

affinity and selectivity of the analogs to Zn2+ involved in NPP1rsquos catalytic activity We titrated the analogs with

Zn2+- or Ca2+ ions and monitored the titrations by UV Analogs 1 and 2 selectively coordinated Zn2+ and not

Ca2+ and formed ZnL2 complexes whereas analog 3 showed no affinity for Zn2+ and Ca2+ ions Next analogs

1 2 and 3 have been evaluated for their inhibitory effect on NPP1 in human chondrocytes Analog 3 proved to

be a promising inhibitor reducing NPPase activity in human chondrocytes by 90 at 100 microM vs analogs 1

and 2 (40 and 30 inhibition at 100 microM) Analogs 1 2 and 3 were found to be NPP selective showing no

activity at TNAP In summary analog 3 was found to be an effective and selective NPP1 inhibitor in human

chondrocytes Since analog 3 is a poor Zn2+-chelator we hypothesize that its inhibitory effect may be related to

its high flexibility at NPP1rsquos catalytic site

10

Evaluating the Peptide Structure Prediction Capabilities of a Purely Ab-Initio

Method

Moshe Goldstein13 Moshe Amitay2 1Department of Computer Science Jerusalem College of Technology Jerusalem Israel

2Department of Bioinformatics Jerusalem College of Technology Jerusalem Israel 3The Fritz Haber Research Center The Hebrew University of Jerusalem Jerusalem Israel

Peptides such as hormones and antibiotics play many biological functions Peptides` tertiary structures are of

paramount importance for understanding their function as well as the interactions with other molecules

DEEPSAM[1] (Diffusion Equation Evolutionary Programming Simulated Annealing Method) is a novel purely

ab-initio global optimization algorithm aimed to predict the structure of peptides and proteins from amino acid

sequence without any preliminary assumption This method is an Evolutionary Programming algorithm whose

mutation operators are built by hybridizing the advantages of three well-known optimization methods -

Diffusion Equation Method (DEM) Molecular Dynamics Simulated Annealing (MDSA) and the BFGS quasi-

Newton local minimization method

In principle DEEPSAM requires much less computing resources and is much faster than other structure

prediction methods such as Replica Exchange Molecular Dynamics (REMD) and therefore seems to be more

suitable for industrial use

The goal of this study has been to further evaluate the structure prediction accuracy of the DEEPSAM

algorithm by running it against a large number of known NMR structures of linear peptides (10-20 residues) in

an aqueous environment modeled by the GBSA implicit solvent model

[1] M Goldstein E Fredj and R B Gerber A New Hybrid Algorithm for Finding the Lowest Minima of

Potential Surfaces Approach and Applications to Peptides J of Computational Chemistry vol 32 pp 1785ndash

1800 (2011)

11

Keynote Lecture

Quantification of Polar Organic Reactivity

Herbert Mayr Department of Chemistry Ludwig-Maximilian-University Munich Muenchen Germany

The precision of quantum chemical calculations has reached a level that they can predict the thermodynamics of

organic reactions in the gas phase with an accuracy sometimes even exceeding that of experimental methods In

contrast calculations of reaction pathways in solution are still rather laborious and are predominantly used for

investigating mechanisms of known reactions rather than for designing new synthetic transformations For the

latter purpose linear free energy relationships are still indispensable tools Thus pKa values1 are often used for

estimating relative nucleophilic reactivities and leaving group abilities (nucleofugalities) of certain species A

limitation of these so-called Broslashnsted correlations is the fact that pKa values refer to interactions with the

proton while most reactions considered involve formation or cleavage of bonds to carbon We have therefore

developed a Lewis basicity scale2 with respect to C-centered Lewis acids (carbocations and electron-poor p-

systems) and discuss their correlations with nucleophilicities3 and nucleofugalities Analogous relationships

between Lewis acidities electrophilicities and electrofugalities will also be reported4

1) For a comprehensive collection of pKa values see httpibondnankaieducn

2) Mayr H Ammer J Baidya M Maji B Nigst T A Ofial A R Singer T Am Chem Soc

2015 137 2580minus2599

3) For a collection of nucleophilicity and electrophilicity parameters see

httpwwwcuplmudeocmayrDBintrohtml

4) Mayr H Ofial A R Chem Res 2016 49 952ndash965

12

Pyroelectricity from Non-Polar Crystals Enables Understanding Features of

Crystal Growth and Design

Meir Lahav Elena Meirzadeh Eran Mishuk David Ehre Igor Lubomirsky

Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Pyroelectricity a property of certain crystalline materials is the creation of a temporary surface charge upon

temperature change resulting in an external electric current Thermal movement of the molecules alters their

average positions leading to changes in their dipole moments As a consequence of this property spontaneous

polarization was constricted to the polar directions of the ten polar crystal classes when exposed to temperature

change resulting in the creation of two oppositely charged faces which engender pyroelectricity With the

emergence of modern analytical instruments for measuring electric currents it became possible however to

probe the structures of polar defects and imperfections and near surface polar layers that outline non-polar

crystals In spite of their slight amounts those architectures play indispensible role for the understanding of the

different features that control the macroscopic properties of crystals and provide perceptiveness on the

mechanisms of crystal growth

The following sub-topics will be presented

a) Deciphering the riddle of polarity found in the growth of the centrosymmetric crystals of glycine1-2

b) Enantiomeric disorder within the crystals of DL alanine not detectable by diffraction3

c) Solvent molecules as ldquotailor-maderdquo auxiliary in the control of crystal polymorphism as illustrated with the

three polymorphs of glycine4

d) Pyroelectricity combined with theoretical simulations as a new analytical method for the structure

determination of polar tiny-doped domains in crystals at the molecular level5

(1) Meirzadeh E Sapir L et al JACS 2016 138 14756

(2) Piperno S et al Angew Chem Int Ed 2013 52 6513

(3) Mishuk E et al Cryst Growth Des 2014 14 3839

(4) Meirzadeh E Dishon S work in progress

(5) Meirzadeh E Azuri I et al Nature Com 2016 7 13354

13

Enantioselective Synthesis of Intrinsically Chiral Nanocrystals

Gil Markovich Assaf Ben Moshe Uri Hananel

School of Chemistry Tel Aviv University Tel Aviv Israel

We have recently shown that it is possible to perform an enantioselective synthesis of inorganic nanostructures

made of intrinsically chiral crystals such as a-HgS Te and Se These crystals belonging to the P3121 (or

P3221) chiral space group were grown as nanocrystals in the presence of thiolated chiral molecules such as

cysteine penicillamine or glutathione This led to a preference in the growth of the nanocrystals towards a

certain handedness and consequent strong optical activity

Furthermore in the case of Te nanostructures particular synthesis conditions led to overall chiral shape of the

elongated nanostructures expressed as a twist on the scale of the size of the nanostructures of the order of 100

nm Finally the Te could be easily converted to other materials such as gold or silver telluride while

preserving the chiral shape opening the way to the formation of strongly optically active nanostructures made

of various plasmonic or semiconductor materials

We now demonstrate enantioselective synthesis of another class of materials Lanthanide phosphate hydrate

nanocrystals (also of chiral space group) in the presence of tartaric acid The formed nanocrystals exhibit

substantial degree of circularly polarized luminescence and their enantiomeric excess depends non-linearly on

the enantiomeric excess of the tartaric acid ligands We believe that this system may be useful for studying the

mechanism of enantioselection of the formed nanocrystal seeds in the presence of the chiral molecules

14

Optical Microcavity Devices Containing Organic Materials

Yaakov R Tischler Department of Chemistry Bar-Ilan University Ramat-Gan Israel

When two dielectric mirrors are positioned closely together a half wavelength apart or an integer multiple

thereof they form a Fabry-Peacuterot resonator that can trap light of a specific wavelength for many optical cycles

This resonant light trapping phenomenon is at the heart of vertical cavity surface emitting lasers (VCSELs)

optical switches resonant cavity LEDs and numerous other photonic and optoelectronic devices When organic

materials are situated inside such photonic structures and stability issues are properly addressed amazing

results can be achieved such as strong light-matter coupling at room temperature in both the visible and

infrared (IR) spectral ranges low threshold lasing and super-radiant coupling between molecules Using

microcavities properly designed for use with organics here we show strong light-matter coupling in the mid-IR

spectral range and the first demonstration of a monolayer VCSEL where the gain layer consists of a thin film

of fluorescent dye that is one molecule thick We motivate possible sensor applications for these devices and

discuss the unique physical photochemical and photoelectrochemical processes that can be investigated in

such structures

15

Keynote Lecture

Stability Study of Cation Moieties in Alkaline Anion Exchange Membranes for

Fuel Cell Applications

Dario Dekel1 Charles E Diesendruck2 1Chemical Engineering Technion - Israel Institute of Technology Haifa Israel

2Chemistry Technion - Israel Institute of Technology Haifa Israel

There is an increasing worldwide interest in anion exchange membrane fuel cells (AEMFCs) due to the

potential of this technology to use low cost electrocatalysts promising a considerable cost reduction for new

generation of fuel cell devices However the stability of anion conducting polymers for durable anion exchange

membranes (AEMs) and anion exchange ionomers (AEIs) is still a great concern

Here we present a novel methodology to measure the true alkaline stability of anion conducting polymers to be

used in AEMFCs The new ex-situ technique simulates the environment of an AEMFC during operation where

nucleophilic and basic OH- species in the absence or with scarce amount of water attack the functional groups

of the ionic polymer Using this technique we clearly show the critical effect of water molecules on the alkaline

stability of quaternary ammonium (QA) cations commonly used as functional groups in AEMFCs

The results show that as the water content is reduced the QA cations are more rapidly degraded in the presence

of OH- at room temperature With increasing number of water molecules solvating the hydroxide its

nucleophilicity and basicity are hindered and the QA degradation is significantly slowed These results indicate

that the currently used aqueous alkali ex-situ tests to measure AEM stability may lead to false positive stability

results where anion conducting polymers may appear more alkali stable than they really are

We strongly recommend the adoption of this novel developed technique to measure the true stability of anion

conducting polymers to be used for AEMFCs We believe that this new ex-situ protocol will rapidly lead to

development and selection of best stable polymers for durable and robust AEMFCs

16

Probing the Electrode-Electrolyte Interface in Rechargeable Batteries by Solid

State NMR

Michal Leskes Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Reactions at the electrode-electrolyte interface in lithium ion batteries play a key role in the batteryrsquos

performance and are one of the main causes for cell failure These reactions which lead to the formation of the

solid electrolyte interphase (SEI) ultimately control the reversibility of the cellrsquos Li chemistry and its kinetics

Thus an important part in the development of new high energy storage materials is control over their interfacial

chemistry and reactivity with the electrolyte Nuclear magnetic resonance (NMR) spectroscopy is an excellent

approach for following the formation of interfacial layers as it can detect disordered and heterogeneous phases

providing information on their chemical composition structure and dynamic properties Its main disadvantage

is its low sensitivity which is often a limiting factor when probing the SEI Here Irsquoll describe approaches to

overcome this sensitivity limitation by isotope enrichment as well as the potential of new hyperpolarization

techniques which can provide detailed molecular level insight into the chemistry of the SEI

17

First-Principles Based Studies of Complex Oxide Materials

Ilya Grinberg Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Since their first discovery over 70 years ago complex ferroelectric oxides have been shown to exhibit a wide

variety of physical and chemical properties that enable their use in a broad range of applications In particular

the dynamics in a class of complex ferroelectric solid solutions known as relaxors have been under

investigation due to their glass-like behavior and excellent technological properties Nevertheless despite over

50 years of research the key bonding motifs of relaxor ferroelectrics that give rise to their fascinating properties

such as ultrahigh piezoelectric coefficients high permittivity over a broad temperature range diffuse phase

transition without macroscopic lattice symmetry strong frequency dependence in dielectric response and

phonon anomalies are still subject to debate We use molecular dynamics simulations for the prototypical

Pb(Mg13Nb23)O3-PbTiO3 relaxor material to examine the structure bonding and the spatial and temporal

correlations of relaxors Our simulations show that the unusual properties of relaxors simply stem from the

presence of a multidomain state with an extremely small asymp2-10 nm domain size and that dynamics of relaxors

exhibit striking similarities to those of water arising from the local-environment dependent dipole decoupling

due to chemical bonding variation at particular atomic sites

Ferroelectric materials have also recently attracted increased attention as a candidate class of materials for use

in photovoltaic devices In a series of computational studies of a variety of ferroelectric perovskite oxides we

showed that the physical behaviors of these materials are governed by the simple local structure and chemical

bonding characteristics these can then be modified to rationally design new materials with light absorption

through the visible range that enables the use of these materials in photovoltaic applications

18

Colorimetric Detection of the Early Stages of Aluminum Oxidation Using

Plasmonic Gold NanondashIsland Films

Alexander Tesler1 Eyal Sabatani3 Takumi Sannomiya4 Yishai Feldman2

Alexander Vaskevich1 Israel Rubinstein1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemistry Division Nuclear Research Centre Negev Beer-Sheva Israel

4Materials Science amp Engineering Tokyo Institute of Technology Yokohama Kanagawa

Japan

Corrosion is a natural process of degradation of metallic parts reacting with their environment and is the major

cause of failure of metal structures inndashservice Hence detection of the early stages of environmental oxidation

of metal parts is of great importance Here we present a colorimetric method for monitoring the surface

conditions of aluminum using the localized surface plasmon resonance (LSPR) response of gold nanoparticles

(NPs) prendashdeposited onto the aluminum surface Upon oxidation metallic aluminum transforms to transparent

dielectric aluminum oxide (or hydroxide) In water the formed oxidation product adopts a twondashlayer structure

the bottom layer is thinner and compact while the top layer is thicker and highly porous The gold nanondashisland

layer initially deposited (by evaporationannealing) on the aluminum surface maintains its integrity after

corrosion in water and is located between the two aluminum oxide layers Water oxidation of aluminum

substrates with an overlayer of plasmonic gold nano-islands leads to a pronounced color change which can be

monitored in situ using reflection spectroscopy or colorimetrically by the naked eye Theoretical calculations

show that the major spectral change during corrosion is attributed to the interplay between plasmonic scattering

of the Au NP layer reacting to the changing environment and interference within the bottom aluminum oxide

layer acting as an etalon sandwiched between the Au islands and the underlying aluminum The top porous

oxide layer has only a marginal contribution The results indicate that plasmonic gold NPs are well suited for

realndashtime monitoring of the corrosion kinetics of aluminum and its alloys in aqueous environment and in air

The technique is costndasheffective and can be carried out in the transmission or reflection configuration

19

Vertically Aligned Molybdenum Disulfide for Efficient Lithium Storage

Victor Shokhen1 Yana Miroshnikov1 Gregory Gershinsky1 Noam Gotlib2 Chen Stern2

Doron Naveh2 David Zitoun1 1Chemistry Nanotechnology and Advanced Materials (BINA) Bar-Ilan University

Ramat-Gan Israel 2Faculty of Engineering Bar-Ilan University Ramat-Gan Israel

Layered transition-metal disulfides (LTMDs) have played a prominent role in the development of electronic

energy conversion and storage devices Molybdenum disulfide (MoS2) has been widely investigated as a highly

efficient alternative to existing materials Most fabrication pathways of MoS2 focus on its planar growth on

various substrates to reach high-quality layers with planar orientation (PO) Nevertheless in most energy-

storage applications the most relevant orientation is the vertical alignment (VA) of well-defined layers VA

growth paves the way to highly dense devices with exposed active sites on the surface Here the chemical

vapor deposition (CVD) process has been investigated to grow 2H-MoS2 films hundreds of nanometers thick

with VA stacking The films show large domains of perfectly aligned layers with high crystallinity and density

and low surface roughness CVD-grown VA-MoS2 films show superior behavior in lithium storage with stable

capacity even at a high current density compared to PO-MoS2 films The VA-MoS2 films show a high

reversible capacity of 800 mAhg for lithium storage which corresponds to the full conversion to Mo and Li2S

HR-TEM images of VA-MoS2 Capacity of VA-MoS2 compare to PO-MoS2

20

Tailoring the Electronic Structure of TeY-doped NbBiO4 using Oxygen-

vacancy for All-oxide PV Application A Theoretical and Experimental Study

Vijay Singh Susanta Das David Keller Dan Thomas Major

Department of Chemistry Bar-Ilan University Ramat-Gan Israel

First principles studies of point defects and impurities in semiconductors insulators and metals have become an

integral part of material research over the last few decades1 Point defects and impurities often have decisive

effects on material properties2 3 Recently using density functional theory (DFT) calculations we have revealed

that Bi2O3 is a low band-gap material and the obtained energy band-gap 230 eV lies in the region of PV

interest The observed optical transitions between the valence band (VB) (O-2p states) and the conduction band

(CB) (Bi-6p states) are not allowed due to violation of the dipole selection rule (Δl =+-1) Therefore Bi2O3 is

not a potential absorber material for photovoltaic (PV) applications With the aid of DFT calculations and

experimental measurements we have also studied the NbBiO4 system extensively and our results revealed that

its valence band (VB) and conduction band (CB) consist of optically active states but its large energy band gap

350 eV puts a constraint on its use as an absorber material In the present talk I shall discuss how with the

help of suitable doping as well as oxygen vacancy we managed to reduce the energy band gap of NbBiO4 from

350 eV to 220 eV without changing its electronic structure The observed band-gap is in the region of PV

interest and transitions between the CB and VB states are optically allowed Using COHP (energy resolved

visualization of chemical bonding) calculations we revealed that Y doping in NbBiO4 significantly reduces the

covalent bonding between Bi and nearest neighbors oxygen ions from 100 eVbond to 010 eVbond As a

consequence the computed oxygen defect formation energies for Y-doped NbBiO4 system is lower than the

oxygen defect formation energies of the pure NbBiO4 system contributing to a large oxygen-defect

concentration Thus the significance of oxygen vacancy in Y-doped NbBiO4 (YBi site only) was revealed

and this study might serve to design better PV absorber materials in the future

References

1] Freysoldt C Grabowski B Hickel T Neugebauer J Kresse G Janotti A Van de Walle C G First-

principles calculations for point defects in solids Rev Mod Phys 2014 86 253-305

2] Ganguli N Dasgupta I Sanyal B Electronic structure and magnetism of transition metal doped Zn12O12

clusters Role of defects J Appl Phys 2010 108 123911

3] Yavo N Smith A D Yeheskel O Cohen S Korobko R Wachtel E Slater P R Lubomirsky I

Large Nonclassical Electrostriction in (Y Nb)‐ Stabilized δ‐ Bi2O3 Adv Funct Mater 2016

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

5

Selenocysteine Chemistry and Total Chemical Synthesis Applied for Accessing

Human Selenoproteins

Norman Metanis Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Once considered a toxic element selenium is now known as an essential element for life For example in

humans it is incorporated in proteins known as selenoproteins containing the 21st encoded amino acid

selenocysteine (Sec) The differences between selenium and sulfur in their redox potentials pKas and

nucleophilicities and electrophilicities give selenium interesting chemistry For example Sec can be used as a

tool for chemical protein synthesis and allowing for site selective modifications It can be also incorporated

into protein sequences to enhance oxidative protein folding This lecture will discuss our recent studies on

chemical protein synthesis using Sec and selective deselenization reactions which convert Sec into Ala or Ser

These advances in chemical protein synthesis bring us closer to accessing naturally occurring selenoproteins

especially human selenoproteins that still await functional characterization

6

Olrsquo Bimane is Learning New Tricks

Flavio Grynszpan1 Partha J Das1 Ankana Roy1 Yael Diskin-Posner2 Iddo Pinkas2

Michael Firer3 Michael Montag1 1Chemical Sciences Ariel University Ariel Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemical Engineering and Biotechnology Ariel University Ariel Israel

Bimanes are hetero-bicyclic molecules that can be readily synthesized in moderate to good yields These low

molecular weight fluorophores were developed by Prof E Kosower and co-workers about 40 years ago[i]

From the two possible diastereomeric forms only syn-bimanes are strongly fluorescent Some bimane

derivatives have become useful as fluorescent probes for different applications ranging from biological labeling

to LASER dyes Recently we showed that when attached to an appropriate carrier moiety syn-bimane can

cross the blood-brain-barrier (BBB) of living mice and be clearly detected in brain tissue[ii] syn-Bimanes

present an N-imide structure as an integral part of their skeleton which in the past was never exploited as a

metal binding motif We showed that a cationic Pd(II) complex (2) containing syn-(MeMe)bimane (1 R1-4 =

Me) as a ligand could be prepared and was fully characterized[iii] We are currently involved in the preparation

of bimane derivatives where the oxygen atoms are replaced by sulfur atoms The novel mono- and di-thioxo-

bimanes are expected to display novel spectroscopic properties and give rise to more stable complexes with

different metals Our latest results with oxo- and thioxo-bimanes their structures chemistry and spectroscopic

studies will be presented

[i] E M Kosower B Pazhenchevsky E Hershkowitz J Am Chem Soc 1978 100 6516

[ii] I Lapidot D Baranes A Pinhasov G Gellerman A Albeck F Grynszpan S E Shatzmiller Med

Chem 2016 12 48

[iii] PJ Das Y Diskin-Posner M Firer M Montag F Grynszpan Dalton Trans 201645 17123-17131

7

Synthesis of Highly Functionalized Alkenylfluorides by Silver-Mediated

Fluorodestannation

Heiko Sommer12 Alois Fuumlrstner1 1Organometallic Chemistry Max-Planck-Institut fuumlr Kohlenforschung Muumllheim an der Ruhr

Germany 2Schulich Faculty of Chemistry Technion - Israel Institute of Technology Haifa Israel

The role of fluorine in synthetic and medicinal chemistry receives an ever-increasing attention as fluorine plays

a unique role in influencing the conformation solubility potency permeability or degradability of small

molecules The late-stage introduction of fluorine is of great interest as it allows the modification of complex

molecules without significantly changing the synthetic route

In conjunction with our previously reported ruthenium-catalyzed directed trans-hydrostannation of internal

alkynes[1] an efficient method for the synthesis of highly elaborate alkenyl fluorides could be implemented

(Scheme 1)[2]

Scheme 1 Hydrostannationfluorodestannation for the synthesis of fluoroolefins

During our studies we developed a mild protocol that allowed us to transform a plethora of alkenylstannanes

into the corresponding fluorides while overcoming competing protodestannation[3] Key to success is the

utilization of the non-hygroscopic salt silver(I) diphenyl phosphinate (AgDPP) as a mediator

We applied this new protocol to the synthesis of highly functionalized biologically relevant compounds

consisting among others of a polyketide derivative a peptide bioisoster and a prostaglandin derivative (Scheme

2)

Scheme 2 Selected examples of the silver-mediated fluorodestannation

Literature

[1] a) S M Rummelt A Fuumlrstner Angew Chem Int Ed 2014 53 3626-3630 b) S M Rummelt K

Radkowski D-A Roşca A Fuumlrstner J Am Chem Soc 2015 137 5506-5519

[2] H Sommer A Fuumlrstner submitted manuscript 2016

[3] M A Tius J K Kawakami Tetrahedron 1995 51 3997-4010

8

Stimuli-responsive Self-immolative Chemiluminescent Polymers

Samer Gnaim Doron Shabat

Organic Chemistry Tel Aviv University Tel Aviv Israel

Molecular probes based on 3-hydroxyphenyl-12-dioxetane chemiluminescence light emission are widely used

for various sensing and diagnostic applications (eg DNA enzymatic and chemical probes) Amplification of

molecular signals is an important task for the development of sensitive diagnostic probes in the field of

chemical sensing Recently various approaches have been introduced to increase the signal-to-noise ratio of

chemiluminescent light emission as a molecular signal

This work describes the design and synthesis of a new class of self-immolative chemiluminescent polymers

constructed of four complementary components ) chemically stable 12-dioxatene analog incorporated an

adamantyl group (bulky substituent) ii) protected 4-hydroxybenzyl alcohol substituent (self-immolative

monomeric linker) iii) a chemical or biological responsive group (eg silyl protecting group) and iv) the

monomers are linked together via carbonate linkage

Our results show that a single cleavage event of the protecting group on the phenol results in the formation of a

quinone derivative of 12-dioxetane which undergoes a rapid 16-elimination to release the leaving group on

the benzyl alcohol A nucleophilic attack on the benzylic-methide position initiates a chemically initiated

electron-exchange luminescence (CIEEL) process affording methyl benzoate and light emission

Using this new class of chemiluminescent polymers introduce the ability to design a novel stimuli responsive

chemilumnescent polymers as an amplification systems

9

Synthesis and Evaluation of NPP1 Inhibitors as Potential Drugs for the

Treatment of OsteoarthritisCPPD Disease

Molhm Nassir1 Shani Journo2 Abed Saady1 Uri Arad2 Bilha Fischer1 1Department of Chemistry Bar-Ilan University Ramat-Gan Israel

2Department of Rheumatology Tel Aviv Medical Center and the Faculty of Medicine Tel Aviv

Israel

Overproduction of extracellular pyrophosphate due to hydrolysis of ATP by NPP1 leads to deposition of

pathological Ca2P2O7H2O (CPPD) in cartilage resulting in a degenerative joint disease (CPPD disease) which

has no cure We explored the hypothesis that NPP1 inhibitors may be therapeutic agents for CPPD disease by

inhibiting the hydrolysis of ATP Specifically we synthesized novel analogs of ADP (an NPP1 substrate) in

which the Pab bridging oxygen atom is replaced by a methylene group and a derivative where both Pab

phosphate groups are replaced by sulfonate groups 1 and the Pb phosphate is replaced by a sulfonate isoster 2

In addition we synthesized an ADP analog in which the ribose ring was cleaved and the primary alcohol was

substituted by bis-phosphonate 3 To predict the ability of the derivatives to inhibit NPP1 we evaluated the

affinity and selectivity of the analogs to Zn2+ involved in NPP1rsquos catalytic activity We titrated the analogs with

Zn2+- or Ca2+ ions and monitored the titrations by UV Analogs 1 and 2 selectively coordinated Zn2+ and not

Ca2+ and formed ZnL2 complexes whereas analog 3 showed no affinity for Zn2+ and Ca2+ ions Next analogs

1 2 and 3 have been evaluated for their inhibitory effect on NPP1 in human chondrocytes Analog 3 proved to

be a promising inhibitor reducing NPPase activity in human chondrocytes by 90 at 100 microM vs analogs 1

and 2 (40 and 30 inhibition at 100 microM) Analogs 1 2 and 3 were found to be NPP selective showing no

activity at TNAP In summary analog 3 was found to be an effective and selective NPP1 inhibitor in human

chondrocytes Since analog 3 is a poor Zn2+-chelator we hypothesize that its inhibitory effect may be related to

its high flexibility at NPP1rsquos catalytic site

10

Evaluating the Peptide Structure Prediction Capabilities of a Purely Ab-Initio

Method

Moshe Goldstein13 Moshe Amitay2 1Department of Computer Science Jerusalem College of Technology Jerusalem Israel

2Department of Bioinformatics Jerusalem College of Technology Jerusalem Israel 3The Fritz Haber Research Center The Hebrew University of Jerusalem Jerusalem Israel

Peptides such as hormones and antibiotics play many biological functions Peptides` tertiary structures are of

paramount importance for understanding their function as well as the interactions with other molecules

DEEPSAM[1] (Diffusion Equation Evolutionary Programming Simulated Annealing Method) is a novel purely

ab-initio global optimization algorithm aimed to predict the structure of peptides and proteins from amino acid

sequence without any preliminary assumption This method is an Evolutionary Programming algorithm whose

mutation operators are built by hybridizing the advantages of three well-known optimization methods -

Diffusion Equation Method (DEM) Molecular Dynamics Simulated Annealing (MDSA) and the BFGS quasi-

Newton local minimization method

In principle DEEPSAM requires much less computing resources and is much faster than other structure

prediction methods such as Replica Exchange Molecular Dynamics (REMD) and therefore seems to be more

suitable for industrial use

The goal of this study has been to further evaluate the structure prediction accuracy of the DEEPSAM

algorithm by running it against a large number of known NMR structures of linear peptides (10-20 residues) in

an aqueous environment modeled by the GBSA implicit solvent model

[1] M Goldstein E Fredj and R B Gerber A New Hybrid Algorithm for Finding the Lowest Minima of

Potential Surfaces Approach and Applications to Peptides J of Computational Chemistry vol 32 pp 1785ndash

1800 (2011)

11

Keynote Lecture

Quantification of Polar Organic Reactivity

Herbert Mayr Department of Chemistry Ludwig-Maximilian-University Munich Muenchen Germany

The precision of quantum chemical calculations has reached a level that they can predict the thermodynamics of

organic reactions in the gas phase with an accuracy sometimes even exceeding that of experimental methods In

contrast calculations of reaction pathways in solution are still rather laborious and are predominantly used for

investigating mechanisms of known reactions rather than for designing new synthetic transformations For the

latter purpose linear free energy relationships are still indispensable tools Thus pKa values1 are often used for

estimating relative nucleophilic reactivities and leaving group abilities (nucleofugalities) of certain species A

limitation of these so-called Broslashnsted correlations is the fact that pKa values refer to interactions with the

proton while most reactions considered involve formation or cleavage of bonds to carbon We have therefore

developed a Lewis basicity scale2 with respect to C-centered Lewis acids (carbocations and electron-poor p-

systems) and discuss their correlations with nucleophilicities3 and nucleofugalities Analogous relationships

between Lewis acidities electrophilicities and electrofugalities will also be reported4

1) For a comprehensive collection of pKa values see httpibondnankaieducn

2) Mayr H Ammer J Baidya M Maji B Nigst T A Ofial A R Singer T Am Chem Soc

2015 137 2580minus2599

3) For a collection of nucleophilicity and electrophilicity parameters see

httpwwwcuplmudeocmayrDBintrohtml

4) Mayr H Ofial A R Chem Res 2016 49 952ndash965

12

Pyroelectricity from Non-Polar Crystals Enables Understanding Features of

Crystal Growth and Design

Meir Lahav Elena Meirzadeh Eran Mishuk David Ehre Igor Lubomirsky

Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Pyroelectricity a property of certain crystalline materials is the creation of a temporary surface charge upon

temperature change resulting in an external electric current Thermal movement of the molecules alters their

average positions leading to changes in their dipole moments As a consequence of this property spontaneous

polarization was constricted to the polar directions of the ten polar crystal classes when exposed to temperature

change resulting in the creation of two oppositely charged faces which engender pyroelectricity With the

emergence of modern analytical instruments for measuring electric currents it became possible however to

probe the structures of polar defects and imperfections and near surface polar layers that outline non-polar

crystals In spite of their slight amounts those architectures play indispensible role for the understanding of the

different features that control the macroscopic properties of crystals and provide perceptiveness on the

mechanisms of crystal growth

The following sub-topics will be presented

a) Deciphering the riddle of polarity found in the growth of the centrosymmetric crystals of glycine1-2

b) Enantiomeric disorder within the crystals of DL alanine not detectable by diffraction3

c) Solvent molecules as ldquotailor-maderdquo auxiliary in the control of crystal polymorphism as illustrated with the

three polymorphs of glycine4

d) Pyroelectricity combined with theoretical simulations as a new analytical method for the structure

determination of polar tiny-doped domains in crystals at the molecular level5

(1) Meirzadeh E Sapir L et al JACS 2016 138 14756

(2) Piperno S et al Angew Chem Int Ed 2013 52 6513

(3) Mishuk E et al Cryst Growth Des 2014 14 3839

(4) Meirzadeh E Dishon S work in progress

(5) Meirzadeh E Azuri I et al Nature Com 2016 7 13354

13

Enantioselective Synthesis of Intrinsically Chiral Nanocrystals

Gil Markovich Assaf Ben Moshe Uri Hananel

School of Chemistry Tel Aviv University Tel Aviv Israel

We have recently shown that it is possible to perform an enantioselective synthesis of inorganic nanostructures

made of intrinsically chiral crystals such as a-HgS Te and Se These crystals belonging to the P3121 (or

P3221) chiral space group were grown as nanocrystals in the presence of thiolated chiral molecules such as

cysteine penicillamine or glutathione This led to a preference in the growth of the nanocrystals towards a

certain handedness and consequent strong optical activity

Furthermore in the case of Te nanostructures particular synthesis conditions led to overall chiral shape of the

elongated nanostructures expressed as a twist on the scale of the size of the nanostructures of the order of 100

nm Finally the Te could be easily converted to other materials such as gold or silver telluride while

preserving the chiral shape opening the way to the formation of strongly optically active nanostructures made

of various plasmonic or semiconductor materials

We now demonstrate enantioselective synthesis of another class of materials Lanthanide phosphate hydrate

nanocrystals (also of chiral space group) in the presence of tartaric acid The formed nanocrystals exhibit

substantial degree of circularly polarized luminescence and their enantiomeric excess depends non-linearly on

the enantiomeric excess of the tartaric acid ligands We believe that this system may be useful for studying the

mechanism of enantioselection of the formed nanocrystal seeds in the presence of the chiral molecules

14

Optical Microcavity Devices Containing Organic Materials

Yaakov R Tischler Department of Chemistry Bar-Ilan University Ramat-Gan Israel

When two dielectric mirrors are positioned closely together a half wavelength apart or an integer multiple

thereof they form a Fabry-Peacuterot resonator that can trap light of a specific wavelength for many optical cycles

This resonant light trapping phenomenon is at the heart of vertical cavity surface emitting lasers (VCSELs)

optical switches resonant cavity LEDs and numerous other photonic and optoelectronic devices When organic

materials are situated inside such photonic structures and stability issues are properly addressed amazing

results can be achieved such as strong light-matter coupling at room temperature in both the visible and

infrared (IR) spectral ranges low threshold lasing and super-radiant coupling between molecules Using

microcavities properly designed for use with organics here we show strong light-matter coupling in the mid-IR

spectral range and the first demonstration of a monolayer VCSEL where the gain layer consists of a thin film

of fluorescent dye that is one molecule thick We motivate possible sensor applications for these devices and

discuss the unique physical photochemical and photoelectrochemical processes that can be investigated in

such structures

15

Keynote Lecture

Stability Study of Cation Moieties in Alkaline Anion Exchange Membranes for

Fuel Cell Applications

Dario Dekel1 Charles E Diesendruck2 1Chemical Engineering Technion - Israel Institute of Technology Haifa Israel

2Chemistry Technion - Israel Institute of Technology Haifa Israel

There is an increasing worldwide interest in anion exchange membrane fuel cells (AEMFCs) due to the

potential of this technology to use low cost electrocatalysts promising a considerable cost reduction for new

generation of fuel cell devices However the stability of anion conducting polymers for durable anion exchange

membranes (AEMs) and anion exchange ionomers (AEIs) is still a great concern

Here we present a novel methodology to measure the true alkaline stability of anion conducting polymers to be

used in AEMFCs The new ex-situ technique simulates the environment of an AEMFC during operation where

nucleophilic and basic OH- species in the absence or with scarce amount of water attack the functional groups

of the ionic polymer Using this technique we clearly show the critical effect of water molecules on the alkaline

stability of quaternary ammonium (QA) cations commonly used as functional groups in AEMFCs

The results show that as the water content is reduced the QA cations are more rapidly degraded in the presence

of OH- at room temperature With increasing number of water molecules solvating the hydroxide its

nucleophilicity and basicity are hindered and the QA degradation is significantly slowed These results indicate

that the currently used aqueous alkali ex-situ tests to measure AEM stability may lead to false positive stability

results where anion conducting polymers may appear more alkali stable than they really are

We strongly recommend the adoption of this novel developed technique to measure the true stability of anion

conducting polymers to be used for AEMFCs We believe that this new ex-situ protocol will rapidly lead to

development and selection of best stable polymers for durable and robust AEMFCs

16

Probing the Electrode-Electrolyte Interface in Rechargeable Batteries by Solid

State NMR

Michal Leskes Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Reactions at the electrode-electrolyte interface in lithium ion batteries play a key role in the batteryrsquos

performance and are one of the main causes for cell failure These reactions which lead to the formation of the

solid electrolyte interphase (SEI) ultimately control the reversibility of the cellrsquos Li chemistry and its kinetics

Thus an important part in the development of new high energy storage materials is control over their interfacial

chemistry and reactivity with the electrolyte Nuclear magnetic resonance (NMR) spectroscopy is an excellent

approach for following the formation of interfacial layers as it can detect disordered and heterogeneous phases

providing information on their chemical composition structure and dynamic properties Its main disadvantage

is its low sensitivity which is often a limiting factor when probing the SEI Here Irsquoll describe approaches to

overcome this sensitivity limitation by isotope enrichment as well as the potential of new hyperpolarization

techniques which can provide detailed molecular level insight into the chemistry of the SEI

17

First-Principles Based Studies of Complex Oxide Materials

Ilya Grinberg Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Since their first discovery over 70 years ago complex ferroelectric oxides have been shown to exhibit a wide

variety of physical and chemical properties that enable their use in a broad range of applications In particular

the dynamics in a class of complex ferroelectric solid solutions known as relaxors have been under

investigation due to their glass-like behavior and excellent technological properties Nevertheless despite over

50 years of research the key bonding motifs of relaxor ferroelectrics that give rise to their fascinating properties

such as ultrahigh piezoelectric coefficients high permittivity over a broad temperature range diffuse phase

transition without macroscopic lattice symmetry strong frequency dependence in dielectric response and

phonon anomalies are still subject to debate We use molecular dynamics simulations for the prototypical

Pb(Mg13Nb23)O3-PbTiO3 relaxor material to examine the structure bonding and the spatial and temporal

correlations of relaxors Our simulations show that the unusual properties of relaxors simply stem from the

presence of a multidomain state with an extremely small asymp2-10 nm domain size and that dynamics of relaxors

exhibit striking similarities to those of water arising from the local-environment dependent dipole decoupling

due to chemical bonding variation at particular atomic sites

Ferroelectric materials have also recently attracted increased attention as a candidate class of materials for use

in photovoltaic devices In a series of computational studies of a variety of ferroelectric perovskite oxides we

showed that the physical behaviors of these materials are governed by the simple local structure and chemical

bonding characteristics these can then be modified to rationally design new materials with light absorption

through the visible range that enables the use of these materials in photovoltaic applications

18

Colorimetric Detection of the Early Stages of Aluminum Oxidation Using

Plasmonic Gold NanondashIsland Films

Alexander Tesler1 Eyal Sabatani3 Takumi Sannomiya4 Yishai Feldman2

Alexander Vaskevich1 Israel Rubinstein1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemistry Division Nuclear Research Centre Negev Beer-Sheva Israel

4Materials Science amp Engineering Tokyo Institute of Technology Yokohama Kanagawa

Japan

Corrosion is a natural process of degradation of metallic parts reacting with their environment and is the major

cause of failure of metal structures inndashservice Hence detection of the early stages of environmental oxidation

of metal parts is of great importance Here we present a colorimetric method for monitoring the surface

conditions of aluminum using the localized surface plasmon resonance (LSPR) response of gold nanoparticles

(NPs) prendashdeposited onto the aluminum surface Upon oxidation metallic aluminum transforms to transparent

dielectric aluminum oxide (or hydroxide) In water the formed oxidation product adopts a twondashlayer structure

the bottom layer is thinner and compact while the top layer is thicker and highly porous The gold nanondashisland

layer initially deposited (by evaporationannealing) on the aluminum surface maintains its integrity after

corrosion in water and is located between the two aluminum oxide layers Water oxidation of aluminum

substrates with an overlayer of plasmonic gold nano-islands leads to a pronounced color change which can be

monitored in situ using reflection spectroscopy or colorimetrically by the naked eye Theoretical calculations

show that the major spectral change during corrosion is attributed to the interplay between plasmonic scattering

of the Au NP layer reacting to the changing environment and interference within the bottom aluminum oxide

layer acting as an etalon sandwiched between the Au islands and the underlying aluminum The top porous

oxide layer has only a marginal contribution The results indicate that plasmonic gold NPs are well suited for

realndashtime monitoring of the corrosion kinetics of aluminum and its alloys in aqueous environment and in air

The technique is costndasheffective and can be carried out in the transmission or reflection configuration

19

Vertically Aligned Molybdenum Disulfide for Efficient Lithium Storage

Victor Shokhen1 Yana Miroshnikov1 Gregory Gershinsky1 Noam Gotlib2 Chen Stern2

Doron Naveh2 David Zitoun1 1Chemistry Nanotechnology and Advanced Materials (BINA) Bar-Ilan University

Ramat-Gan Israel 2Faculty of Engineering Bar-Ilan University Ramat-Gan Israel

Layered transition-metal disulfides (LTMDs) have played a prominent role in the development of electronic

energy conversion and storage devices Molybdenum disulfide (MoS2) has been widely investigated as a highly

efficient alternative to existing materials Most fabrication pathways of MoS2 focus on its planar growth on

various substrates to reach high-quality layers with planar orientation (PO) Nevertheless in most energy-

storage applications the most relevant orientation is the vertical alignment (VA) of well-defined layers VA

growth paves the way to highly dense devices with exposed active sites on the surface Here the chemical

vapor deposition (CVD) process has been investigated to grow 2H-MoS2 films hundreds of nanometers thick

with VA stacking The films show large domains of perfectly aligned layers with high crystallinity and density

and low surface roughness CVD-grown VA-MoS2 films show superior behavior in lithium storage with stable

capacity even at a high current density compared to PO-MoS2 films The VA-MoS2 films show a high

reversible capacity of 800 mAhg for lithium storage which corresponds to the full conversion to Mo and Li2S

HR-TEM images of VA-MoS2 Capacity of VA-MoS2 compare to PO-MoS2

20

Tailoring the Electronic Structure of TeY-doped NbBiO4 using Oxygen-

vacancy for All-oxide PV Application A Theoretical and Experimental Study

Vijay Singh Susanta Das David Keller Dan Thomas Major

Department of Chemistry Bar-Ilan University Ramat-Gan Israel

First principles studies of point defects and impurities in semiconductors insulators and metals have become an

integral part of material research over the last few decades1 Point defects and impurities often have decisive

effects on material properties2 3 Recently using density functional theory (DFT) calculations we have revealed

that Bi2O3 is a low band-gap material and the obtained energy band-gap 230 eV lies in the region of PV

interest The observed optical transitions between the valence band (VB) (O-2p states) and the conduction band

(CB) (Bi-6p states) are not allowed due to violation of the dipole selection rule (Δl =+-1) Therefore Bi2O3 is

not a potential absorber material for photovoltaic (PV) applications With the aid of DFT calculations and

experimental measurements we have also studied the NbBiO4 system extensively and our results revealed that

its valence band (VB) and conduction band (CB) consist of optically active states but its large energy band gap

350 eV puts a constraint on its use as an absorber material In the present talk I shall discuss how with the

help of suitable doping as well as oxygen vacancy we managed to reduce the energy band gap of NbBiO4 from

350 eV to 220 eV without changing its electronic structure The observed band-gap is in the region of PV

interest and transitions between the CB and VB states are optically allowed Using COHP (energy resolved

visualization of chemical bonding) calculations we revealed that Y doping in NbBiO4 significantly reduces the

covalent bonding between Bi and nearest neighbors oxygen ions from 100 eVbond to 010 eVbond As a

consequence the computed oxygen defect formation energies for Y-doped NbBiO4 system is lower than the

oxygen defect formation energies of the pure NbBiO4 system contributing to a large oxygen-defect

concentration Thus the significance of oxygen vacancy in Y-doped NbBiO4 (YBi site only) was revealed

and this study might serve to design better PV absorber materials in the future

References

1] Freysoldt C Grabowski B Hickel T Neugebauer J Kresse G Janotti A Van de Walle C G First-

principles calculations for point defects in solids Rev Mod Phys 2014 86 253-305

2] Ganguli N Dasgupta I Sanyal B Electronic structure and magnetism of transition metal doped Zn12O12

clusters Role of defects J Appl Phys 2010 108 123911

3] Yavo N Smith A D Yeheskel O Cohen S Korobko R Wachtel E Slater P R Lubomirsky I

Large Nonclassical Electrostriction in (Y Nb)‐ Stabilized δ‐ Bi2O3 Adv Funct Mater 2016

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

6

Olrsquo Bimane is Learning New Tricks

Flavio Grynszpan1 Partha J Das1 Ankana Roy1 Yael Diskin-Posner2 Iddo Pinkas2

Michael Firer3 Michael Montag1 1Chemical Sciences Ariel University Ariel Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemical Engineering and Biotechnology Ariel University Ariel Israel

Bimanes are hetero-bicyclic molecules that can be readily synthesized in moderate to good yields These low

molecular weight fluorophores were developed by Prof E Kosower and co-workers about 40 years ago[i]

From the two possible diastereomeric forms only syn-bimanes are strongly fluorescent Some bimane

derivatives have become useful as fluorescent probes for different applications ranging from biological labeling

to LASER dyes Recently we showed that when attached to an appropriate carrier moiety syn-bimane can

cross the blood-brain-barrier (BBB) of living mice and be clearly detected in brain tissue[ii] syn-Bimanes

present an N-imide structure as an integral part of their skeleton which in the past was never exploited as a

metal binding motif We showed that a cationic Pd(II) complex (2) containing syn-(MeMe)bimane (1 R1-4 =

Me) as a ligand could be prepared and was fully characterized[iii] We are currently involved in the preparation

of bimane derivatives where the oxygen atoms are replaced by sulfur atoms The novel mono- and di-thioxo-

bimanes are expected to display novel spectroscopic properties and give rise to more stable complexes with

different metals Our latest results with oxo- and thioxo-bimanes their structures chemistry and spectroscopic

studies will be presented

[i] E M Kosower B Pazhenchevsky E Hershkowitz J Am Chem Soc 1978 100 6516

[ii] I Lapidot D Baranes A Pinhasov G Gellerman A Albeck F Grynszpan S E Shatzmiller Med

Chem 2016 12 48

[iii] PJ Das Y Diskin-Posner M Firer M Montag F Grynszpan Dalton Trans 201645 17123-17131

7

Synthesis of Highly Functionalized Alkenylfluorides by Silver-Mediated

Fluorodestannation

Heiko Sommer12 Alois Fuumlrstner1 1Organometallic Chemistry Max-Planck-Institut fuumlr Kohlenforschung Muumllheim an der Ruhr

Germany 2Schulich Faculty of Chemistry Technion - Israel Institute of Technology Haifa Israel

The role of fluorine in synthetic and medicinal chemistry receives an ever-increasing attention as fluorine plays

a unique role in influencing the conformation solubility potency permeability or degradability of small

molecules The late-stage introduction of fluorine is of great interest as it allows the modification of complex

molecules without significantly changing the synthetic route

In conjunction with our previously reported ruthenium-catalyzed directed trans-hydrostannation of internal

alkynes[1] an efficient method for the synthesis of highly elaborate alkenyl fluorides could be implemented

(Scheme 1)[2]

Scheme 1 Hydrostannationfluorodestannation for the synthesis of fluoroolefins

During our studies we developed a mild protocol that allowed us to transform a plethora of alkenylstannanes

into the corresponding fluorides while overcoming competing protodestannation[3] Key to success is the

utilization of the non-hygroscopic salt silver(I) diphenyl phosphinate (AgDPP) as a mediator

We applied this new protocol to the synthesis of highly functionalized biologically relevant compounds

consisting among others of a polyketide derivative a peptide bioisoster and a prostaglandin derivative (Scheme

2)

Scheme 2 Selected examples of the silver-mediated fluorodestannation

Literature

[1] a) S M Rummelt A Fuumlrstner Angew Chem Int Ed 2014 53 3626-3630 b) S M Rummelt K

Radkowski D-A Roşca A Fuumlrstner J Am Chem Soc 2015 137 5506-5519

[2] H Sommer A Fuumlrstner submitted manuscript 2016

[3] M A Tius J K Kawakami Tetrahedron 1995 51 3997-4010

8

Stimuli-responsive Self-immolative Chemiluminescent Polymers

Samer Gnaim Doron Shabat

Organic Chemistry Tel Aviv University Tel Aviv Israel

Molecular probes based on 3-hydroxyphenyl-12-dioxetane chemiluminescence light emission are widely used

for various sensing and diagnostic applications (eg DNA enzymatic and chemical probes) Amplification of

molecular signals is an important task for the development of sensitive diagnostic probes in the field of

chemical sensing Recently various approaches have been introduced to increase the signal-to-noise ratio of

chemiluminescent light emission as a molecular signal

This work describes the design and synthesis of a new class of self-immolative chemiluminescent polymers

constructed of four complementary components ) chemically stable 12-dioxatene analog incorporated an

adamantyl group (bulky substituent) ii) protected 4-hydroxybenzyl alcohol substituent (self-immolative

monomeric linker) iii) a chemical or biological responsive group (eg silyl protecting group) and iv) the

monomers are linked together via carbonate linkage

Our results show that a single cleavage event of the protecting group on the phenol results in the formation of a

quinone derivative of 12-dioxetane which undergoes a rapid 16-elimination to release the leaving group on

the benzyl alcohol A nucleophilic attack on the benzylic-methide position initiates a chemically initiated

electron-exchange luminescence (CIEEL) process affording methyl benzoate and light emission

Using this new class of chemiluminescent polymers introduce the ability to design a novel stimuli responsive

chemilumnescent polymers as an amplification systems

9

Synthesis and Evaluation of NPP1 Inhibitors as Potential Drugs for the

Treatment of OsteoarthritisCPPD Disease

Molhm Nassir1 Shani Journo2 Abed Saady1 Uri Arad2 Bilha Fischer1 1Department of Chemistry Bar-Ilan University Ramat-Gan Israel

2Department of Rheumatology Tel Aviv Medical Center and the Faculty of Medicine Tel Aviv

Israel

Overproduction of extracellular pyrophosphate due to hydrolysis of ATP by NPP1 leads to deposition of

pathological Ca2P2O7H2O (CPPD) in cartilage resulting in a degenerative joint disease (CPPD disease) which

has no cure We explored the hypothesis that NPP1 inhibitors may be therapeutic agents for CPPD disease by

inhibiting the hydrolysis of ATP Specifically we synthesized novel analogs of ADP (an NPP1 substrate) in

which the Pab bridging oxygen atom is replaced by a methylene group and a derivative where both Pab

phosphate groups are replaced by sulfonate groups 1 and the Pb phosphate is replaced by a sulfonate isoster 2

In addition we synthesized an ADP analog in which the ribose ring was cleaved and the primary alcohol was

substituted by bis-phosphonate 3 To predict the ability of the derivatives to inhibit NPP1 we evaluated the

affinity and selectivity of the analogs to Zn2+ involved in NPP1rsquos catalytic activity We titrated the analogs with

Zn2+- or Ca2+ ions and monitored the titrations by UV Analogs 1 and 2 selectively coordinated Zn2+ and not

Ca2+ and formed ZnL2 complexes whereas analog 3 showed no affinity for Zn2+ and Ca2+ ions Next analogs

1 2 and 3 have been evaluated for their inhibitory effect on NPP1 in human chondrocytes Analog 3 proved to

be a promising inhibitor reducing NPPase activity in human chondrocytes by 90 at 100 microM vs analogs 1

and 2 (40 and 30 inhibition at 100 microM) Analogs 1 2 and 3 were found to be NPP selective showing no

activity at TNAP In summary analog 3 was found to be an effective and selective NPP1 inhibitor in human

chondrocytes Since analog 3 is a poor Zn2+-chelator we hypothesize that its inhibitory effect may be related to

its high flexibility at NPP1rsquos catalytic site

10

Evaluating the Peptide Structure Prediction Capabilities of a Purely Ab-Initio

Method

Moshe Goldstein13 Moshe Amitay2 1Department of Computer Science Jerusalem College of Technology Jerusalem Israel

2Department of Bioinformatics Jerusalem College of Technology Jerusalem Israel 3The Fritz Haber Research Center The Hebrew University of Jerusalem Jerusalem Israel

Peptides such as hormones and antibiotics play many biological functions Peptides` tertiary structures are of

paramount importance for understanding their function as well as the interactions with other molecules

DEEPSAM[1] (Diffusion Equation Evolutionary Programming Simulated Annealing Method) is a novel purely

ab-initio global optimization algorithm aimed to predict the structure of peptides and proteins from amino acid

sequence without any preliminary assumption This method is an Evolutionary Programming algorithm whose

mutation operators are built by hybridizing the advantages of three well-known optimization methods -

Diffusion Equation Method (DEM) Molecular Dynamics Simulated Annealing (MDSA) and the BFGS quasi-

Newton local minimization method

In principle DEEPSAM requires much less computing resources and is much faster than other structure

prediction methods such as Replica Exchange Molecular Dynamics (REMD) and therefore seems to be more

suitable for industrial use

The goal of this study has been to further evaluate the structure prediction accuracy of the DEEPSAM

algorithm by running it against a large number of known NMR structures of linear peptides (10-20 residues) in

an aqueous environment modeled by the GBSA implicit solvent model

[1] M Goldstein E Fredj and R B Gerber A New Hybrid Algorithm for Finding the Lowest Minima of

Potential Surfaces Approach and Applications to Peptides J of Computational Chemistry vol 32 pp 1785ndash

1800 (2011)

11

Keynote Lecture

Quantification of Polar Organic Reactivity

Herbert Mayr Department of Chemistry Ludwig-Maximilian-University Munich Muenchen Germany

The precision of quantum chemical calculations has reached a level that they can predict the thermodynamics of

organic reactions in the gas phase with an accuracy sometimes even exceeding that of experimental methods In

contrast calculations of reaction pathways in solution are still rather laborious and are predominantly used for

investigating mechanisms of known reactions rather than for designing new synthetic transformations For the

latter purpose linear free energy relationships are still indispensable tools Thus pKa values1 are often used for

estimating relative nucleophilic reactivities and leaving group abilities (nucleofugalities) of certain species A

limitation of these so-called Broslashnsted correlations is the fact that pKa values refer to interactions with the

proton while most reactions considered involve formation or cleavage of bonds to carbon We have therefore

developed a Lewis basicity scale2 with respect to C-centered Lewis acids (carbocations and electron-poor p-

systems) and discuss their correlations with nucleophilicities3 and nucleofugalities Analogous relationships

between Lewis acidities electrophilicities and electrofugalities will also be reported4

1) For a comprehensive collection of pKa values see httpibondnankaieducn

2) Mayr H Ammer J Baidya M Maji B Nigst T A Ofial A R Singer T Am Chem Soc

2015 137 2580minus2599

3) For a collection of nucleophilicity and electrophilicity parameters see

httpwwwcuplmudeocmayrDBintrohtml

4) Mayr H Ofial A R Chem Res 2016 49 952ndash965

12

Pyroelectricity from Non-Polar Crystals Enables Understanding Features of

Crystal Growth and Design

Meir Lahav Elena Meirzadeh Eran Mishuk David Ehre Igor Lubomirsky

Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Pyroelectricity a property of certain crystalline materials is the creation of a temporary surface charge upon

temperature change resulting in an external electric current Thermal movement of the molecules alters their

average positions leading to changes in their dipole moments As a consequence of this property spontaneous

polarization was constricted to the polar directions of the ten polar crystal classes when exposed to temperature

change resulting in the creation of two oppositely charged faces which engender pyroelectricity With the

emergence of modern analytical instruments for measuring electric currents it became possible however to

probe the structures of polar defects and imperfections and near surface polar layers that outline non-polar

crystals In spite of their slight amounts those architectures play indispensible role for the understanding of the

different features that control the macroscopic properties of crystals and provide perceptiveness on the

mechanisms of crystal growth

The following sub-topics will be presented

a) Deciphering the riddle of polarity found in the growth of the centrosymmetric crystals of glycine1-2

b) Enantiomeric disorder within the crystals of DL alanine not detectable by diffraction3

c) Solvent molecules as ldquotailor-maderdquo auxiliary in the control of crystal polymorphism as illustrated with the

three polymorphs of glycine4

d) Pyroelectricity combined with theoretical simulations as a new analytical method for the structure

determination of polar tiny-doped domains in crystals at the molecular level5

(1) Meirzadeh E Sapir L et al JACS 2016 138 14756

(2) Piperno S et al Angew Chem Int Ed 2013 52 6513

(3) Mishuk E et al Cryst Growth Des 2014 14 3839

(4) Meirzadeh E Dishon S work in progress

(5) Meirzadeh E Azuri I et al Nature Com 2016 7 13354

13

Enantioselective Synthesis of Intrinsically Chiral Nanocrystals

Gil Markovich Assaf Ben Moshe Uri Hananel

School of Chemistry Tel Aviv University Tel Aviv Israel

We have recently shown that it is possible to perform an enantioselective synthesis of inorganic nanostructures

made of intrinsically chiral crystals such as a-HgS Te and Se These crystals belonging to the P3121 (or

P3221) chiral space group were grown as nanocrystals in the presence of thiolated chiral molecules such as

cysteine penicillamine or glutathione This led to a preference in the growth of the nanocrystals towards a

certain handedness and consequent strong optical activity

Furthermore in the case of Te nanostructures particular synthesis conditions led to overall chiral shape of the

elongated nanostructures expressed as a twist on the scale of the size of the nanostructures of the order of 100

nm Finally the Te could be easily converted to other materials such as gold or silver telluride while

preserving the chiral shape opening the way to the formation of strongly optically active nanostructures made

of various plasmonic or semiconductor materials

We now demonstrate enantioselective synthesis of another class of materials Lanthanide phosphate hydrate

nanocrystals (also of chiral space group) in the presence of tartaric acid The formed nanocrystals exhibit

substantial degree of circularly polarized luminescence and their enantiomeric excess depends non-linearly on

the enantiomeric excess of the tartaric acid ligands We believe that this system may be useful for studying the

mechanism of enantioselection of the formed nanocrystal seeds in the presence of the chiral molecules

14

Optical Microcavity Devices Containing Organic Materials

Yaakov R Tischler Department of Chemistry Bar-Ilan University Ramat-Gan Israel

When two dielectric mirrors are positioned closely together a half wavelength apart or an integer multiple

thereof they form a Fabry-Peacuterot resonator that can trap light of a specific wavelength for many optical cycles

This resonant light trapping phenomenon is at the heart of vertical cavity surface emitting lasers (VCSELs)

optical switches resonant cavity LEDs and numerous other photonic and optoelectronic devices When organic

materials are situated inside such photonic structures and stability issues are properly addressed amazing

results can be achieved such as strong light-matter coupling at room temperature in both the visible and

infrared (IR) spectral ranges low threshold lasing and super-radiant coupling between molecules Using

microcavities properly designed for use with organics here we show strong light-matter coupling in the mid-IR

spectral range and the first demonstration of a monolayer VCSEL where the gain layer consists of a thin film

of fluorescent dye that is one molecule thick We motivate possible sensor applications for these devices and

discuss the unique physical photochemical and photoelectrochemical processes that can be investigated in

such structures

15

Keynote Lecture

Stability Study of Cation Moieties in Alkaline Anion Exchange Membranes for

Fuel Cell Applications

Dario Dekel1 Charles E Diesendruck2 1Chemical Engineering Technion - Israel Institute of Technology Haifa Israel

2Chemistry Technion - Israel Institute of Technology Haifa Israel

There is an increasing worldwide interest in anion exchange membrane fuel cells (AEMFCs) due to the

potential of this technology to use low cost electrocatalysts promising a considerable cost reduction for new

generation of fuel cell devices However the stability of anion conducting polymers for durable anion exchange

membranes (AEMs) and anion exchange ionomers (AEIs) is still a great concern

Here we present a novel methodology to measure the true alkaline stability of anion conducting polymers to be

used in AEMFCs The new ex-situ technique simulates the environment of an AEMFC during operation where

nucleophilic and basic OH- species in the absence or with scarce amount of water attack the functional groups

of the ionic polymer Using this technique we clearly show the critical effect of water molecules on the alkaline

stability of quaternary ammonium (QA) cations commonly used as functional groups in AEMFCs

The results show that as the water content is reduced the QA cations are more rapidly degraded in the presence

of OH- at room temperature With increasing number of water molecules solvating the hydroxide its

nucleophilicity and basicity are hindered and the QA degradation is significantly slowed These results indicate

that the currently used aqueous alkali ex-situ tests to measure AEM stability may lead to false positive stability

results where anion conducting polymers may appear more alkali stable than they really are

We strongly recommend the adoption of this novel developed technique to measure the true stability of anion

conducting polymers to be used for AEMFCs We believe that this new ex-situ protocol will rapidly lead to

development and selection of best stable polymers for durable and robust AEMFCs

16

Probing the Electrode-Electrolyte Interface in Rechargeable Batteries by Solid

State NMR

Michal Leskes Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Reactions at the electrode-electrolyte interface in lithium ion batteries play a key role in the batteryrsquos

performance and are one of the main causes for cell failure These reactions which lead to the formation of the

solid electrolyte interphase (SEI) ultimately control the reversibility of the cellrsquos Li chemistry and its kinetics

Thus an important part in the development of new high energy storage materials is control over their interfacial

chemistry and reactivity with the electrolyte Nuclear magnetic resonance (NMR) spectroscopy is an excellent

approach for following the formation of interfacial layers as it can detect disordered and heterogeneous phases

providing information on their chemical composition structure and dynamic properties Its main disadvantage

is its low sensitivity which is often a limiting factor when probing the SEI Here Irsquoll describe approaches to

overcome this sensitivity limitation by isotope enrichment as well as the potential of new hyperpolarization

techniques which can provide detailed molecular level insight into the chemistry of the SEI

17

First-Principles Based Studies of Complex Oxide Materials

Ilya Grinberg Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Since their first discovery over 70 years ago complex ferroelectric oxides have been shown to exhibit a wide

variety of physical and chemical properties that enable their use in a broad range of applications In particular

the dynamics in a class of complex ferroelectric solid solutions known as relaxors have been under

investigation due to their glass-like behavior and excellent technological properties Nevertheless despite over

50 years of research the key bonding motifs of relaxor ferroelectrics that give rise to their fascinating properties

such as ultrahigh piezoelectric coefficients high permittivity over a broad temperature range diffuse phase

transition without macroscopic lattice symmetry strong frequency dependence in dielectric response and

phonon anomalies are still subject to debate We use molecular dynamics simulations for the prototypical

Pb(Mg13Nb23)O3-PbTiO3 relaxor material to examine the structure bonding and the spatial and temporal

correlations of relaxors Our simulations show that the unusual properties of relaxors simply stem from the

presence of a multidomain state with an extremely small asymp2-10 nm domain size and that dynamics of relaxors

exhibit striking similarities to those of water arising from the local-environment dependent dipole decoupling

due to chemical bonding variation at particular atomic sites

Ferroelectric materials have also recently attracted increased attention as a candidate class of materials for use

in photovoltaic devices In a series of computational studies of a variety of ferroelectric perovskite oxides we

showed that the physical behaviors of these materials are governed by the simple local structure and chemical

bonding characteristics these can then be modified to rationally design new materials with light absorption

through the visible range that enables the use of these materials in photovoltaic applications

18

Colorimetric Detection of the Early Stages of Aluminum Oxidation Using

Plasmonic Gold NanondashIsland Films

Alexander Tesler1 Eyal Sabatani3 Takumi Sannomiya4 Yishai Feldman2

Alexander Vaskevich1 Israel Rubinstein1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemistry Division Nuclear Research Centre Negev Beer-Sheva Israel

4Materials Science amp Engineering Tokyo Institute of Technology Yokohama Kanagawa

Japan

Corrosion is a natural process of degradation of metallic parts reacting with their environment and is the major

cause of failure of metal structures inndashservice Hence detection of the early stages of environmental oxidation

of metal parts is of great importance Here we present a colorimetric method for monitoring the surface

conditions of aluminum using the localized surface plasmon resonance (LSPR) response of gold nanoparticles

(NPs) prendashdeposited onto the aluminum surface Upon oxidation metallic aluminum transforms to transparent

dielectric aluminum oxide (or hydroxide) In water the formed oxidation product adopts a twondashlayer structure

the bottom layer is thinner and compact while the top layer is thicker and highly porous The gold nanondashisland

layer initially deposited (by evaporationannealing) on the aluminum surface maintains its integrity after

corrosion in water and is located between the two aluminum oxide layers Water oxidation of aluminum

substrates with an overlayer of plasmonic gold nano-islands leads to a pronounced color change which can be

monitored in situ using reflection spectroscopy or colorimetrically by the naked eye Theoretical calculations

show that the major spectral change during corrosion is attributed to the interplay between plasmonic scattering

of the Au NP layer reacting to the changing environment and interference within the bottom aluminum oxide

layer acting as an etalon sandwiched between the Au islands and the underlying aluminum The top porous

oxide layer has only a marginal contribution The results indicate that plasmonic gold NPs are well suited for

realndashtime monitoring of the corrosion kinetics of aluminum and its alloys in aqueous environment and in air

The technique is costndasheffective and can be carried out in the transmission or reflection configuration

19

Vertically Aligned Molybdenum Disulfide for Efficient Lithium Storage

Victor Shokhen1 Yana Miroshnikov1 Gregory Gershinsky1 Noam Gotlib2 Chen Stern2

Doron Naveh2 David Zitoun1 1Chemistry Nanotechnology and Advanced Materials (BINA) Bar-Ilan University

Ramat-Gan Israel 2Faculty of Engineering Bar-Ilan University Ramat-Gan Israel

Layered transition-metal disulfides (LTMDs) have played a prominent role in the development of electronic

energy conversion and storage devices Molybdenum disulfide (MoS2) has been widely investigated as a highly

efficient alternative to existing materials Most fabrication pathways of MoS2 focus on its planar growth on

various substrates to reach high-quality layers with planar orientation (PO) Nevertheless in most energy-

storage applications the most relevant orientation is the vertical alignment (VA) of well-defined layers VA

growth paves the way to highly dense devices with exposed active sites on the surface Here the chemical

vapor deposition (CVD) process has been investigated to grow 2H-MoS2 films hundreds of nanometers thick

with VA stacking The films show large domains of perfectly aligned layers with high crystallinity and density

and low surface roughness CVD-grown VA-MoS2 films show superior behavior in lithium storage with stable

capacity even at a high current density compared to PO-MoS2 films The VA-MoS2 films show a high

reversible capacity of 800 mAhg for lithium storage which corresponds to the full conversion to Mo and Li2S

HR-TEM images of VA-MoS2 Capacity of VA-MoS2 compare to PO-MoS2

20

Tailoring the Electronic Structure of TeY-doped NbBiO4 using Oxygen-

vacancy for All-oxide PV Application A Theoretical and Experimental Study

Vijay Singh Susanta Das David Keller Dan Thomas Major

Department of Chemistry Bar-Ilan University Ramat-Gan Israel

First principles studies of point defects and impurities in semiconductors insulators and metals have become an

integral part of material research over the last few decades1 Point defects and impurities often have decisive

effects on material properties2 3 Recently using density functional theory (DFT) calculations we have revealed

that Bi2O3 is a low band-gap material and the obtained energy band-gap 230 eV lies in the region of PV

interest The observed optical transitions between the valence band (VB) (O-2p states) and the conduction band

(CB) (Bi-6p states) are not allowed due to violation of the dipole selection rule (Δl =+-1) Therefore Bi2O3 is

not a potential absorber material for photovoltaic (PV) applications With the aid of DFT calculations and

experimental measurements we have also studied the NbBiO4 system extensively and our results revealed that

its valence band (VB) and conduction band (CB) consist of optically active states but its large energy band gap

350 eV puts a constraint on its use as an absorber material In the present talk I shall discuss how with the

help of suitable doping as well as oxygen vacancy we managed to reduce the energy band gap of NbBiO4 from

350 eV to 220 eV without changing its electronic structure The observed band-gap is in the region of PV

interest and transitions between the CB and VB states are optically allowed Using COHP (energy resolved

visualization of chemical bonding) calculations we revealed that Y doping in NbBiO4 significantly reduces the

covalent bonding between Bi and nearest neighbors oxygen ions from 100 eVbond to 010 eVbond As a

consequence the computed oxygen defect formation energies for Y-doped NbBiO4 system is lower than the

oxygen defect formation energies of the pure NbBiO4 system contributing to a large oxygen-defect

concentration Thus the significance of oxygen vacancy in Y-doped NbBiO4 (YBi site only) was revealed

and this study might serve to design better PV absorber materials in the future

References

1] Freysoldt C Grabowski B Hickel T Neugebauer J Kresse G Janotti A Van de Walle C G First-

principles calculations for point defects in solids Rev Mod Phys 2014 86 253-305

2] Ganguli N Dasgupta I Sanyal B Electronic structure and magnetism of transition metal doped Zn12O12

clusters Role of defects J Appl Phys 2010 108 123911

3] Yavo N Smith A D Yeheskel O Cohen S Korobko R Wachtel E Slater P R Lubomirsky I

Large Nonclassical Electrostriction in (Y Nb)‐ Stabilized δ‐ Bi2O3 Adv Funct Mater 2016

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

7

Synthesis of Highly Functionalized Alkenylfluorides by Silver-Mediated

Fluorodestannation

Heiko Sommer12 Alois Fuumlrstner1 1Organometallic Chemistry Max-Planck-Institut fuumlr Kohlenforschung Muumllheim an der Ruhr

Germany 2Schulich Faculty of Chemistry Technion - Israel Institute of Technology Haifa Israel

The role of fluorine in synthetic and medicinal chemistry receives an ever-increasing attention as fluorine plays

a unique role in influencing the conformation solubility potency permeability or degradability of small

molecules The late-stage introduction of fluorine is of great interest as it allows the modification of complex

molecules without significantly changing the synthetic route

In conjunction with our previously reported ruthenium-catalyzed directed trans-hydrostannation of internal

alkynes[1] an efficient method for the synthesis of highly elaborate alkenyl fluorides could be implemented

(Scheme 1)[2]

Scheme 1 Hydrostannationfluorodestannation for the synthesis of fluoroolefins

During our studies we developed a mild protocol that allowed us to transform a plethora of alkenylstannanes

into the corresponding fluorides while overcoming competing protodestannation[3] Key to success is the

utilization of the non-hygroscopic salt silver(I) diphenyl phosphinate (AgDPP) as a mediator

We applied this new protocol to the synthesis of highly functionalized biologically relevant compounds

consisting among others of a polyketide derivative a peptide bioisoster and a prostaglandin derivative (Scheme

2)

Scheme 2 Selected examples of the silver-mediated fluorodestannation

Literature

[1] a) S M Rummelt A Fuumlrstner Angew Chem Int Ed 2014 53 3626-3630 b) S M Rummelt K

Radkowski D-A Roşca A Fuumlrstner J Am Chem Soc 2015 137 5506-5519

[2] H Sommer A Fuumlrstner submitted manuscript 2016

[3] M A Tius J K Kawakami Tetrahedron 1995 51 3997-4010

8

Stimuli-responsive Self-immolative Chemiluminescent Polymers

Samer Gnaim Doron Shabat

Organic Chemistry Tel Aviv University Tel Aviv Israel

Molecular probes based on 3-hydroxyphenyl-12-dioxetane chemiluminescence light emission are widely used

for various sensing and diagnostic applications (eg DNA enzymatic and chemical probes) Amplification of

molecular signals is an important task for the development of sensitive diagnostic probes in the field of

chemical sensing Recently various approaches have been introduced to increase the signal-to-noise ratio of

chemiluminescent light emission as a molecular signal

This work describes the design and synthesis of a new class of self-immolative chemiluminescent polymers

constructed of four complementary components ) chemically stable 12-dioxatene analog incorporated an

adamantyl group (bulky substituent) ii) protected 4-hydroxybenzyl alcohol substituent (self-immolative

monomeric linker) iii) a chemical or biological responsive group (eg silyl protecting group) and iv) the

monomers are linked together via carbonate linkage

Our results show that a single cleavage event of the protecting group on the phenol results in the formation of a

quinone derivative of 12-dioxetane which undergoes a rapid 16-elimination to release the leaving group on

the benzyl alcohol A nucleophilic attack on the benzylic-methide position initiates a chemically initiated

electron-exchange luminescence (CIEEL) process affording methyl benzoate and light emission

Using this new class of chemiluminescent polymers introduce the ability to design a novel stimuli responsive

chemilumnescent polymers as an amplification systems

9

Synthesis and Evaluation of NPP1 Inhibitors as Potential Drugs for the

Treatment of OsteoarthritisCPPD Disease

Molhm Nassir1 Shani Journo2 Abed Saady1 Uri Arad2 Bilha Fischer1 1Department of Chemistry Bar-Ilan University Ramat-Gan Israel

2Department of Rheumatology Tel Aviv Medical Center and the Faculty of Medicine Tel Aviv

Israel

Overproduction of extracellular pyrophosphate due to hydrolysis of ATP by NPP1 leads to deposition of

pathological Ca2P2O7H2O (CPPD) in cartilage resulting in a degenerative joint disease (CPPD disease) which

has no cure We explored the hypothesis that NPP1 inhibitors may be therapeutic agents for CPPD disease by

inhibiting the hydrolysis of ATP Specifically we synthesized novel analogs of ADP (an NPP1 substrate) in

which the Pab bridging oxygen atom is replaced by a methylene group and a derivative where both Pab

phosphate groups are replaced by sulfonate groups 1 and the Pb phosphate is replaced by a sulfonate isoster 2

In addition we synthesized an ADP analog in which the ribose ring was cleaved and the primary alcohol was

substituted by bis-phosphonate 3 To predict the ability of the derivatives to inhibit NPP1 we evaluated the

affinity and selectivity of the analogs to Zn2+ involved in NPP1rsquos catalytic activity We titrated the analogs with

Zn2+- or Ca2+ ions and monitored the titrations by UV Analogs 1 and 2 selectively coordinated Zn2+ and not

Ca2+ and formed ZnL2 complexes whereas analog 3 showed no affinity for Zn2+ and Ca2+ ions Next analogs

1 2 and 3 have been evaluated for their inhibitory effect on NPP1 in human chondrocytes Analog 3 proved to

be a promising inhibitor reducing NPPase activity in human chondrocytes by 90 at 100 microM vs analogs 1

and 2 (40 and 30 inhibition at 100 microM) Analogs 1 2 and 3 were found to be NPP selective showing no

activity at TNAP In summary analog 3 was found to be an effective and selective NPP1 inhibitor in human

chondrocytes Since analog 3 is a poor Zn2+-chelator we hypothesize that its inhibitory effect may be related to

its high flexibility at NPP1rsquos catalytic site

10

Evaluating the Peptide Structure Prediction Capabilities of a Purely Ab-Initio

Method

Moshe Goldstein13 Moshe Amitay2 1Department of Computer Science Jerusalem College of Technology Jerusalem Israel

2Department of Bioinformatics Jerusalem College of Technology Jerusalem Israel 3The Fritz Haber Research Center The Hebrew University of Jerusalem Jerusalem Israel

Peptides such as hormones and antibiotics play many biological functions Peptides` tertiary structures are of

paramount importance for understanding their function as well as the interactions with other molecules

DEEPSAM[1] (Diffusion Equation Evolutionary Programming Simulated Annealing Method) is a novel purely

ab-initio global optimization algorithm aimed to predict the structure of peptides and proteins from amino acid

sequence without any preliminary assumption This method is an Evolutionary Programming algorithm whose

mutation operators are built by hybridizing the advantages of three well-known optimization methods -

Diffusion Equation Method (DEM) Molecular Dynamics Simulated Annealing (MDSA) and the BFGS quasi-

Newton local minimization method

In principle DEEPSAM requires much less computing resources and is much faster than other structure

prediction methods such as Replica Exchange Molecular Dynamics (REMD) and therefore seems to be more

suitable for industrial use

The goal of this study has been to further evaluate the structure prediction accuracy of the DEEPSAM

algorithm by running it against a large number of known NMR structures of linear peptides (10-20 residues) in

an aqueous environment modeled by the GBSA implicit solvent model

[1] M Goldstein E Fredj and R B Gerber A New Hybrid Algorithm for Finding the Lowest Minima of

Potential Surfaces Approach and Applications to Peptides J of Computational Chemistry vol 32 pp 1785ndash

1800 (2011)

11

Keynote Lecture

Quantification of Polar Organic Reactivity

Herbert Mayr Department of Chemistry Ludwig-Maximilian-University Munich Muenchen Germany

The precision of quantum chemical calculations has reached a level that they can predict the thermodynamics of

organic reactions in the gas phase with an accuracy sometimes even exceeding that of experimental methods In

contrast calculations of reaction pathways in solution are still rather laborious and are predominantly used for

investigating mechanisms of known reactions rather than for designing new synthetic transformations For the

latter purpose linear free energy relationships are still indispensable tools Thus pKa values1 are often used for

estimating relative nucleophilic reactivities and leaving group abilities (nucleofugalities) of certain species A

limitation of these so-called Broslashnsted correlations is the fact that pKa values refer to interactions with the

proton while most reactions considered involve formation or cleavage of bonds to carbon We have therefore

developed a Lewis basicity scale2 with respect to C-centered Lewis acids (carbocations and electron-poor p-

systems) and discuss their correlations with nucleophilicities3 and nucleofugalities Analogous relationships

between Lewis acidities electrophilicities and electrofugalities will also be reported4

1) For a comprehensive collection of pKa values see httpibondnankaieducn

2) Mayr H Ammer J Baidya M Maji B Nigst T A Ofial A R Singer T Am Chem Soc

2015 137 2580minus2599

3) For a collection of nucleophilicity and electrophilicity parameters see

httpwwwcuplmudeocmayrDBintrohtml

4) Mayr H Ofial A R Chem Res 2016 49 952ndash965

12

Pyroelectricity from Non-Polar Crystals Enables Understanding Features of

Crystal Growth and Design

Meir Lahav Elena Meirzadeh Eran Mishuk David Ehre Igor Lubomirsky

Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Pyroelectricity a property of certain crystalline materials is the creation of a temporary surface charge upon

temperature change resulting in an external electric current Thermal movement of the molecules alters their

average positions leading to changes in their dipole moments As a consequence of this property spontaneous

polarization was constricted to the polar directions of the ten polar crystal classes when exposed to temperature

change resulting in the creation of two oppositely charged faces which engender pyroelectricity With the

emergence of modern analytical instruments for measuring electric currents it became possible however to

probe the structures of polar defects and imperfections and near surface polar layers that outline non-polar

crystals In spite of their slight amounts those architectures play indispensible role for the understanding of the

different features that control the macroscopic properties of crystals and provide perceptiveness on the

mechanisms of crystal growth

The following sub-topics will be presented

a) Deciphering the riddle of polarity found in the growth of the centrosymmetric crystals of glycine1-2

b) Enantiomeric disorder within the crystals of DL alanine not detectable by diffraction3

c) Solvent molecules as ldquotailor-maderdquo auxiliary in the control of crystal polymorphism as illustrated with the

three polymorphs of glycine4

d) Pyroelectricity combined with theoretical simulations as a new analytical method for the structure

determination of polar tiny-doped domains in crystals at the molecular level5

(1) Meirzadeh E Sapir L et al JACS 2016 138 14756

(2) Piperno S et al Angew Chem Int Ed 2013 52 6513

(3) Mishuk E et al Cryst Growth Des 2014 14 3839

(4) Meirzadeh E Dishon S work in progress

(5) Meirzadeh E Azuri I et al Nature Com 2016 7 13354

13

Enantioselective Synthesis of Intrinsically Chiral Nanocrystals

Gil Markovich Assaf Ben Moshe Uri Hananel

School of Chemistry Tel Aviv University Tel Aviv Israel

We have recently shown that it is possible to perform an enantioselective synthesis of inorganic nanostructures

made of intrinsically chiral crystals such as a-HgS Te and Se These crystals belonging to the P3121 (or

P3221) chiral space group were grown as nanocrystals in the presence of thiolated chiral molecules such as

cysteine penicillamine or glutathione This led to a preference in the growth of the nanocrystals towards a

certain handedness and consequent strong optical activity

Furthermore in the case of Te nanostructures particular synthesis conditions led to overall chiral shape of the

elongated nanostructures expressed as a twist on the scale of the size of the nanostructures of the order of 100

nm Finally the Te could be easily converted to other materials such as gold or silver telluride while

preserving the chiral shape opening the way to the formation of strongly optically active nanostructures made

of various plasmonic or semiconductor materials

We now demonstrate enantioselective synthesis of another class of materials Lanthanide phosphate hydrate

nanocrystals (also of chiral space group) in the presence of tartaric acid The formed nanocrystals exhibit

substantial degree of circularly polarized luminescence and their enantiomeric excess depends non-linearly on

the enantiomeric excess of the tartaric acid ligands We believe that this system may be useful for studying the

mechanism of enantioselection of the formed nanocrystal seeds in the presence of the chiral molecules

14

Optical Microcavity Devices Containing Organic Materials

Yaakov R Tischler Department of Chemistry Bar-Ilan University Ramat-Gan Israel

When two dielectric mirrors are positioned closely together a half wavelength apart or an integer multiple

thereof they form a Fabry-Peacuterot resonator that can trap light of a specific wavelength for many optical cycles

This resonant light trapping phenomenon is at the heart of vertical cavity surface emitting lasers (VCSELs)

optical switches resonant cavity LEDs and numerous other photonic and optoelectronic devices When organic

materials are situated inside such photonic structures and stability issues are properly addressed amazing

results can be achieved such as strong light-matter coupling at room temperature in both the visible and

infrared (IR) spectral ranges low threshold lasing and super-radiant coupling between molecules Using

microcavities properly designed for use with organics here we show strong light-matter coupling in the mid-IR

spectral range and the first demonstration of a monolayer VCSEL where the gain layer consists of a thin film

of fluorescent dye that is one molecule thick We motivate possible sensor applications for these devices and

discuss the unique physical photochemical and photoelectrochemical processes that can be investigated in

such structures

15

Keynote Lecture

Stability Study of Cation Moieties in Alkaline Anion Exchange Membranes for

Fuel Cell Applications

Dario Dekel1 Charles E Diesendruck2 1Chemical Engineering Technion - Israel Institute of Technology Haifa Israel

2Chemistry Technion - Israel Institute of Technology Haifa Israel

There is an increasing worldwide interest in anion exchange membrane fuel cells (AEMFCs) due to the

potential of this technology to use low cost electrocatalysts promising a considerable cost reduction for new

generation of fuel cell devices However the stability of anion conducting polymers for durable anion exchange

membranes (AEMs) and anion exchange ionomers (AEIs) is still a great concern

Here we present a novel methodology to measure the true alkaline stability of anion conducting polymers to be

used in AEMFCs The new ex-situ technique simulates the environment of an AEMFC during operation where

nucleophilic and basic OH- species in the absence or with scarce amount of water attack the functional groups

of the ionic polymer Using this technique we clearly show the critical effect of water molecules on the alkaline

stability of quaternary ammonium (QA) cations commonly used as functional groups in AEMFCs

The results show that as the water content is reduced the QA cations are more rapidly degraded in the presence

of OH- at room temperature With increasing number of water molecules solvating the hydroxide its

nucleophilicity and basicity are hindered and the QA degradation is significantly slowed These results indicate

that the currently used aqueous alkali ex-situ tests to measure AEM stability may lead to false positive stability

results where anion conducting polymers may appear more alkali stable than they really are

We strongly recommend the adoption of this novel developed technique to measure the true stability of anion

conducting polymers to be used for AEMFCs We believe that this new ex-situ protocol will rapidly lead to

development and selection of best stable polymers for durable and robust AEMFCs

16

Probing the Electrode-Electrolyte Interface in Rechargeable Batteries by Solid

State NMR

Michal Leskes Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Reactions at the electrode-electrolyte interface in lithium ion batteries play a key role in the batteryrsquos

performance and are one of the main causes for cell failure These reactions which lead to the formation of the

solid electrolyte interphase (SEI) ultimately control the reversibility of the cellrsquos Li chemistry and its kinetics

Thus an important part in the development of new high energy storage materials is control over their interfacial

chemistry and reactivity with the electrolyte Nuclear magnetic resonance (NMR) spectroscopy is an excellent

approach for following the formation of interfacial layers as it can detect disordered and heterogeneous phases

providing information on their chemical composition structure and dynamic properties Its main disadvantage

is its low sensitivity which is often a limiting factor when probing the SEI Here Irsquoll describe approaches to

overcome this sensitivity limitation by isotope enrichment as well as the potential of new hyperpolarization

techniques which can provide detailed molecular level insight into the chemistry of the SEI

17

First-Principles Based Studies of Complex Oxide Materials

Ilya Grinberg Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Since their first discovery over 70 years ago complex ferroelectric oxides have been shown to exhibit a wide

variety of physical and chemical properties that enable their use in a broad range of applications In particular

the dynamics in a class of complex ferroelectric solid solutions known as relaxors have been under

investigation due to their glass-like behavior and excellent technological properties Nevertheless despite over

50 years of research the key bonding motifs of relaxor ferroelectrics that give rise to their fascinating properties

such as ultrahigh piezoelectric coefficients high permittivity over a broad temperature range diffuse phase

transition without macroscopic lattice symmetry strong frequency dependence in dielectric response and

phonon anomalies are still subject to debate We use molecular dynamics simulations for the prototypical

Pb(Mg13Nb23)O3-PbTiO3 relaxor material to examine the structure bonding and the spatial and temporal

correlations of relaxors Our simulations show that the unusual properties of relaxors simply stem from the

presence of a multidomain state with an extremely small asymp2-10 nm domain size and that dynamics of relaxors

exhibit striking similarities to those of water arising from the local-environment dependent dipole decoupling

due to chemical bonding variation at particular atomic sites

Ferroelectric materials have also recently attracted increased attention as a candidate class of materials for use

in photovoltaic devices In a series of computational studies of a variety of ferroelectric perovskite oxides we

showed that the physical behaviors of these materials are governed by the simple local structure and chemical

bonding characteristics these can then be modified to rationally design new materials with light absorption

through the visible range that enables the use of these materials in photovoltaic applications

18

Colorimetric Detection of the Early Stages of Aluminum Oxidation Using

Plasmonic Gold NanondashIsland Films

Alexander Tesler1 Eyal Sabatani3 Takumi Sannomiya4 Yishai Feldman2

Alexander Vaskevich1 Israel Rubinstein1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemistry Division Nuclear Research Centre Negev Beer-Sheva Israel

4Materials Science amp Engineering Tokyo Institute of Technology Yokohama Kanagawa

Japan

Corrosion is a natural process of degradation of metallic parts reacting with their environment and is the major

cause of failure of metal structures inndashservice Hence detection of the early stages of environmental oxidation

of metal parts is of great importance Here we present a colorimetric method for monitoring the surface

conditions of aluminum using the localized surface plasmon resonance (LSPR) response of gold nanoparticles

(NPs) prendashdeposited onto the aluminum surface Upon oxidation metallic aluminum transforms to transparent

dielectric aluminum oxide (or hydroxide) In water the formed oxidation product adopts a twondashlayer structure

the bottom layer is thinner and compact while the top layer is thicker and highly porous The gold nanondashisland

layer initially deposited (by evaporationannealing) on the aluminum surface maintains its integrity after

corrosion in water and is located between the two aluminum oxide layers Water oxidation of aluminum

substrates with an overlayer of plasmonic gold nano-islands leads to a pronounced color change which can be

monitored in situ using reflection spectroscopy or colorimetrically by the naked eye Theoretical calculations

show that the major spectral change during corrosion is attributed to the interplay between plasmonic scattering

of the Au NP layer reacting to the changing environment and interference within the bottom aluminum oxide

layer acting as an etalon sandwiched between the Au islands and the underlying aluminum The top porous

oxide layer has only a marginal contribution The results indicate that plasmonic gold NPs are well suited for

realndashtime monitoring of the corrosion kinetics of aluminum and its alloys in aqueous environment and in air

The technique is costndasheffective and can be carried out in the transmission or reflection configuration

19

Vertically Aligned Molybdenum Disulfide for Efficient Lithium Storage

Victor Shokhen1 Yana Miroshnikov1 Gregory Gershinsky1 Noam Gotlib2 Chen Stern2

Doron Naveh2 David Zitoun1 1Chemistry Nanotechnology and Advanced Materials (BINA) Bar-Ilan University

Ramat-Gan Israel 2Faculty of Engineering Bar-Ilan University Ramat-Gan Israel

Layered transition-metal disulfides (LTMDs) have played a prominent role in the development of electronic

energy conversion and storage devices Molybdenum disulfide (MoS2) has been widely investigated as a highly

efficient alternative to existing materials Most fabrication pathways of MoS2 focus on its planar growth on

various substrates to reach high-quality layers with planar orientation (PO) Nevertheless in most energy-

storage applications the most relevant orientation is the vertical alignment (VA) of well-defined layers VA

growth paves the way to highly dense devices with exposed active sites on the surface Here the chemical

vapor deposition (CVD) process has been investigated to grow 2H-MoS2 films hundreds of nanometers thick

with VA stacking The films show large domains of perfectly aligned layers with high crystallinity and density

and low surface roughness CVD-grown VA-MoS2 films show superior behavior in lithium storage with stable

capacity even at a high current density compared to PO-MoS2 films The VA-MoS2 films show a high

reversible capacity of 800 mAhg for lithium storage which corresponds to the full conversion to Mo and Li2S

HR-TEM images of VA-MoS2 Capacity of VA-MoS2 compare to PO-MoS2

20

Tailoring the Electronic Structure of TeY-doped NbBiO4 using Oxygen-

vacancy for All-oxide PV Application A Theoretical and Experimental Study

Vijay Singh Susanta Das David Keller Dan Thomas Major

Department of Chemistry Bar-Ilan University Ramat-Gan Israel

First principles studies of point defects and impurities in semiconductors insulators and metals have become an

integral part of material research over the last few decades1 Point defects and impurities often have decisive

effects on material properties2 3 Recently using density functional theory (DFT) calculations we have revealed

that Bi2O3 is a low band-gap material and the obtained energy band-gap 230 eV lies in the region of PV

interest The observed optical transitions between the valence band (VB) (O-2p states) and the conduction band

(CB) (Bi-6p states) are not allowed due to violation of the dipole selection rule (Δl =+-1) Therefore Bi2O3 is

not a potential absorber material for photovoltaic (PV) applications With the aid of DFT calculations and

experimental measurements we have also studied the NbBiO4 system extensively and our results revealed that

its valence band (VB) and conduction band (CB) consist of optically active states but its large energy band gap

350 eV puts a constraint on its use as an absorber material In the present talk I shall discuss how with the

help of suitable doping as well as oxygen vacancy we managed to reduce the energy band gap of NbBiO4 from

350 eV to 220 eV without changing its electronic structure The observed band-gap is in the region of PV

interest and transitions between the CB and VB states are optically allowed Using COHP (energy resolved

visualization of chemical bonding) calculations we revealed that Y doping in NbBiO4 significantly reduces the

covalent bonding between Bi and nearest neighbors oxygen ions from 100 eVbond to 010 eVbond As a

consequence the computed oxygen defect formation energies for Y-doped NbBiO4 system is lower than the

oxygen defect formation energies of the pure NbBiO4 system contributing to a large oxygen-defect

concentration Thus the significance of oxygen vacancy in Y-doped NbBiO4 (YBi site only) was revealed

and this study might serve to design better PV absorber materials in the future

References

1] Freysoldt C Grabowski B Hickel T Neugebauer J Kresse G Janotti A Van de Walle C G First-

principles calculations for point defects in solids Rev Mod Phys 2014 86 253-305

2] Ganguli N Dasgupta I Sanyal B Electronic structure and magnetism of transition metal doped Zn12O12

clusters Role of defects J Appl Phys 2010 108 123911

3] Yavo N Smith A D Yeheskel O Cohen S Korobko R Wachtel E Slater P R Lubomirsky I

Large Nonclassical Electrostriction in (Y Nb)‐ Stabilized δ‐ Bi2O3 Adv Funct Mater 2016

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

8

Stimuli-responsive Self-immolative Chemiluminescent Polymers

Samer Gnaim Doron Shabat

Organic Chemistry Tel Aviv University Tel Aviv Israel

Molecular probes based on 3-hydroxyphenyl-12-dioxetane chemiluminescence light emission are widely used

for various sensing and diagnostic applications (eg DNA enzymatic and chemical probes) Amplification of

molecular signals is an important task for the development of sensitive diagnostic probes in the field of

chemical sensing Recently various approaches have been introduced to increase the signal-to-noise ratio of

chemiluminescent light emission as a molecular signal

This work describes the design and synthesis of a new class of self-immolative chemiluminescent polymers

constructed of four complementary components ) chemically stable 12-dioxatene analog incorporated an

adamantyl group (bulky substituent) ii) protected 4-hydroxybenzyl alcohol substituent (self-immolative

monomeric linker) iii) a chemical or biological responsive group (eg silyl protecting group) and iv) the

monomers are linked together via carbonate linkage

Our results show that a single cleavage event of the protecting group on the phenol results in the formation of a

quinone derivative of 12-dioxetane which undergoes a rapid 16-elimination to release the leaving group on

the benzyl alcohol A nucleophilic attack on the benzylic-methide position initiates a chemically initiated

electron-exchange luminescence (CIEEL) process affording methyl benzoate and light emission

Using this new class of chemiluminescent polymers introduce the ability to design a novel stimuli responsive

chemilumnescent polymers as an amplification systems

9

Synthesis and Evaluation of NPP1 Inhibitors as Potential Drugs for the

Treatment of OsteoarthritisCPPD Disease

Molhm Nassir1 Shani Journo2 Abed Saady1 Uri Arad2 Bilha Fischer1 1Department of Chemistry Bar-Ilan University Ramat-Gan Israel

2Department of Rheumatology Tel Aviv Medical Center and the Faculty of Medicine Tel Aviv

Israel

Overproduction of extracellular pyrophosphate due to hydrolysis of ATP by NPP1 leads to deposition of

pathological Ca2P2O7H2O (CPPD) in cartilage resulting in a degenerative joint disease (CPPD disease) which

has no cure We explored the hypothesis that NPP1 inhibitors may be therapeutic agents for CPPD disease by

inhibiting the hydrolysis of ATP Specifically we synthesized novel analogs of ADP (an NPP1 substrate) in

which the Pab bridging oxygen atom is replaced by a methylene group and a derivative where both Pab

phosphate groups are replaced by sulfonate groups 1 and the Pb phosphate is replaced by a sulfonate isoster 2

In addition we synthesized an ADP analog in which the ribose ring was cleaved and the primary alcohol was

substituted by bis-phosphonate 3 To predict the ability of the derivatives to inhibit NPP1 we evaluated the

affinity and selectivity of the analogs to Zn2+ involved in NPP1rsquos catalytic activity We titrated the analogs with

Zn2+- or Ca2+ ions and monitored the titrations by UV Analogs 1 and 2 selectively coordinated Zn2+ and not

Ca2+ and formed ZnL2 complexes whereas analog 3 showed no affinity for Zn2+ and Ca2+ ions Next analogs

1 2 and 3 have been evaluated for their inhibitory effect on NPP1 in human chondrocytes Analog 3 proved to

be a promising inhibitor reducing NPPase activity in human chondrocytes by 90 at 100 microM vs analogs 1

and 2 (40 and 30 inhibition at 100 microM) Analogs 1 2 and 3 were found to be NPP selective showing no

activity at TNAP In summary analog 3 was found to be an effective and selective NPP1 inhibitor in human

chondrocytes Since analog 3 is a poor Zn2+-chelator we hypothesize that its inhibitory effect may be related to

its high flexibility at NPP1rsquos catalytic site

10

Evaluating the Peptide Structure Prediction Capabilities of a Purely Ab-Initio

Method

Moshe Goldstein13 Moshe Amitay2 1Department of Computer Science Jerusalem College of Technology Jerusalem Israel

2Department of Bioinformatics Jerusalem College of Technology Jerusalem Israel 3The Fritz Haber Research Center The Hebrew University of Jerusalem Jerusalem Israel

Peptides such as hormones and antibiotics play many biological functions Peptides` tertiary structures are of

paramount importance for understanding their function as well as the interactions with other molecules

DEEPSAM[1] (Diffusion Equation Evolutionary Programming Simulated Annealing Method) is a novel purely

ab-initio global optimization algorithm aimed to predict the structure of peptides and proteins from amino acid

sequence without any preliminary assumption This method is an Evolutionary Programming algorithm whose

mutation operators are built by hybridizing the advantages of three well-known optimization methods -

Diffusion Equation Method (DEM) Molecular Dynamics Simulated Annealing (MDSA) and the BFGS quasi-

Newton local minimization method

In principle DEEPSAM requires much less computing resources and is much faster than other structure

prediction methods such as Replica Exchange Molecular Dynamics (REMD) and therefore seems to be more

suitable for industrial use

The goal of this study has been to further evaluate the structure prediction accuracy of the DEEPSAM

algorithm by running it against a large number of known NMR structures of linear peptides (10-20 residues) in

an aqueous environment modeled by the GBSA implicit solvent model

[1] M Goldstein E Fredj and R B Gerber A New Hybrid Algorithm for Finding the Lowest Minima of

Potential Surfaces Approach and Applications to Peptides J of Computational Chemistry vol 32 pp 1785ndash

1800 (2011)

11

Keynote Lecture

Quantification of Polar Organic Reactivity

Herbert Mayr Department of Chemistry Ludwig-Maximilian-University Munich Muenchen Germany

The precision of quantum chemical calculations has reached a level that they can predict the thermodynamics of

organic reactions in the gas phase with an accuracy sometimes even exceeding that of experimental methods In

contrast calculations of reaction pathways in solution are still rather laborious and are predominantly used for

investigating mechanisms of known reactions rather than for designing new synthetic transformations For the

latter purpose linear free energy relationships are still indispensable tools Thus pKa values1 are often used for

estimating relative nucleophilic reactivities and leaving group abilities (nucleofugalities) of certain species A

limitation of these so-called Broslashnsted correlations is the fact that pKa values refer to interactions with the

proton while most reactions considered involve formation or cleavage of bonds to carbon We have therefore

developed a Lewis basicity scale2 with respect to C-centered Lewis acids (carbocations and electron-poor p-

systems) and discuss their correlations with nucleophilicities3 and nucleofugalities Analogous relationships

between Lewis acidities electrophilicities and electrofugalities will also be reported4

1) For a comprehensive collection of pKa values see httpibondnankaieducn

2) Mayr H Ammer J Baidya M Maji B Nigst T A Ofial A R Singer T Am Chem Soc

2015 137 2580minus2599

3) For a collection of nucleophilicity and electrophilicity parameters see

httpwwwcuplmudeocmayrDBintrohtml

4) Mayr H Ofial A R Chem Res 2016 49 952ndash965

12

Pyroelectricity from Non-Polar Crystals Enables Understanding Features of

Crystal Growth and Design

Meir Lahav Elena Meirzadeh Eran Mishuk David Ehre Igor Lubomirsky

Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Pyroelectricity a property of certain crystalline materials is the creation of a temporary surface charge upon

temperature change resulting in an external electric current Thermal movement of the molecules alters their

average positions leading to changes in their dipole moments As a consequence of this property spontaneous

polarization was constricted to the polar directions of the ten polar crystal classes when exposed to temperature

change resulting in the creation of two oppositely charged faces which engender pyroelectricity With the

emergence of modern analytical instruments for measuring electric currents it became possible however to

probe the structures of polar defects and imperfections and near surface polar layers that outline non-polar

crystals In spite of their slight amounts those architectures play indispensible role for the understanding of the

different features that control the macroscopic properties of crystals and provide perceptiveness on the

mechanisms of crystal growth

The following sub-topics will be presented

a) Deciphering the riddle of polarity found in the growth of the centrosymmetric crystals of glycine1-2

b) Enantiomeric disorder within the crystals of DL alanine not detectable by diffraction3

c) Solvent molecules as ldquotailor-maderdquo auxiliary in the control of crystal polymorphism as illustrated with the

three polymorphs of glycine4

d) Pyroelectricity combined with theoretical simulations as a new analytical method for the structure

determination of polar tiny-doped domains in crystals at the molecular level5

(1) Meirzadeh E Sapir L et al JACS 2016 138 14756

(2) Piperno S et al Angew Chem Int Ed 2013 52 6513

(3) Mishuk E et al Cryst Growth Des 2014 14 3839

(4) Meirzadeh E Dishon S work in progress

(5) Meirzadeh E Azuri I et al Nature Com 2016 7 13354

13

Enantioselective Synthesis of Intrinsically Chiral Nanocrystals

Gil Markovich Assaf Ben Moshe Uri Hananel

School of Chemistry Tel Aviv University Tel Aviv Israel

We have recently shown that it is possible to perform an enantioselective synthesis of inorganic nanostructures

made of intrinsically chiral crystals such as a-HgS Te and Se These crystals belonging to the P3121 (or

P3221) chiral space group were grown as nanocrystals in the presence of thiolated chiral molecules such as

cysteine penicillamine or glutathione This led to a preference in the growth of the nanocrystals towards a

certain handedness and consequent strong optical activity

Furthermore in the case of Te nanostructures particular synthesis conditions led to overall chiral shape of the

elongated nanostructures expressed as a twist on the scale of the size of the nanostructures of the order of 100

nm Finally the Te could be easily converted to other materials such as gold or silver telluride while

preserving the chiral shape opening the way to the formation of strongly optically active nanostructures made

of various plasmonic or semiconductor materials

We now demonstrate enantioselective synthesis of another class of materials Lanthanide phosphate hydrate

nanocrystals (also of chiral space group) in the presence of tartaric acid The formed nanocrystals exhibit

substantial degree of circularly polarized luminescence and their enantiomeric excess depends non-linearly on

the enantiomeric excess of the tartaric acid ligands We believe that this system may be useful for studying the

mechanism of enantioselection of the formed nanocrystal seeds in the presence of the chiral molecules

14

Optical Microcavity Devices Containing Organic Materials

Yaakov R Tischler Department of Chemistry Bar-Ilan University Ramat-Gan Israel

When two dielectric mirrors are positioned closely together a half wavelength apart or an integer multiple

thereof they form a Fabry-Peacuterot resonator that can trap light of a specific wavelength for many optical cycles

This resonant light trapping phenomenon is at the heart of vertical cavity surface emitting lasers (VCSELs)

optical switches resonant cavity LEDs and numerous other photonic and optoelectronic devices When organic

materials are situated inside such photonic structures and stability issues are properly addressed amazing

results can be achieved such as strong light-matter coupling at room temperature in both the visible and

infrared (IR) spectral ranges low threshold lasing and super-radiant coupling between molecules Using

microcavities properly designed for use with organics here we show strong light-matter coupling in the mid-IR

spectral range and the first demonstration of a monolayer VCSEL where the gain layer consists of a thin film

of fluorescent dye that is one molecule thick We motivate possible sensor applications for these devices and

discuss the unique physical photochemical and photoelectrochemical processes that can be investigated in

such structures

15

Keynote Lecture

Stability Study of Cation Moieties in Alkaline Anion Exchange Membranes for

Fuel Cell Applications

Dario Dekel1 Charles E Diesendruck2 1Chemical Engineering Technion - Israel Institute of Technology Haifa Israel

2Chemistry Technion - Israel Institute of Technology Haifa Israel

There is an increasing worldwide interest in anion exchange membrane fuel cells (AEMFCs) due to the

potential of this technology to use low cost electrocatalysts promising a considerable cost reduction for new

generation of fuel cell devices However the stability of anion conducting polymers for durable anion exchange

membranes (AEMs) and anion exchange ionomers (AEIs) is still a great concern

Here we present a novel methodology to measure the true alkaline stability of anion conducting polymers to be

used in AEMFCs The new ex-situ technique simulates the environment of an AEMFC during operation where

nucleophilic and basic OH- species in the absence or with scarce amount of water attack the functional groups

of the ionic polymer Using this technique we clearly show the critical effect of water molecules on the alkaline

stability of quaternary ammonium (QA) cations commonly used as functional groups in AEMFCs

The results show that as the water content is reduced the QA cations are more rapidly degraded in the presence

of OH- at room temperature With increasing number of water molecules solvating the hydroxide its

nucleophilicity and basicity are hindered and the QA degradation is significantly slowed These results indicate

that the currently used aqueous alkali ex-situ tests to measure AEM stability may lead to false positive stability

results where anion conducting polymers may appear more alkali stable than they really are

We strongly recommend the adoption of this novel developed technique to measure the true stability of anion

conducting polymers to be used for AEMFCs We believe that this new ex-situ protocol will rapidly lead to

development and selection of best stable polymers for durable and robust AEMFCs

16

Probing the Electrode-Electrolyte Interface in Rechargeable Batteries by Solid

State NMR

Michal Leskes Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Reactions at the electrode-electrolyte interface in lithium ion batteries play a key role in the batteryrsquos

performance and are one of the main causes for cell failure These reactions which lead to the formation of the

solid electrolyte interphase (SEI) ultimately control the reversibility of the cellrsquos Li chemistry and its kinetics

Thus an important part in the development of new high energy storage materials is control over their interfacial

chemistry and reactivity with the electrolyte Nuclear magnetic resonance (NMR) spectroscopy is an excellent

approach for following the formation of interfacial layers as it can detect disordered and heterogeneous phases

providing information on their chemical composition structure and dynamic properties Its main disadvantage

is its low sensitivity which is often a limiting factor when probing the SEI Here Irsquoll describe approaches to

overcome this sensitivity limitation by isotope enrichment as well as the potential of new hyperpolarization

techniques which can provide detailed molecular level insight into the chemistry of the SEI

17

First-Principles Based Studies of Complex Oxide Materials

Ilya Grinberg Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Since their first discovery over 70 years ago complex ferroelectric oxides have been shown to exhibit a wide

variety of physical and chemical properties that enable their use in a broad range of applications In particular

the dynamics in a class of complex ferroelectric solid solutions known as relaxors have been under

investigation due to their glass-like behavior and excellent technological properties Nevertheless despite over

50 years of research the key bonding motifs of relaxor ferroelectrics that give rise to their fascinating properties

such as ultrahigh piezoelectric coefficients high permittivity over a broad temperature range diffuse phase

transition without macroscopic lattice symmetry strong frequency dependence in dielectric response and

phonon anomalies are still subject to debate We use molecular dynamics simulations for the prototypical

Pb(Mg13Nb23)O3-PbTiO3 relaxor material to examine the structure bonding and the spatial and temporal

correlations of relaxors Our simulations show that the unusual properties of relaxors simply stem from the

presence of a multidomain state with an extremely small asymp2-10 nm domain size and that dynamics of relaxors

exhibit striking similarities to those of water arising from the local-environment dependent dipole decoupling

due to chemical bonding variation at particular atomic sites

Ferroelectric materials have also recently attracted increased attention as a candidate class of materials for use

in photovoltaic devices In a series of computational studies of a variety of ferroelectric perovskite oxides we

showed that the physical behaviors of these materials are governed by the simple local structure and chemical

bonding characteristics these can then be modified to rationally design new materials with light absorption

through the visible range that enables the use of these materials in photovoltaic applications

18

Colorimetric Detection of the Early Stages of Aluminum Oxidation Using

Plasmonic Gold NanondashIsland Films

Alexander Tesler1 Eyal Sabatani3 Takumi Sannomiya4 Yishai Feldman2

Alexander Vaskevich1 Israel Rubinstein1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemistry Division Nuclear Research Centre Negev Beer-Sheva Israel

4Materials Science amp Engineering Tokyo Institute of Technology Yokohama Kanagawa

Japan

Corrosion is a natural process of degradation of metallic parts reacting with their environment and is the major

cause of failure of metal structures inndashservice Hence detection of the early stages of environmental oxidation

of metal parts is of great importance Here we present a colorimetric method for monitoring the surface

conditions of aluminum using the localized surface plasmon resonance (LSPR) response of gold nanoparticles

(NPs) prendashdeposited onto the aluminum surface Upon oxidation metallic aluminum transforms to transparent

dielectric aluminum oxide (or hydroxide) In water the formed oxidation product adopts a twondashlayer structure

the bottom layer is thinner and compact while the top layer is thicker and highly porous The gold nanondashisland

layer initially deposited (by evaporationannealing) on the aluminum surface maintains its integrity after

corrosion in water and is located between the two aluminum oxide layers Water oxidation of aluminum

substrates with an overlayer of plasmonic gold nano-islands leads to a pronounced color change which can be

monitored in situ using reflection spectroscopy or colorimetrically by the naked eye Theoretical calculations

show that the major spectral change during corrosion is attributed to the interplay between plasmonic scattering

of the Au NP layer reacting to the changing environment and interference within the bottom aluminum oxide

layer acting as an etalon sandwiched between the Au islands and the underlying aluminum The top porous

oxide layer has only a marginal contribution The results indicate that plasmonic gold NPs are well suited for

realndashtime monitoring of the corrosion kinetics of aluminum and its alloys in aqueous environment and in air

The technique is costndasheffective and can be carried out in the transmission or reflection configuration

19

Vertically Aligned Molybdenum Disulfide for Efficient Lithium Storage

Victor Shokhen1 Yana Miroshnikov1 Gregory Gershinsky1 Noam Gotlib2 Chen Stern2

Doron Naveh2 David Zitoun1 1Chemistry Nanotechnology and Advanced Materials (BINA) Bar-Ilan University

Ramat-Gan Israel 2Faculty of Engineering Bar-Ilan University Ramat-Gan Israel

Layered transition-metal disulfides (LTMDs) have played a prominent role in the development of electronic

energy conversion and storage devices Molybdenum disulfide (MoS2) has been widely investigated as a highly

efficient alternative to existing materials Most fabrication pathways of MoS2 focus on its planar growth on

various substrates to reach high-quality layers with planar orientation (PO) Nevertheless in most energy-

storage applications the most relevant orientation is the vertical alignment (VA) of well-defined layers VA

growth paves the way to highly dense devices with exposed active sites on the surface Here the chemical

vapor deposition (CVD) process has been investigated to grow 2H-MoS2 films hundreds of nanometers thick

with VA stacking The films show large domains of perfectly aligned layers with high crystallinity and density

and low surface roughness CVD-grown VA-MoS2 films show superior behavior in lithium storage with stable

capacity even at a high current density compared to PO-MoS2 films The VA-MoS2 films show a high

reversible capacity of 800 mAhg for lithium storage which corresponds to the full conversion to Mo and Li2S

HR-TEM images of VA-MoS2 Capacity of VA-MoS2 compare to PO-MoS2

20

Tailoring the Electronic Structure of TeY-doped NbBiO4 using Oxygen-

vacancy for All-oxide PV Application A Theoretical and Experimental Study

Vijay Singh Susanta Das David Keller Dan Thomas Major

Department of Chemistry Bar-Ilan University Ramat-Gan Israel

First principles studies of point defects and impurities in semiconductors insulators and metals have become an

integral part of material research over the last few decades1 Point defects and impurities often have decisive

effects on material properties2 3 Recently using density functional theory (DFT) calculations we have revealed

that Bi2O3 is a low band-gap material and the obtained energy band-gap 230 eV lies in the region of PV

interest The observed optical transitions between the valence band (VB) (O-2p states) and the conduction band

(CB) (Bi-6p states) are not allowed due to violation of the dipole selection rule (Δl =+-1) Therefore Bi2O3 is

not a potential absorber material for photovoltaic (PV) applications With the aid of DFT calculations and

experimental measurements we have also studied the NbBiO4 system extensively and our results revealed that

its valence band (VB) and conduction band (CB) consist of optically active states but its large energy band gap

350 eV puts a constraint on its use as an absorber material In the present talk I shall discuss how with the

help of suitable doping as well as oxygen vacancy we managed to reduce the energy band gap of NbBiO4 from

350 eV to 220 eV without changing its electronic structure The observed band-gap is in the region of PV

interest and transitions between the CB and VB states are optically allowed Using COHP (energy resolved

visualization of chemical bonding) calculations we revealed that Y doping in NbBiO4 significantly reduces the

covalent bonding between Bi and nearest neighbors oxygen ions from 100 eVbond to 010 eVbond As a

consequence the computed oxygen defect formation energies for Y-doped NbBiO4 system is lower than the

oxygen defect formation energies of the pure NbBiO4 system contributing to a large oxygen-defect

concentration Thus the significance of oxygen vacancy in Y-doped NbBiO4 (YBi site only) was revealed

and this study might serve to design better PV absorber materials in the future

References

1] Freysoldt C Grabowski B Hickel T Neugebauer J Kresse G Janotti A Van de Walle C G First-

principles calculations for point defects in solids Rev Mod Phys 2014 86 253-305

2] Ganguli N Dasgupta I Sanyal B Electronic structure and magnetism of transition metal doped Zn12O12

clusters Role of defects J Appl Phys 2010 108 123911

3] Yavo N Smith A D Yeheskel O Cohen S Korobko R Wachtel E Slater P R Lubomirsky I

Large Nonclassical Electrostriction in (Y Nb)‐ Stabilized δ‐ Bi2O3 Adv Funct Mater 2016

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

9

Synthesis and Evaluation of NPP1 Inhibitors as Potential Drugs for the

Treatment of OsteoarthritisCPPD Disease

Molhm Nassir1 Shani Journo2 Abed Saady1 Uri Arad2 Bilha Fischer1 1Department of Chemistry Bar-Ilan University Ramat-Gan Israel

2Department of Rheumatology Tel Aviv Medical Center and the Faculty of Medicine Tel Aviv

Israel

Overproduction of extracellular pyrophosphate due to hydrolysis of ATP by NPP1 leads to deposition of

pathological Ca2P2O7H2O (CPPD) in cartilage resulting in a degenerative joint disease (CPPD disease) which

has no cure We explored the hypothesis that NPP1 inhibitors may be therapeutic agents for CPPD disease by

inhibiting the hydrolysis of ATP Specifically we synthesized novel analogs of ADP (an NPP1 substrate) in

which the Pab bridging oxygen atom is replaced by a methylene group and a derivative where both Pab

phosphate groups are replaced by sulfonate groups 1 and the Pb phosphate is replaced by a sulfonate isoster 2

In addition we synthesized an ADP analog in which the ribose ring was cleaved and the primary alcohol was

substituted by bis-phosphonate 3 To predict the ability of the derivatives to inhibit NPP1 we evaluated the

affinity and selectivity of the analogs to Zn2+ involved in NPP1rsquos catalytic activity We titrated the analogs with

Zn2+- or Ca2+ ions and monitored the titrations by UV Analogs 1 and 2 selectively coordinated Zn2+ and not

Ca2+ and formed ZnL2 complexes whereas analog 3 showed no affinity for Zn2+ and Ca2+ ions Next analogs

1 2 and 3 have been evaluated for their inhibitory effect on NPP1 in human chondrocytes Analog 3 proved to

be a promising inhibitor reducing NPPase activity in human chondrocytes by 90 at 100 microM vs analogs 1

and 2 (40 and 30 inhibition at 100 microM) Analogs 1 2 and 3 were found to be NPP selective showing no

activity at TNAP In summary analog 3 was found to be an effective and selective NPP1 inhibitor in human

chondrocytes Since analog 3 is a poor Zn2+-chelator we hypothesize that its inhibitory effect may be related to

its high flexibility at NPP1rsquos catalytic site

10

Evaluating the Peptide Structure Prediction Capabilities of a Purely Ab-Initio

Method

Moshe Goldstein13 Moshe Amitay2 1Department of Computer Science Jerusalem College of Technology Jerusalem Israel

2Department of Bioinformatics Jerusalem College of Technology Jerusalem Israel 3The Fritz Haber Research Center The Hebrew University of Jerusalem Jerusalem Israel

Peptides such as hormones and antibiotics play many biological functions Peptides` tertiary structures are of

paramount importance for understanding their function as well as the interactions with other molecules

DEEPSAM[1] (Diffusion Equation Evolutionary Programming Simulated Annealing Method) is a novel purely

ab-initio global optimization algorithm aimed to predict the structure of peptides and proteins from amino acid

sequence without any preliminary assumption This method is an Evolutionary Programming algorithm whose

mutation operators are built by hybridizing the advantages of three well-known optimization methods -

Diffusion Equation Method (DEM) Molecular Dynamics Simulated Annealing (MDSA) and the BFGS quasi-

Newton local minimization method

In principle DEEPSAM requires much less computing resources and is much faster than other structure

prediction methods such as Replica Exchange Molecular Dynamics (REMD) and therefore seems to be more

suitable for industrial use

The goal of this study has been to further evaluate the structure prediction accuracy of the DEEPSAM

algorithm by running it against a large number of known NMR structures of linear peptides (10-20 residues) in

an aqueous environment modeled by the GBSA implicit solvent model

[1] M Goldstein E Fredj and R B Gerber A New Hybrid Algorithm for Finding the Lowest Minima of

Potential Surfaces Approach and Applications to Peptides J of Computational Chemistry vol 32 pp 1785ndash

1800 (2011)

11

Keynote Lecture

Quantification of Polar Organic Reactivity

Herbert Mayr Department of Chemistry Ludwig-Maximilian-University Munich Muenchen Germany

The precision of quantum chemical calculations has reached a level that they can predict the thermodynamics of

organic reactions in the gas phase with an accuracy sometimes even exceeding that of experimental methods In

contrast calculations of reaction pathways in solution are still rather laborious and are predominantly used for

investigating mechanisms of known reactions rather than for designing new synthetic transformations For the

latter purpose linear free energy relationships are still indispensable tools Thus pKa values1 are often used for

estimating relative nucleophilic reactivities and leaving group abilities (nucleofugalities) of certain species A

limitation of these so-called Broslashnsted correlations is the fact that pKa values refer to interactions with the

proton while most reactions considered involve formation or cleavage of bonds to carbon We have therefore

developed a Lewis basicity scale2 with respect to C-centered Lewis acids (carbocations and electron-poor p-

systems) and discuss their correlations with nucleophilicities3 and nucleofugalities Analogous relationships

between Lewis acidities electrophilicities and electrofugalities will also be reported4

1) For a comprehensive collection of pKa values see httpibondnankaieducn

2) Mayr H Ammer J Baidya M Maji B Nigst T A Ofial A R Singer T Am Chem Soc

2015 137 2580minus2599

3) For a collection of nucleophilicity and electrophilicity parameters see

httpwwwcuplmudeocmayrDBintrohtml

4) Mayr H Ofial A R Chem Res 2016 49 952ndash965

12

Pyroelectricity from Non-Polar Crystals Enables Understanding Features of

Crystal Growth and Design

Meir Lahav Elena Meirzadeh Eran Mishuk David Ehre Igor Lubomirsky

Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Pyroelectricity a property of certain crystalline materials is the creation of a temporary surface charge upon

temperature change resulting in an external electric current Thermal movement of the molecules alters their

average positions leading to changes in their dipole moments As a consequence of this property spontaneous

polarization was constricted to the polar directions of the ten polar crystal classes when exposed to temperature

change resulting in the creation of two oppositely charged faces which engender pyroelectricity With the

emergence of modern analytical instruments for measuring electric currents it became possible however to

probe the structures of polar defects and imperfections and near surface polar layers that outline non-polar

crystals In spite of their slight amounts those architectures play indispensible role for the understanding of the

different features that control the macroscopic properties of crystals and provide perceptiveness on the

mechanisms of crystal growth

The following sub-topics will be presented

a) Deciphering the riddle of polarity found in the growth of the centrosymmetric crystals of glycine1-2

b) Enantiomeric disorder within the crystals of DL alanine not detectable by diffraction3

c) Solvent molecules as ldquotailor-maderdquo auxiliary in the control of crystal polymorphism as illustrated with the

three polymorphs of glycine4

d) Pyroelectricity combined with theoretical simulations as a new analytical method for the structure

determination of polar tiny-doped domains in crystals at the molecular level5

(1) Meirzadeh E Sapir L et al JACS 2016 138 14756

(2) Piperno S et al Angew Chem Int Ed 2013 52 6513

(3) Mishuk E et al Cryst Growth Des 2014 14 3839

(4) Meirzadeh E Dishon S work in progress

(5) Meirzadeh E Azuri I et al Nature Com 2016 7 13354

13

Enantioselective Synthesis of Intrinsically Chiral Nanocrystals

Gil Markovich Assaf Ben Moshe Uri Hananel

School of Chemistry Tel Aviv University Tel Aviv Israel

We have recently shown that it is possible to perform an enantioselective synthesis of inorganic nanostructures

made of intrinsically chiral crystals such as a-HgS Te and Se These crystals belonging to the P3121 (or

P3221) chiral space group were grown as nanocrystals in the presence of thiolated chiral molecules such as

cysteine penicillamine or glutathione This led to a preference in the growth of the nanocrystals towards a

certain handedness and consequent strong optical activity

Furthermore in the case of Te nanostructures particular synthesis conditions led to overall chiral shape of the

elongated nanostructures expressed as a twist on the scale of the size of the nanostructures of the order of 100

nm Finally the Te could be easily converted to other materials such as gold or silver telluride while

preserving the chiral shape opening the way to the formation of strongly optically active nanostructures made

of various plasmonic or semiconductor materials

We now demonstrate enantioselective synthesis of another class of materials Lanthanide phosphate hydrate

nanocrystals (also of chiral space group) in the presence of tartaric acid The formed nanocrystals exhibit

substantial degree of circularly polarized luminescence and their enantiomeric excess depends non-linearly on

the enantiomeric excess of the tartaric acid ligands We believe that this system may be useful for studying the

mechanism of enantioselection of the formed nanocrystal seeds in the presence of the chiral molecules

14

Optical Microcavity Devices Containing Organic Materials

Yaakov R Tischler Department of Chemistry Bar-Ilan University Ramat-Gan Israel

When two dielectric mirrors are positioned closely together a half wavelength apart or an integer multiple

thereof they form a Fabry-Peacuterot resonator that can trap light of a specific wavelength for many optical cycles

This resonant light trapping phenomenon is at the heart of vertical cavity surface emitting lasers (VCSELs)

optical switches resonant cavity LEDs and numerous other photonic and optoelectronic devices When organic

materials are situated inside such photonic structures and stability issues are properly addressed amazing

results can be achieved such as strong light-matter coupling at room temperature in both the visible and

infrared (IR) spectral ranges low threshold lasing and super-radiant coupling between molecules Using

microcavities properly designed for use with organics here we show strong light-matter coupling in the mid-IR

spectral range and the first demonstration of a monolayer VCSEL where the gain layer consists of a thin film

of fluorescent dye that is one molecule thick We motivate possible sensor applications for these devices and

discuss the unique physical photochemical and photoelectrochemical processes that can be investigated in

such structures

15

Keynote Lecture

Stability Study of Cation Moieties in Alkaline Anion Exchange Membranes for

Fuel Cell Applications

Dario Dekel1 Charles E Diesendruck2 1Chemical Engineering Technion - Israel Institute of Technology Haifa Israel

2Chemistry Technion - Israel Institute of Technology Haifa Israel

There is an increasing worldwide interest in anion exchange membrane fuel cells (AEMFCs) due to the

potential of this technology to use low cost electrocatalysts promising a considerable cost reduction for new

generation of fuel cell devices However the stability of anion conducting polymers for durable anion exchange

membranes (AEMs) and anion exchange ionomers (AEIs) is still a great concern

Here we present a novel methodology to measure the true alkaline stability of anion conducting polymers to be

used in AEMFCs The new ex-situ technique simulates the environment of an AEMFC during operation where

nucleophilic and basic OH- species in the absence or with scarce amount of water attack the functional groups

of the ionic polymer Using this technique we clearly show the critical effect of water molecules on the alkaline

stability of quaternary ammonium (QA) cations commonly used as functional groups in AEMFCs

The results show that as the water content is reduced the QA cations are more rapidly degraded in the presence

of OH- at room temperature With increasing number of water molecules solvating the hydroxide its

nucleophilicity and basicity are hindered and the QA degradation is significantly slowed These results indicate

that the currently used aqueous alkali ex-situ tests to measure AEM stability may lead to false positive stability

results where anion conducting polymers may appear more alkali stable than they really are

We strongly recommend the adoption of this novel developed technique to measure the true stability of anion

conducting polymers to be used for AEMFCs We believe that this new ex-situ protocol will rapidly lead to

development and selection of best stable polymers for durable and robust AEMFCs

16

Probing the Electrode-Electrolyte Interface in Rechargeable Batteries by Solid

State NMR

Michal Leskes Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Reactions at the electrode-electrolyte interface in lithium ion batteries play a key role in the batteryrsquos

performance and are one of the main causes for cell failure These reactions which lead to the formation of the

solid electrolyte interphase (SEI) ultimately control the reversibility of the cellrsquos Li chemistry and its kinetics

Thus an important part in the development of new high energy storage materials is control over their interfacial

chemistry and reactivity with the electrolyte Nuclear magnetic resonance (NMR) spectroscopy is an excellent

approach for following the formation of interfacial layers as it can detect disordered and heterogeneous phases

providing information on their chemical composition structure and dynamic properties Its main disadvantage

is its low sensitivity which is often a limiting factor when probing the SEI Here Irsquoll describe approaches to

overcome this sensitivity limitation by isotope enrichment as well as the potential of new hyperpolarization

techniques which can provide detailed molecular level insight into the chemistry of the SEI

17

First-Principles Based Studies of Complex Oxide Materials

Ilya Grinberg Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Since their first discovery over 70 years ago complex ferroelectric oxides have been shown to exhibit a wide

variety of physical and chemical properties that enable their use in a broad range of applications In particular

the dynamics in a class of complex ferroelectric solid solutions known as relaxors have been under

investigation due to their glass-like behavior and excellent technological properties Nevertheless despite over

50 years of research the key bonding motifs of relaxor ferroelectrics that give rise to their fascinating properties

such as ultrahigh piezoelectric coefficients high permittivity over a broad temperature range diffuse phase

transition without macroscopic lattice symmetry strong frequency dependence in dielectric response and

phonon anomalies are still subject to debate We use molecular dynamics simulations for the prototypical

Pb(Mg13Nb23)O3-PbTiO3 relaxor material to examine the structure bonding and the spatial and temporal

correlations of relaxors Our simulations show that the unusual properties of relaxors simply stem from the

presence of a multidomain state with an extremely small asymp2-10 nm domain size and that dynamics of relaxors

exhibit striking similarities to those of water arising from the local-environment dependent dipole decoupling

due to chemical bonding variation at particular atomic sites

Ferroelectric materials have also recently attracted increased attention as a candidate class of materials for use

in photovoltaic devices In a series of computational studies of a variety of ferroelectric perovskite oxides we

showed that the physical behaviors of these materials are governed by the simple local structure and chemical

bonding characteristics these can then be modified to rationally design new materials with light absorption

through the visible range that enables the use of these materials in photovoltaic applications

18

Colorimetric Detection of the Early Stages of Aluminum Oxidation Using

Plasmonic Gold NanondashIsland Films

Alexander Tesler1 Eyal Sabatani3 Takumi Sannomiya4 Yishai Feldman2

Alexander Vaskevich1 Israel Rubinstein1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemistry Division Nuclear Research Centre Negev Beer-Sheva Israel

4Materials Science amp Engineering Tokyo Institute of Technology Yokohama Kanagawa

Japan

Corrosion is a natural process of degradation of metallic parts reacting with their environment and is the major

cause of failure of metal structures inndashservice Hence detection of the early stages of environmental oxidation

of metal parts is of great importance Here we present a colorimetric method for monitoring the surface

conditions of aluminum using the localized surface plasmon resonance (LSPR) response of gold nanoparticles

(NPs) prendashdeposited onto the aluminum surface Upon oxidation metallic aluminum transforms to transparent

dielectric aluminum oxide (or hydroxide) In water the formed oxidation product adopts a twondashlayer structure

the bottom layer is thinner and compact while the top layer is thicker and highly porous The gold nanondashisland

layer initially deposited (by evaporationannealing) on the aluminum surface maintains its integrity after

corrosion in water and is located between the two aluminum oxide layers Water oxidation of aluminum

substrates with an overlayer of plasmonic gold nano-islands leads to a pronounced color change which can be

monitored in situ using reflection spectroscopy or colorimetrically by the naked eye Theoretical calculations

show that the major spectral change during corrosion is attributed to the interplay between plasmonic scattering

of the Au NP layer reacting to the changing environment and interference within the bottom aluminum oxide

layer acting as an etalon sandwiched between the Au islands and the underlying aluminum The top porous

oxide layer has only a marginal contribution The results indicate that plasmonic gold NPs are well suited for

realndashtime monitoring of the corrosion kinetics of aluminum and its alloys in aqueous environment and in air

The technique is costndasheffective and can be carried out in the transmission or reflection configuration

19

Vertically Aligned Molybdenum Disulfide for Efficient Lithium Storage

Victor Shokhen1 Yana Miroshnikov1 Gregory Gershinsky1 Noam Gotlib2 Chen Stern2

Doron Naveh2 David Zitoun1 1Chemistry Nanotechnology and Advanced Materials (BINA) Bar-Ilan University

Ramat-Gan Israel 2Faculty of Engineering Bar-Ilan University Ramat-Gan Israel

Layered transition-metal disulfides (LTMDs) have played a prominent role in the development of electronic

energy conversion and storage devices Molybdenum disulfide (MoS2) has been widely investigated as a highly

efficient alternative to existing materials Most fabrication pathways of MoS2 focus on its planar growth on

various substrates to reach high-quality layers with planar orientation (PO) Nevertheless in most energy-

storage applications the most relevant orientation is the vertical alignment (VA) of well-defined layers VA

growth paves the way to highly dense devices with exposed active sites on the surface Here the chemical

vapor deposition (CVD) process has been investigated to grow 2H-MoS2 films hundreds of nanometers thick

with VA stacking The films show large domains of perfectly aligned layers with high crystallinity and density

and low surface roughness CVD-grown VA-MoS2 films show superior behavior in lithium storage with stable

capacity even at a high current density compared to PO-MoS2 films The VA-MoS2 films show a high

reversible capacity of 800 mAhg for lithium storage which corresponds to the full conversion to Mo and Li2S

HR-TEM images of VA-MoS2 Capacity of VA-MoS2 compare to PO-MoS2

20

Tailoring the Electronic Structure of TeY-doped NbBiO4 using Oxygen-

vacancy for All-oxide PV Application A Theoretical and Experimental Study

Vijay Singh Susanta Das David Keller Dan Thomas Major

Department of Chemistry Bar-Ilan University Ramat-Gan Israel

First principles studies of point defects and impurities in semiconductors insulators and metals have become an

integral part of material research over the last few decades1 Point defects and impurities often have decisive

effects on material properties2 3 Recently using density functional theory (DFT) calculations we have revealed

that Bi2O3 is a low band-gap material and the obtained energy band-gap 230 eV lies in the region of PV

interest The observed optical transitions between the valence band (VB) (O-2p states) and the conduction band

(CB) (Bi-6p states) are not allowed due to violation of the dipole selection rule (Δl =+-1) Therefore Bi2O3 is

not a potential absorber material for photovoltaic (PV) applications With the aid of DFT calculations and

experimental measurements we have also studied the NbBiO4 system extensively and our results revealed that

its valence band (VB) and conduction band (CB) consist of optically active states but its large energy band gap

350 eV puts a constraint on its use as an absorber material In the present talk I shall discuss how with the

help of suitable doping as well as oxygen vacancy we managed to reduce the energy band gap of NbBiO4 from

350 eV to 220 eV without changing its electronic structure The observed band-gap is in the region of PV

interest and transitions between the CB and VB states are optically allowed Using COHP (energy resolved

visualization of chemical bonding) calculations we revealed that Y doping in NbBiO4 significantly reduces the

covalent bonding between Bi and nearest neighbors oxygen ions from 100 eVbond to 010 eVbond As a

consequence the computed oxygen defect formation energies for Y-doped NbBiO4 system is lower than the

oxygen defect formation energies of the pure NbBiO4 system contributing to a large oxygen-defect

concentration Thus the significance of oxygen vacancy in Y-doped NbBiO4 (YBi site only) was revealed

and this study might serve to design better PV absorber materials in the future

References

1] Freysoldt C Grabowski B Hickel T Neugebauer J Kresse G Janotti A Van de Walle C G First-

principles calculations for point defects in solids Rev Mod Phys 2014 86 253-305

2] Ganguli N Dasgupta I Sanyal B Electronic structure and magnetism of transition metal doped Zn12O12

clusters Role of defects J Appl Phys 2010 108 123911

3] Yavo N Smith A D Yeheskel O Cohen S Korobko R Wachtel E Slater P R Lubomirsky I

Large Nonclassical Electrostriction in (Y Nb)‐ Stabilized δ‐ Bi2O3 Adv Funct Mater 2016

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

10

Evaluating the Peptide Structure Prediction Capabilities of a Purely Ab-Initio

Method

Moshe Goldstein13 Moshe Amitay2 1Department of Computer Science Jerusalem College of Technology Jerusalem Israel

2Department of Bioinformatics Jerusalem College of Technology Jerusalem Israel 3The Fritz Haber Research Center The Hebrew University of Jerusalem Jerusalem Israel

Peptides such as hormones and antibiotics play many biological functions Peptides` tertiary structures are of

paramount importance for understanding their function as well as the interactions with other molecules

DEEPSAM[1] (Diffusion Equation Evolutionary Programming Simulated Annealing Method) is a novel purely

ab-initio global optimization algorithm aimed to predict the structure of peptides and proteins from amino acid

sequence without any preliminary assumption This method is an Evolutionary Programming algorithm whose

mutation operators are built by hybridizing the advantages of three well-known optimization methods -

Diffusion Equation Method (DEM) Molecular Dynamics Simulated Annealing (MDSA) and the BFGS quasi-

Newton local minimization method

In principle DEEPSAM requires much less computing resources and is much faster than other structure

prediction methods such as Replica Exchange Molecular Dynamics (REMD) and therefore seems to be more

suitable for industrial use

The goal of this study has been to further evaluate the structure prediction accuracy of the DEEPSAM

algorithm by running it against a large number of known NMR structures of linear peptides (10-20 residues) in

an aqueous environment modeled by the GBSA implicit solvent model

[1] M Goldstein E Fredj and R B Gerber A New Hybrid Algorithm for Finding the Lowest Minima of

Potential Surfaces Approach and Applications to Peptides J of Computational Chemistry vol 32 pp 1785ndash

1800 (2011)

11

Keynote Lecture

Quantification of Polar Organic Reactivity

Herbert Mayr Department of Chemistry Ludwig-Maximilian-University Munich Muenchen Germany

The precision of quantum chemical calculations has reached a level that they can predict the thermodynamics of

organic reactions in the gas phase with an accuracy sometimes even exceeding that of experimental methods In

contrast calculations of reaction pathways in solution are still rather laborious and are predominantly used for

investigating mechanisms of known reactions rather than for designing new synthetic transformations For the

latter purpose linear free energy relationships are still indispensable tools Thus pKa values1 are often used for

estimating relative nucleophilic reactivities and leaving group abilities (nucleofugalities) of certain species A

limitation of these so-called Broslashnsted correlations is the fact that pKa values refer to interactions with the

proton while most reactions considered involve formation or cleavage of bonds to carbon We have therefore

developed a Lewis basicity scale2 with respect to C-centered Lewis acids (carbocations and electron-poor p-

systems) and discuss their correlations with nucleophilicities3 and nucleofugalities Analogous relationships

between Lewis acidities electrophilicities and electrofugalities will also be reported4

1) For a comprehensive collection of pKa values see httpibondnankaieducn

2) Mayr H Ammer J Baidya M Maji B Nigst T A Ofial A R Singer T Am Chem Soc

2015 137 2580minus2599

3) For a collection of nucleophilicity and electrophilicity parameters see

httpwwwcuplmudeocmayrDBintrohtml

4) Mayr H Ofial A R Chem Res 2016 49 952ndash965

12

Pyroelectricity from Non-Polar Crystals Enables Understanding Features of

Crystal Growth and Design

Meir Lahav Elena Meirzadeh Eran Mishuk David Ehre Igor Lubomirsky

Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Pyroelectricity a property of certain crystalline materials is the creation of a temporary surface charge upon

temperature change resulting in an external electric current Thermal movement of the molecules alters their

average positions leading to changes in their dipole moments As a consequence of this property spontaneous

polarization was constricted to the polar directions of the ten polar crystal classes when exposed to temperature

change resulting in the creation of two oppositely charged faces which engender pyroelectricity With the

emergence of modern analytical instruments for measuring electric currents it became possible however to

probe the structures of polar defects and imperfections and near surface polar layers that outline non-polar

crystals In spite of their slight amounts those architectures play indispensible role for the understanding of the

different features that control the macroscopic properties of crystals and provide perceptiveness on the

mechanisms of crystal growth

The following sub-topics will be presented

a) Deciphering the riddle of polarity found in the growth of the centrosymmetric crystals of glycine1-2

b) Enantiomeric disorder within the crystals of DL alanine not detectable by diffraction3

c) Solvent molecules as ldquotailor-maderdquo auxiliary in the control of crystal polymorphism as illustrated with the

three polymorphs of glycine4

d) Pyroelectricity combined with theoretical simulations as a new analytical method for the structure

determination of polar tiny-doped domains in crystals at the molecular level5

(1) Meirzadeh E Sapir L et al JACS 2016 138 14756

(2) Piperno S et al Angew Chem Int Ed 2013 52 6513

(3) Mishuk E et al Cryst Growth Des 2014 14 3839

(4) Meirzadeh E Dishon S work in progress

(5) Meirzadeh E Azuri I et al Nature Com 2016 7 13354

13

Enantioselective Synthesis of Intrinsically Chiral Nanocrystals

Gil Markovich Assaf Ben Moshe Uri Hananel

School of Chemistry Tel Aviv University Tel Aviv Israel

We have recently shown that it is possible to perform an enantioselective synthesis of inorganic nanostructures

made of intrinsically chiral crystals such as a-HgS Te and Se These crystals belonging to the P3121 (or

P3221) chiral space group were grown as nanocrystals in the presence of thiolated chiral molecules such as

cysteine penicillamine or glutathione This led to a preference in the growth of the nanocrystals towards a

certain handedness and consequent strong optical activity

Furthermore in the case of Te nanostructures particular synthesis conditions led to overall chiral shape of the

elongated nanostructures expressed as a twist on the scale of the size of the nanostructures of the order of 100

nm Finally the Te could be easily converted to other materials such as gold or silver telluride while

preserving the chiral shape opening the way to the formation of strongly optically active nanostructures made

of various plasmonic or semiconductor materials

We now demonstrate enantioselective synthesis of another class of materials Lanthanide phosphate hydrate

nanocrystals (also of chiral space group) in the presence of tartaric acid The formed nanocrystals exhibit

substantial degree of circularly polarized luminescence and their enantiomeric excess depends non-linearly on

the enantiomeric excess of the tartaric acid ligands We believe that this system may be useful for studying the

mechanism of enantioselection of the formed nanocrystal seeds in the presence of the chiral molecules

14

Optical Microcavity Devices Containing Organic Materials

Yaakov R Tischler Department of Chemistry Bar-Ilan University Ramat-Gan Israel

When two dielectric mirrors are positioned closely together a half wavelength apart or an integer multiple

thereof they form a Fabry-Peacuterot resonator that can trap light of a specific wavelength for many optical cycles

This resonant light trapping phenomenon is at the heart of vertical cavity surface emitting lasers (VCSELs)

optical switches resonant cavity LEDs and numerous other photonic and optoelectronic devices When organic

materials are situated inside such photonic structures and stability issues are properly addressed amazing

results can be achieved such as strong light-matter coupling at room temperature in both the visible and

infrared (IR) spectral ranges low threshold lasing and super-radiant coupling between molecules Using

microcavities properly designed for use with organics here we show strong light-matter coupling in the mid-IR

spectral range and the first demonstration of a monolayer VCSEL where the gain layer consists of a thin film

of fluorescent dye that is one molecule thick We motivate possible sensor applications for these devices and

discuss the unique physical photochemical and photoelectrochemical processes that can be investigated in

such structures

15

Keynote Lecture

Stability Study of Cation Moieties in Alkaline Anion Exchange Membranes for

Fuel Cell Applications

Dario Dekel1 Charles E Diesendruck2 1Chemical Engineering Technion - Israel Institute of Technology Haifa Israel

2Chemistry Technion - Israel Institute of Technology Haifa Israel

There is an increasing worldwide interest in anion exchange membrane fuel cells (AEMFCs) due to the

potential of this technology to use low cost electrocatalysts promising a considerable cost reduction for new

generation of fuel cell devices However the stability of anion conducting polymers for durable anion exchange

membranes (AEMs) and anion exchange ionomers (AEIs) is still a great concern

Here we present a novel methodology to measure the true alkaline stability of anion conducting polymers to be

used in AEMFCs The new ex-situ technique simulates the environment of an AEMFC during operation where

nucleophilic and basic OH- species in the absence or with scarce amount of water attack the functional groups

of the ionic polymer Using this technique we clearly show the critical effect of water molecules on the alkaline

stability of quaternary ammonium (QA) cations commonly used as functional groups in AEMFCs

The results show that as the water content is reduced the QA cations are more rapidly degraded in the presence

of OH- at room temperature With increasing number of water molecules solvating the hydroxide its

nucleophilicity and basicity are hindered and the QA degradation is significantly slowed These results indicate

that the currently used aqueous alkali ex-situ tests to measure AEM stability may lead to false positive stability

results where anion conducting polymers may appear more alkali stable than they really are

We strongly recommend the adoption of this novel developed technique to measure the true stability of anion

conducting polymers to be used for AEMFCs We believe that this new ex-situ protocol will rapidly lead to

development and selection of best stable polymers for durable and robust AEMFCs

16

Probing the Electrode-Electrolyte Interface in Rechargeable Batteries by Solid

State NMR

Michal Leskes Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Reactions at the electrode-electrolyte interface in lithium ion batteries play a key role in the batteryrsquos

performance and are one of the main causes for cell failure These reactions which lead to the formation of the

solid electrolyte interphase (SEI) ultimately control the reversibility of the cellrsquos Li chemistry and its kinetics

Thus an important part in the development of new high energy storage materials is control over their interfacial

chemistry and reactivity with the electrolyte Nuclear magnetic resonance (NMR) spectroscopy is an excellent

approach for following the formation of interfacial layers as it can detect disordered and heterogeneous phases

providing information on their chemical composition structure and dynamic properties Its main disadvantage

is its low sensitivity which is often a limiting factor when probing the SEI Here Irsquoll describe approaches to

overcome this sensitivity limitation by isotope enrichment as well as the potential of new hyperpolarization

techniques which can provide detailed molecular level insight into the chemistry of the SEI

17

First-Principles Based Studies of Complex Oxide Materials

Ilya Grinberg Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Since their first discovery over 70 years ago complex ferroelectric oxides have been shown to exhibit a wide

variety of physical and chemical properties that enable their use in a broad range of applications In particular

the dynamics in a class of complex ferroelectric solid solutions known as relaxors have been under

investigation due to their glass-like behavior and excellent technological properties Nevertheless despite over

50 years of research the key bonding motifs of relaxor ferroelectrics that give rise to their fascinating properties

such as ultrahigh piezoelectric coefficients high permittivity over a broad temperature range diffuse phase

transition without macroscopic lattice symmetry strong frequency dependence in dielectric response and

phonon anomalies are still subject to debate We use molecular dynamics simulations for the prototypical

Pb(Mg13Nb23)O3-PbTiO3 relaxor material to examine the structure bonding and the spatial and temporal

correlations of relaxors Our simulations show that the unusual properties of relaxors simply stem from the

presence of a multidomain state with an extremely small asymp2-10 nm domain size and that dynamics of relaxors

exhibit striking similarities to those of water arising from the local-environment dependent dipole decoupling

due to chemical bonding variation at particular atomic sites

Ferroelectric materials have also recently attracted increased attention as a candidate class of materials for use

in photovoltaic devices In a series of computational studies of a variety of ferroelectric perovskite oxides we

showed that the physical behaviors of these materials are governed by the simple local structure and chemical

bonding characteristics these can then be modified to rationally design new materials with light absorption

through the visible range that enables the use of these materials in photovoltaic applications

18

Colorimetric Detection of the Early Stages of Aluminum Oxidation Using

Plasmonic Gold NanondashIsland Films

Alexander Tesler1 Eyal Sabatani3 Takumi Sannomiya4 Yishai Feldman2

Alexander Vaskevich1 Israel Rubinstein1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemistry Division Nuclear Research Centre Negev Beer-Sheva Israel

4Materials Science amp Engineering Tokyo Institute of Technology Yokohama Kanagawa

Japan

Corrosion is a natural process of degradation of metallic parts reacting with their environment and is the major

cause of failure of metal structures inndashservice Hence detection of the early stages of environmental oxidation

of metal parts is of great importance Here we present a colorimetric method for monitoring the surface

conditions of aluminum using the localized surface plasmon resonance (LSPR) response of gold nanoparticles

(NPs) prendashdeposited onto the aluminum surface Upon oxidation metallic aluminum transforms to transparent

dielectric aluminum oxide (or hydroxide) In water the formed oxidation product adopts a twondashlayer structure

the bottom layer is thinner and compact while the top layer is thicker and highly porous The gold nanondashisland

layer initially deposited (by evaporationannealing) on the aluminum surface maintains its integrity after

corrosion in water and is located between the two aluminum oxide layers Water oxidation of aluminum

substrates with an overlayer of plasmonic gold nano-islands leads to a pronounced color change which can be

monitored in situ using reflection spectroscopy or colorimetrically by the naked eye Theoretical calculations

show that the major spectral change during corrosion is attributed to the interplay between plasmonic scattering

of the Au NP layer reacting to the changing environment and interference within the bottom aluminum oxide

layer acting as an etalon sandwiched between the Au islands and the underlying aluminum The top porous

oxide layer has only a marginal contribution The results indicate that plasmonic gold NPs are well suited for

realndashtime monitoring of the corrosion kinetics of aluminum and its alloys in aqueous environment and in air

The technique is costndasheffective and can be carried out in the transmission or reflection configuration

19

Vertically Aligned Molybdenum Disulfide for Efficient Lithium Storage

Victor Shokhen1 Yana Miroshnikov1 Gregory Gershinsky1 Noam Gotlib2 Chen Stern2

Doron Naveh2 David Zitoun1 1Chemistry Nanotechnology and Advanced Materials (BINA) Bar-Ilan University

Ramat-Gan Israel 2Faculty of Engineering Bar-Ilan University Ramat-Gan Israel

Layered transition-metal disulfides (LTMDs) have played a prominent role in the development of electronic

energy conversion and storage devices Molybdenum disulfide (MoS2) has been widely investigated as a highly

efficient alternative to existing materials Most fabrication pathways of MoS2 focus on its planar growth on

various substrates to reach high-quality layers with planar orientation (PO) Nevertheless in most energy-

storage applications the most relevant orientation is the vertical alignment (VA) of well-defined layers VA

growth paves the way to highly dense devices with exposed active sites on the surface Here the chemical

vapor deposition (CVD) process has been investigated to grow 2H-MoS2 films hundreds of nanometers thick

with VA stacking The films show large domains of perfectly aligned layers with high crystallinity and density

and low surface roughness CVD-grown VA-MoS2 films show superior behavior in lithium storage with stable

capacity even at a high current density compared to PO-MoS2 films The VA-MoS2 films show a high

reversible capacity of 800 mAhg for lithium storage which corresponds to the full conversion to Mo and Li2S

HR-TEM images of VA-MoS2 Capacity of VA-MoS2 compare to PO-MoS2

20

Tailoring the Electronic Structure of TeY-doped NbBiO4 using Oxygen-

vacancy for All-oxide PV Application A Theoretical and Experimental Study

Vijay Singh Susanta Das David Keller Dan Thomas Major

Department of Chemistry Bar-Ilan University Ramat-Gan Israel

First principles studies of point defects and impurities in semiconductors insulators and metals have become an

integral part of material research over the last few decades1 Point defects and impurities often have decisive

effects on material properties2 3 Recently using density functional theory (DFT) calculations we have revealed

that Bi2O3 is a low band-gap material and the obtained energy band-gap 230 eV lies in the region of PV

interest The observed optical transitions between the valence band (VB) (O-2p states) and the conduction band

(CB) (Bi-6p states) are not allowed due to violation of the dipole selection rule (Δl =+-1) Therefore Bi2O3 is

not a potential absorber material for photovoltaic (PV) applications With the aid of DFT calculations and

experimental measurements we have also studied the NbBiO4 system extensively and our results revealed that

its valence band (VB) and conduction band (CB) consist of optically active states but its large energy band gap

350 eV puts a constraint on its use as an absorber material In the present talk I shall discuss how with the

help of suitable doping as well as oxygen vacancy we managed to reduce the energy band gap of NbBiO4 from

350 eV to 220 eV without changing its electronic structure The observed band-gap is in the region of PV

interest and transitions between the CB and VB states are optically allowed Using COHP (energy resolved

visualization of chemical bonding) calculations we revealed that Y doping in NbBiO4 significantly reduces the

covalent bonding between Bi and nearest neighbors oxygen ions from 100 eVbond to 010 eVbond As a

consequence the computed oxygen defect formation energies for Y-doped NbBiO4 system is lower than the

oxygen defect formation energies of the pure NbBiO4 system contributing to a large oxygen-defect

concentration Thus the significance of oxygen vacancy in Y-doped NbBiO4 (YBi site only) was revealed

and this study might serve to design better PV absorber materials in the future

References

1] Freysoldt C Grabowski B Hickel T Neugebauer J Kresse G Janotti A Van de Walle C G First-

principles calculations for point defects in solids Rev Mod Phys 2014 86 253-305

2] Ganguli N Dasgupta I Sanyal B Electronic structure and magnetism of transition metal doped Zn12O12

clusters Role of defects J Appl Phys 2010 108 123911

3] Yavo N Smith A D Yeheskel O Cohen S Korobko R Wachtel E Slater P R Lubomirsky I

Large Nonclassical Electrostriction in (Y Nb)‐ Stabilized δ‐ Bi2O3 Adv Funct Mater 2016

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

11

Keynote Lecture

Quantification of Polar Organic Reactivity

Herbert Mayr Department of Chemistry Ludwig-Maximilian-University Munich Muenchen Germany

The precision of quantum chemical calculations has reached a level that they can predict the thermodynamics of

organic reactions in the gas phase with an accuracy sometimes even exceeding that of experimental methods In

contrast calculations of reaction pathways in solution are still rather laborious and are predominantly used for

investigating mechanisms of known reactions rather than for designing new synthetic transformations For the

latter purpose linear free energy relationships are still indispensable tools Thus pKa values1 are often used for

estimating relative nucleophilic reactivities and leaving group abilities (nucleofugalities) of certain species A

limitation of these so-called Broslashnsted correlations is the fact that pKa values refer to interactions with the

proton while most reactions considered involve formation or cleavage of bonds to carbon We have therefore

developed a Lewis basicity scale2 with respect to C-centered Lewis acids (carbocations and electron-poor p-

systems) and discuss their correlations with nucleophilicities3 and nucleofugalities Analogous relationships

between Lewis acidities electrophilicities and electrofugalities will also be reported4

1) For a comprehensive collection of pKa values see httpibondnankaieducn

2) Mayr H Ammer J Baidya M Maji B Nigst T A Ofial A R Singer T Am Chem Soc

2015 137 2580minus2599

3) For a collection of nucleophilicity and electrophilicity parameters see

httpwwwcuplmudeocmayrDBintrohtml

4) Mayr H Ofial A R Chem Res 2016 49 952ndash965

12

Pyroelectricity from Non-Polar Crystals Enables Understanding Features of

Crystal Growth and Design

Meir Lahav Elena Meirzadeh Eran Mishuk David Ehre Igor Lubomirsky

Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Pyroelectricity a property of certain crystalline materials is the creation of a temporary surface charge upon

temperature change resulting in an external electric current Thermal movement of the molecules alters their

average positions leading to changes in their dipole moments As a consequence of this property spontaneous

polarization was constricted to the polar directions of the ten polar crystal classes when exposed to temperature

change resulting in the creation of two oppositely charged faces which engender pyroelectricity With the

emergence of modern analytical instruments for measuring electric currents it became possible however to

probe the structures of polar defects and imperfections and near surface polar layers that outline non-polar

crystals In spite of their slight amounts those architectures play indispensible role for the understanding of the

different features that control the macroscopic properties of crystals and provide perceptiveness on the

mechanisms of crystal growth

The following sub-topics will be presented

a) Deciphering the riddle of polarity found in the growth of the centrosymmetric crystals of glycine1-2

b) Enantiomeric disorder within the crystals of DL alanine not detectable by diffraction3

c) Solvent molecules as ldquotailor-maderdquo auxiliary in the control of crystal polymorphism as illustrated with the

three polymorphs of glycine4

d) Pyroelectricity combined with theoretical simulations as a new analytical method for the structure

determination of polar tiny-doped domains in crystals at the molecular level5

(1) Meirzadeh E Sapir L et al JACS 2016 138 14756

(2) Piperno S et al Angew Chem Int Ed 2013 52 6513

(3) Mishuk E et al Cryst Growth Des 2014 14 3839

(4) Meirzadeh E Dishon S work in progress

(5) Meirzadeh E Azuri I et al Nature Com 2016 7 13354

13

Enantioselective Synthesis of Intrinsically Chiral Nanocrystals

Gil Markovich Assaf Ben Moshe Uri Hananel

School of Chemistry Tel Aviv University Tel Aviv Israel

We have recently shown that it is possible to perform an enantioselective synthesis of inorganic nanostructures

made of intrinsically chiral crystals such as a-HgS Te and Se These crystals belonging to the P3121 (or

P3221) chiral space group were grown as nanocrystals in the presence of thiolated chiral molecules such as

cysteine penicillamine or glutathione This led to a preference in the growth of the nanocrystals towards a

certain handedness and consequent strong optical activity

Furthermore in the case of Te nanostructures particular synthesis conditions led to overall chiral shape of the

elongated nanostructures expressed as a twist on the scale of the size of the nanostructures of the order of 100

nm Finally the Te could be easily converted to other materials such as gold or silver telluride while

preserving the chiral shape opening the way to the formation of strongly optically active nanostructures made

of various plasmonic or semiconductor materials

We now demonstrate enantioselective synthesis of another class of materials Lanthanide phosphate hydrate

nanocrystals (also of chiral space group) in the presence of tartaric acid The formed nanocrystals exhibit

substantial degree of circularly polarized luminescence and their enantiomeric excess depends non-linearly on

the enantiomeric excess of the tartaric acid ligands We believe that this system may be useful for studying the

mechanism of enantioselection of the formed nanocrystal seeds in the presence of the chiral molecules

14

Optical Microcavity Devices Containing Organic Materials

Yaakov R Tischler Department of Chemistry Bar-Ilan University Ramat-Gan Israel

When two dielectric mirrors are positioned closely together a half wavelength apart or an integer multiple

thereof they form a Fabry-Peacuterot resonator that can trap light of a specific wavelength for many optical cycles

This resonant light trapping phenomenon is at the heart of vertical cavity surface emitting lasers (VCSELs)

optical switches resonant cavity LEDs and numerous other photonic and optoelectronic devices When organic

materials are situated inside such photonic structures and stability issues are properly addressed amazing

results can be achieved such as strong light-matter coupling at room temperature in both the visible and

infrared (IR) spectral ranges low threshold lasing and super-radiant coupling between molecules Using

microcavities properly designed for use with organics here we show strong light-matter coupling in the mid-IR

spectral range and the first demonstration of a monolayer VCSEL where the gain layer consists of a thin film

of fluorescent dye that is one molecule thick We motivate possible sensor applications for these devices and

discuss the unique physical photochemical and photoelectrochemical processes that can be investigated in

such structures

15

Keynote Lecture

Stability Study of Cation Moieties in Alkaline Anion Exchange Membranes for

Fuel Cell Applications

Dario Dekel1 Charles E Diesendruck2 1Chemical Engineering Technion - Israel Institute of Technology Haifa Israel

2Chemistry Technion - Israel Institute of Technology Haifa Israel

There is an increasing worldwide interest in anion exchange membrane fuel cells (AEMFCs) due to the

potential of this technology to use low cost electrocatalysts promising a considerable cost reduction for new

generation of fuel cell devices However the stability of anion conducting polymers for durable anion exchange

membranes (AEMs) and anion exchange ionomers (AEIs) is still a great concern

Here we present a novel methodology to measure the true alkaline stability of anion conducting polymers to be

used in AEMFCs The new ex-situ technique simulates the environment of an AEMFC during operation where

nucleophilic and basic OH- species in the absence or with scarce amount of water attack the functional groups

of the ionic polymer Using this technique we clearly show the critical effect of water molecules on the alkaline

stability of quaternary ammonium (QA) cations commonly used as functional groups in AEMFCs

The results show that as the water content is reduced the QA cations are more rapidly degraded in the presence

of OH- at room temperature With increasing number of water molecules solvating the hydroxide its

nucleophilicity and basicity are hindered and the QA degradation is significantly slowed These results indicate

that the currently used aqueous alkali ex-situ tests to measure AEM stability may lead to false positive stability

results where anion conducting polymers may appear more alkali stable than they really are

We strongly recommend the adoption of this novel developed technique to measure the true stability of anion

conducting polymers to be used for AEMFCs We believe that this new ex-situ protocol will rapidly lead to

development and selection of best stable polymers for durable and robust AEMFCs

16

Probing the Electrode-Electrolyte Interface in Rechargeable Batteries by Solid

State NMR

Michal Leskes Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Reactions at the electrode-electrolyte interface in lithium ion batteries play a key role in the batteryrsquos

performance and are one of the main causes for cell failure These reactions which lead to the formation of the

solid electrolyte interphase (SEI) ultimately control the reversibility of the cellrsquos Li chemistry and its kinetics

Thus an important part in the development of new high energy storage materials is control over their interfacial

chemistry and reactivity with the electrolyte Nuclear magnetic resonance (NMR) spectroscopy is an excellent

approach for following the formation of interfacial layers as it can detect disordered and heterogeneous phases

providing information on their chemical composition structure and dynamic properties Its main disadvantage

is its low sensitivity which is often a limiting factor when probing the SEI Here Irsquoll describe approaches to

overcome this sensitivity limitation by isotope enrichment as well as the potential of new hyperpolarization

techniques which can provide detailed molecular level insight into the chemistry of the SEI

17

First-Principles Based Studies of Complex Oxide Materials

Ilya Grinberg Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Since their first discovery over 70 years ago complex ferroelectric oxides have been shown to exhibit a wide

variety of physical and chemical properties that enable their use in a broad range of applications In particular

the dynamics in a class of complex ferroelectric solid solutions known as relaxors have been under

investigation due to their glass-like behavior and excellent technological properties Nevertheless despite over

50 years of research the key bonding motifs of relaxor ferroelectrics that give rise to their fascinating properties

such as ultrahigh piezoelectric coefficients high permittivity over a broad temperature range diffuse phase

transition without macroscopic lattice symmetry strong frequency dependence in dielectric response and

phonon anomalies are still subject to debate We use molecular dynamics simulations for the prototypical

Pb(Mg13Nb23)O3-PbTiO3 relaxor material to examine the structure bonding and the spatial and temporal

correlations of relaxors Our simulations show that the unusual properties of relaxors simply stem from the

presence of a multidomain state with an extremely small asymp2-10 nm domain size and that dynamics of relaxors

exhibit striking similarities to those of water arising from the local-environment dependent dipole decoupling

due to chemical bonding variation at particular atomic sites

Ferroelectric materials have also recently attracted increased attention as a candidate class of materials for use

in photovoltaic devices In a series of computational studies of a variety of ferroelectric perovskite oxides we

showed that the physical behaviors of these materials are governed by the simple local structure and chemical

bonding characteristics these can then be modified to rationally design new materials with light absorption

through the visible range that enables the use of these materials in photovoltaic applications

18

Colorimetric Detection of the Early Stages of Aluminum Oxidation Using

Plasmonic Gold NanondashIsland Films

Alexander Tesler1 Eyal Sabatani3 Takumi Sannomiya4 Yishai Feldman2

Alexander Vaskevich1 Israel Rubinstein1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemistry Division Nuclear Research Centre Negev Beer-Sheva Israel

4Materials Science amp Engineering Tokyo Institute of Technology Yokohama Kanagawa

Japan

Corrosion is a natural process of degradation of metallic parts reacting with their environment and is the major

cause of failure of metal structures inndashservice Hence detection of the early stages of environmental oxidation

of metal parts is of great importance Here we present a colorimetric method for monitoring the surface

conditions of aluminum using the localized surface plasmon resonance (LSPR) response of gold nanoparticles

(NPs) prendashdeposited onto the aluminum surface Upon oxidation metallic aluminum transforms to transparent

dielectric aluminum oxide (or hydroxide) In water the formed oxidation product adopts a twondashlayer structure

the bottom layer is thinner and compact while the top layer is thicker and highly porous The gold nanondashisland

layer initially deposited (by evaporationannealing) on the aluminum surface maintains its integrity after

corrosion in water and is located between the two aluminum oxide layers Water oxidation of aluminum

substrates with an overlayer of plasmonic gold nano-islands leads to a pronounced color change which can be

monitored in situ using reflection spectroscopy or colorimetrically by the naked eye Theoretical calculations

show that the major spectral change during corrosion is attributed to the interplay between plasmonic scattering

of the Au NP layer reacting to the changing environment and interference within the bottom aluminum oxide

layer acting as an etalon sandwiched between the Au islands and the underlying aluminum The top porous

oxide layer has only a marginal contribution The results indicate that plasmonic gold NPs are well suited for

realndashtime monitoring of the corrosion kinetics of aluminum and its alloys in aqueous environment and in air

The technique is costndasheffective and can be carried out in the transmission or reflection configuration

19

Vertically Aligned Molybdenum Disulfide for Efficient Lithium Storage

Victor Shokhen1 Yana Miroshnikov1 Gregory Gershinsky1 Noam Gotlib2 Chen Stern2

Doron Naveh2 David Zitoun1 1Chemistry Nanotechnology and Advanced Materials (BINA) Bar-Ilan University

Ramat-Gan Israel 2Faculty of Engineering Bar-Ilan University Ramat-Gan Israel

Layered transition-metal disulfides (LTMDs) have played a prominent role in the development of electronic

energy conversion and storage devices Molybdenum disulfide (MoS2) has been widely investigated as a highly

efficient alternative to existing materials Most fabrication pathways of MoS2 focus on its planar growth on

various substrates to reach high-quality layers with planar orientation (PO) Nevertheless in most energy-

storage applications the most relevant orientation is the vertical alignment (VA) of well-defined layers VA

growth paves the way to highly dense devices with exposed active sites on the surface Here the chemical

vapor deposition (CVD) process has been investigated to grow 2H-MoS2 films hundreds of nanometers thick

with VA stacking The films show large domains of perfectly aligned layers with high crystallinity and density

and low surface roughness CVD-grown VA-MoS2 films show superior behavior in lithium storage with stable

capacity even at a high current density compared to PO-MoS2 films The VA-MoS2 films show a high

reversible capacity of 800 mAhg for lithium storage which corresponds to the full conversion to Mo and Li2S

HR-TEM images of VA-MoS2 Capacity of VA-MoS2 compare to PO-MoS2

20

Tailoring the Electronic Structure of TeY-doped NbBiO4 using Oxygen-

vacancy for All-oxide PV Application A Theoretical and Experimental Study

Vijay Singh Susanta Das David Keller Dan Thomas Major

Department of Chemistry Bar-Ilan University Ramat-Gan Israel

First principles studies of point defects and impurities in semiconductors insulators and metals have become an

integral part of material research over the last few decades1 Point defects and impurities often have decisive

effects on material properties2 3 Recently using density functional theory (DFT) calculations we have revealed

that Bi2O3 is a low band-gap material and the obtained energy band-gap 230 eV lies in the region of PV

interest The observed optical transitions between the valence band (VB) (O-2p states) and the conduction band

(CB) (Bi-6p states) are not allowed due to violation of the dipole selection rule (Δl =+-1) Therefore Bi2O3 is

not a potential absorber material for photovoltaic (PV) applications With the aid of DFT calculations and

experimental measurements we have also studied the NbBiO4 system extensively and our results revealed that

its valence band (VB) and conduction band (CB) consist of optically active states but its large energy band gap

350 eV puts a constraint on its use as an absorber material In the present talk I shall discuss how with the

help of suitable doping as well as oxygen vacancy we managed to reduce the energy band gap of NbBiO4 from

350 eV to 220 eV without changing its electronic structure The observed band-gap is in the region of PV

interest and transitions between the CB and VB states are optically allowed Using COHP (energy resolved

visualization of chemical bonding) calculations we revealed that Y doping in NbBiO4 significantly reduces the

covalent bonding between Bi and nearest neighbors oxygen ions from 100 eVbond to 010 eVbond As a

consequence the computed oxygen defect formation energies for Y-doped NbBiO4 system is lower than the

oxygen defect formation energies of the pure NbBiO4 system contributing to a large oxygen-defect

concentration Thus the significance of oxygen vacancy in Y-doped NbBiO4 (YBi site only) was revealed

and this study might serve to design better PV absorber materials in the future

References

1] Freysoldt C Grabowski B Hickel T Neugebauer J Kresse G Janotti A Van de Walle C G First-

principles calculations for point defects in solids Rev Mod Phys 2014 86 253-305

2] Ganguli N Dasgupta I Sanyal B Electronic structure and magnetism of transition metal doped Zn12O12

clusters Role of defects J Appl Phys 2010 108 123911

3] Yavo N Smith A D Yeheskel O Cohen S Korobko R Wachtel E Slater P R Lubomirsky I

Large Nonclassical Electrostriction in (Y Nb)‐ Stabilized δ‐ Bi2O3 Adv Funct Mater 2016

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

12

Pyroelectricity from Non-Polar Crystals Enables Understanding Features of

Crystal Growth and Design

Meir Lahav Elena Meirzadeh Eran Mishuk David Ehre Igor Lubomirsky

Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Pyroelectricity a property of certain crystalline materials is the creation of a temporary surface charge upon

temperature change resulting in an external electric current Thermal movement of the molecules alters their

average positions leading to changes in their dipole moments As a consequence of this property spontaneous

polarization was constricted to the polar directions of the ten polar crystal classes when exposed to temperature

change resulting in the creation of two oppositely charged faces which engender pyroelectricity With the

emergence of modern analytical instruments for measuring electric currents it became possible however to

probe the structures of polar defects and imperfections and near surface polar layers that outline non-polar

crystals In spite of their slight amounts those architectures play indispensible role for the understanding of the

different features that control the macroscopic properties of crystals and provide perceptiveness on the

mechanisms of crystal growth

The following sub-topics will be presented

a) Deciphering the riddle of polarity found in the growth of the centrosymmetric crystals of glycine1-2

b) Enantiomeric disorder within the crystals of DL alanine not detectable by diffraction3

c) Solvent molecules as ldquotailor-maderdquo auxiliary in the control of crystal polymorphism as illustrated with the

three polymorphs of glycine4

d) Pyroelectricity combined with theoretical simulations as a new analytical method for the structure

determination of polar tiny-doped domains in crystals at the molecular level5

(1) Meirzadeh E Sapir L et al JACS 2016 138 14756

(2) Piperno S et al Angew Chem Int Ed 2013 52 6513

(3) Mishuk E et al Cryst Growth Des 2014 14 3839

(4) Meirzadeh E Dishon S work in progress

(5) Meirzadeh E Azuri I et al Nature Com 2016 7 13354

13

Enantioselective Synthesis of Intrinsically Chiral Nanocrystals

Gil Markovich Assaf Ben Moshe Uri Hananel

School of Chemistry Tel Aviv University Tel Aviv Israel

We have recently shown that it is possible to perform an enantioselective synthesis of inorganic nanostructures

made of intrinsically chiral crystals such as a-HgS Te and Se These crystals belonging to the P3121 (or

P3221) chiral space group were grown as nanocrystals in the presence of thiolated chiral molecules such as

cysteine penicillamine or glutathione This led to a preference in the growth of the nanocrystals towards a

certain handedness and consequent strong optical activity

Furthermore in the case of Te nanostructures particular synthesis conditions led to overall chiral shape of the

elongated nanostructures expressed as a twist on the scale of the size of the nanostructures of the order of 100

nm Finally the Te could be easily converted to other materials such as gold or silver telluride while

preserving the chiral shape opening the way to the formation of strongly optically active nanostructures made

of various plasmonic or semiconductor materials

We now demonstrate enantioselective synthesis of another class of materials Lanthanide phosphate hydrate

nanocrystals (also of chiral space group) in the presence of tartaric acid The formed nanocrystals exhibit

substantial degree of circularly polarized luminescence and their enantiomeric excess depends non-linearly on

the enantiomeric excess of the tartaric acid ligands We believe that this system may be useful for studying the

mechanism of enantioselection of the formed nanocrystal seeds in the presence of the chiral molecules

14

Optical Microcavity Devices Containing Organic Materials

Yaakov R Tischler Department of Chemistry Bar-Ilan University Ramat-Gan Israel

When two dielectric mirrors are positioned closely together a half wavelength apart or an integer multiple

thereof they form a Fabry-Peacuterot resonator that can trap light of a specific wavelength for many optical cycles

This resonant light trapping phenomenon is at the heart of vertical cavity surface emitting lasers (VCSELs)

optical switches resonant cavity LEDs and numerous other photonic and optoelectronic devices When organic

materials are situated inside such photonic structures and stability issues are properly addressed amazing

results can be achieved such as strong light-matter coupling at room temperature in both the visible and

infrared (IR) spectral ranges low threshold lasing and super-radiant coupling between molecules Using

microcavities properly designed for use with organics here we show strong light-matter coupling in the mid-IR

spectral range and the first demonstration of a monolayer VCSEL where the gain layer consists of a thin film

of fluorescent dye that is one molecule thick We motivate possible sensor applications for these devices and

discuss the unique physical photochemical and photoelectrochemical processes that can be investigated in

such structures

15

Keynote Lecture

Stability Study of Cation Moieties in Alkaline Anion Exchange Membranes for

Fuel Cell Applications

Dario Dekel1 Charles E Diesendruck2 1Chemical Engineering Technion - Israel Institute of Technology Haifa Israel

2Chemistry Technion - Israel Institute of Technology Haifa Israel

There is an increasing worldwide interest in anion exchange membrane fuel cells (AEMFCs) due to the

potential of this technology to use low cost electrocatalysts promising a considerable cost reduction for new

generation of fuel cell devices However the stability of anion conducting polymers for durable anion exchange

membranes (AEMs) and anion exchange ionomers (AEIs) is still a great concern

Here we present a novel methodology to measure the true alkaline stability of anion conducting polymers to be

used in AEMFCs The new ex-situ technique simulates the environment of an AEMFC during operation where

nucleophilic and basic OH- species in the absence or with scarce amount of water attack the functional groups

of the ionic polymer Using this technique we clearly show the critical effect of water molecules on the alkaline

stability of quaternary ammonium (QA) cations commonly used as functional groups in AEMFCs

The results show that as the water content is reduced the QA cations are more rapidly degraded in the presence

of OH- at room temperature With increasing number of water molecules solvating the hydroxide its

nucleophilicity and basicity are hindered and the QA degradation is significantly slowed These results indicate

that the currently used aqueous alkali ex-situ tests to measure AEM stability may lead to false positive stability

results where anion conducting polymers may appear more alkali stable than they really are

We strongly recommend the adoption of this novel developed technique to measure the true stability of anion

conducting polymers to be used for AEMFCs We believe that this new ex-situ protocol will rapidly lead to

development and selection of best stable polymers for durable and robust AEMFCs

16

Probing the Electrode-Electrolyte Interface in Rechargeable Batteries by Solid

State NMR

Michal Leskes Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Reactions at the electrode-electrolyte interface in lithium ion batteries play a key role in the batteryrsquos

performance and are one of the main causes for cell failure These reactions which lead to the formation of the

solid electrolyte interphase (SEI) ultimately control the reversibility of the cellrsquos Li chemistry and its kinetics

Thus an important part in the development of new high energy storage materials is control over their interfacial

chemistry and reactivity with the electrolyte Nuclear magnetic resonance (NMR) spectroscopy is an excellent

approach for following the formation of interfacial layers as it can detect disordered and heterogeneous phases

providing information on their chemical composition structure and dynamic properties Its main disadvantage

is its low sensitivity which is often a limiting factor when probing the SEI Here Irsquoll describe approaches to

overcome this sensitivity limitation by isotope enrichment as well as the potential of new hyperpolarization

techniques which can provide detailed molecular level insight into the chemistry of the SEI

17

First-Principles Based Studies of Complex Oxide Materials

Ilya Grinberg Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Since their first discovery over 70 years ago complex ferroelectric oxides have been shown to exhibit a wide

variety of physical and chemical properties that enable their use in a broad range of applications In particular

the dynamics in a class of complex ferroelectric solid solutions known as relaxors have been under

investigation due to their glass-like behavior and excellent technological properties Nevertheless despite over

50 years of research the key bonding motifs of relaxor ferroelectrics that give rise to their fascinating properties

such as ultrahigh piezoelectric coefficients high permittivity over a broad temperature range diffuse phase

transition without macroscopic lattice symmetry strong frequency dependence in dielectric response and

phonon anomalies are still subject to debate We use molecular dynamics simulations for the prototypical

Pb(Mg13Nb23)O3-PbTiO3 relaxor material to examine the structure bonding and the spatial and temporal

correlations of relaxors Our simulations show that the unusual properties of relaxors simply stem from the

presence of a multidomain state with an extremely small asymp2-10 nm domain size and that dynamics of relaxors

exhibit striking similarities to those of water arising from the local-environment dependent dipole decoupling

due to chemical bonding variation at particular atomic sites

Ferroelectric materials have also recently attracted increased attention as a candidate class of materials for use

in photovoltaic devices In a series of computational studies of a variety of ferroelectric perovskite oxides we

showed that the physical behaviors of these materials are governed by the simple local structure and chemical

bonding characteristics these can then be modified to rationally design new materials with light absorption

through the visible range that enables the use of these materials in photovoltaic applications

18

Colorimetric Detection of the Early Stages of Aluminum Oxidation Using

Plasmonic Gold NanondashIsland Films

Alexander Tesler1 Eyal Sabatani3 Takumi Sannomiya4 Yishai Feldman2

Alexander Vaskevich1 Israel Rubinstein1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemistry Division Nuclear Research Centre Negev Beer-Sheva Israel

4Materials Science amp Engineering Tokyo Institute of Technology Yokohama Kanagawa

Japan

Corrosion is a natural process of degradation of metallic parts reacting with their environment and is the major

cause of failure of metal structures inndashservice Hence detection of the early stages of environmental oxidation

of metal parts is of great importance Here we present a colorimetric method for monitoring the surface

conditions of aluminum using the localized surface plasmon resonance (LSPR) response of gold nanoparticles

(NPs) prendashdeposited onto the aluminum surface Upon oxidation metallic aluminum transforms to transparent

dielectric aluminum oxide (or hydroxide) In water the formed oxidation product adopts a twondashlayer structure

the bottom layer is thinner and compact while the top layer is thicker and highly porous The gold nanondashisland

layer initially deposited (by evaporationannealing) on the aluminum surface maintains its integrity after

corrosion in water and is located between the two aluminum oxide layers Water oxidation of aluminum

substrates with an overlayer of plasmonic gold nano-islands leads to a pronounced color change which can be

monitored in situ using reflection spectroscopy or colorimetrically by the naked eye Theoretical calculations

show that the major spectral change during corrosion is attributed to the interplay between plasmonic scattering

of the Au NP layer reacting to the changing environment and interference within the bottom aluminum oxide

layer acting as an etalon sandwiched between the Au islands and the underlying aluminum The top porous

oxide layer has only a marginal contribution The results indicate that plasmonic gold NPs are well suited for

realndashtime monitoring of the corrosion kinetics of aluminum and its alloys in aqueous environment and in air

The technique is costndasheffective and can be carried out in the transmission or reflection configuration

19

Vertically Aligned Molybdenum Disulfide for Efficient Lithium Storage

Victor Shokhen1 Yana Miroshnikov1 Gregory Gershinsky1 Noam Gotlib2 Chen Stern2

Doron Naveh2 David Zitoun1 1Chemistry Nanotechnology and Advanced Materials (BINA) Bar-Ilan University

Ramat-Gan Israel 2Faculty of Engineering Bar-Ilan University Ramat-Gan Israel

Layered transition-metal disulfides (LTMDs) have played a prominent role in the development of electronic

energy conversion and storage devices Molybdenum disulfide (MoS2) has been widely investigated as a highly

efficient alternative to existing materials Most fabrication pathways of MoS2 focus on its planar growth on

various substrates to reach high-quality layers with planar orientation (PO) Nevertheless in most energy-

storage applications the most relevant orientation is the vertical alignment (VA) of well-defined layers VA

growth paves the way to highly dense devices with exposed active sites on the surface Here the chemical

vapor deposition (CVD) process has been investigated to grow 2H-MoS2 films hundreds of nanometers thick

with VA stacking The films show large domains of perfectly aligned layers with high crystallinity and density

and low surface roughness CVD-grown VA-MoS2 films show superior behavior in lithium storage with stable

capacity even at a high current density compared to PO-MoS2 films The VA-MoS2 films show a high

reversible capacity of 800 mAhg for lithium storage which corresponds to the full conversion to Mo and Li2S

HR-TEM images of VA-MoS2 Capacity of VA-MoS2 compare to PO-MoS2

20

Tailoring the Electronic Structure of TeY-doped NbBiO4 using Oxygen-

vacancy for All-oxide PV Application A Theoretical and Experimental Study

Vijay Singh Susanta Das David Keller Dan Thomas Major

Department of Chemistry Bar-Ilan University Ramat-Gan Israel

First principles studies of point defects and impurities in semiconductors insulators and metals have become an

integral part of material research over the last few decades1 Point defects and impurities often have decisive

effects on material properties2 3 Recently using density functional theory (DFT) calculations we have revealed

that Bi2O3 is a low band-gap material and the obtained energy band-gap 230 eV lies in the region of PV

interest The observed optical transitions between the valence band (VB) (O-2p states) and the conduction band

(CB) (Bi-6p states) are not allowed due to violation of the dipole selection rule (Δl =+-1) Therefore Bi2O3 is

not a potential absorber material for photovoltaic (PV) applications With the aid of DFT calculations and

experimental measurements we have also studied the NbBiO4 system extensively and our results revealed that

its valence band (VB) and conduction band (CB) consist of optically active states but its large energy band gap

350 eV puts a constraint on its use as an absorber material In the present talk I shall discuss how with the

help of suitable doping as well as oxygen vacancy we managed to reduce the energy band gap of NbBiO4 from

350 eV to 220 eV without changing its electronic structure The observed band-gap is in the region of PV

interest and transitions between the CB and VB states are optically allowed Using COHP (energy resolved

visualization of chemical bonding) calculations we revealed that Y doping in NbBiO4 significantly reduces the

covalent bonding between Bi and nearest neighbors oxygen ions from 100 eVbond to 010 eVbond As a

consequence the computed oxygen defect formation energies for Y-doped NbBiO4 system is lower than the

oxygen defect formation energies of the pure NbBiO4 system contributing to a large oxygen-defect

concentration Thus the significance of oxygen vacancy in Y-doped NbBiO4 (YBi site only) was revealed

and this study might serve to design better PV absorber materials in the future

References

1] Freysoldt C Grabowski B Hickel T Neugebauer J Kresse G Janotti A Van de Walle C G First-

principles calculations for point defects in solids Rev Mod Phys 2014 86 253-305

2] Ganguli N Dasgupta I Sanyal B Electronic structure and magnetism of transition metal doped Zn12O12

clusters Role of defects J Appl Phys 2010 108 123911

3] Yavo N Smith A D Yeheskel O Cohen S Korobko R Wachtel E Slater P R Lubomirsky I

Large Nonclassical Electrostriction in (Y Nb)‐ Stabilized δ‐ Bi2O3 Adv Funct Mater 2016

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

13

Enantioselective Synthesis of Intrinsically Chiral Nanocrystals

Gil Markovich Assaf Ben Moshe Uri Hananel

School of Chemistry Tel Aviv University Tel Aviv Israel

We have recently shown that it is possible to perform an enantioselective synthesis of inorganic nanostructures

made of intrinsically chiral crystals such as a-HgS Te and Se These crystals belonging to the P3121 (or

P3221) chiral space group were grown as nanocrystals in the presence of thiolated chiral molecules such as

cysteine penicillamine or glutathione This led to a preference in the growth of the nanocrystals towards a

certain handedness and consequent strong optical activity

Furthermore in the case of Te nanostructures particular synthesis conditions led to overall chiral shape of the

elongated nanostructures expressed as a twist on the scale of the size of the nanostructures of the order of 100

nm Finally the Te could be easily converted to other materials such as gold or silver telluride while

preserving the chiral shape opening the way to the formation of strongly optically active nanostructures made

of various plasmonic or semiconductor materials

We now demonstrate enantioselective synthesis of another class of materials Lanthanide phosphate hydrate

nanocrystals (also of chiral space group) in the presence of tartaric acid The formed nanocrystals exhibit

substantial degree of circularly polarized luminescence and their enantiomeric excess depends non-linearly on

the enantiomeric excess of the tartaric acid ligands We believe that this system may be useful for studying the

mechanism of enantioselection of the formed nanocrystal seeds in the presence of the chiral molecules

14

Optical Microcavity Devices Containing Organic Materials

Yaakov R Tischler Department of Chemistry Bar-Ilan University Ramat-Gan Israel

When two dielectric mirrors are positioned closely together a half wavelength apart or an integer multiple

thereof they form a Fabry-Peacuterot resonator that can trap light of a specific wavelength for many optical cycles

This resonant light trapping phenomenon is at the heart of vertical cavity surface emitting lasers (VCSELs)

optical switches resonant cavity LEDs and numerous other photonic and optoelectronic devices When organic

materials are situated inside such photonic structures and stability issues are properly addressed amazing

results can be achieved such as strong light-matter coupling at room temperature in both the visible and

infrared (IR) spectral ranges low threshold lasing and super-radiant coupling between molecules Using

microcavities properly designed for use with organics here we show strong light-matter coupling in the mid-IR

spectral range and the first demonstration of a monolayer VCSEL where the gain layer consists of a thin film

of fluorescent dye that is one molecule thick We motivate possible sensor applications for these devices and

discuss the unique physical photochemical and photoelectrochemical processes that can be investigated in

such structures

15

Keynote Lecture

Stability Study of Cation Moieties in Alkaline Anion Exchange Membranes for

Fuel Cell Applications

Dario Dekel1 Charles E Diesendruck2 1Chemical Engineering Technion - Israel Institute of Technology Haifa Israel

2Chemistry Technion - Israel Institute of Technology Haifa Israel

There is an increasing worldwide interest in anion exchange membrane fuel cells (AEMFCs) due to the

potential of this technology to use low cost electrocatalysts promising a considerable cost reduction for new

generation of fuel cell devices However the stability of anion conducting polymers for durable anion exchange

membranes (AEMs) and anion exchange ionomers (AEIs) is still a great concern

Here we present a novel methodology to measure the true alkaline stability of anion conducting polymers to be

used in AEMFCs The new ex-situ technique simulates the environment of an AEMFC during operation where

nucleophilic and basic OH- species in the absence or with scarce amount of water attack the functional groups

of the ionic polymer Using this technique we clearly show the critical effect of water molecules on the alkaline

stability of quaternary ammonium (QA) cations commonly used as functional groups in AEMFCs

The results show that as the water content is reduced the QA cations are more rapidly degraded in the presence

of OH- at room temperature With increasing number of water molecules solvating the hydroxide its

nucleophilicity and basicity are hindered and the QA degradation is significantly slowed These results indicate

that the currently used aqueous alkali ex-situ tests to measure AEM stability may lead to false positive stability

results where anion conducting polymers may appear more alkali stable than they really are

We strongly recommend the adoption of this novel developed technique to measure the true stability of anion

conducting polymers to be used for AEMFCs We believe that this new ex-situ protocol will rapidly lead to

development and selection of best stable polymers for durable and robust AEMFCs

16

Probing the Electrode-Electrolyte Interface in Rechargeable Batteries by Solid

State NMR

Michal Leskes Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Reactions at the electrode-electrolyte interface in lithium ion batteries play a key role in the batteryrsquos

performance and are one of the main causes for cell failure These reactions which lead to the formation of the

solid electrolyte interphase (SEI) ultimately control the reversibility of the cellrsquos Li chemistry and its kinetics

Thus an important part in the development of new high energy storage materials is control over their interfacial

chemistry and reactivity with the electrolyte Nuclear magnetic resonance (NMR) spectroscopy is an excellent

approach for following the formation of interfacial layers as it can detect disordered and heterogeneous phases

providing information on their chemical composition structure and dynamic properties Its main disadvantage

is its low sensitivity which is often a limiting factor when probing the SEI Here Irsquoll describe approaches to

overcome this sensitivity limitation by isotope enrichment as well as the potential of new hyperpolarization

techniques which can provide detailed molecular level insight into the chemistry of the SEI

17

First-Principles Based Studies of Complex Oxide Materials

Ilya Grinberg Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Since their first discovery over 70 years ago complex ferroelectric oxides have been shown to exhibit a wide

variety of physical and chemical properties that enable their use in a broad range of applications In particular

the dynamics in a class of complex ferroelectric solid solutions known as relaxors have been under

investigation due to their glass-like behavior and excellent technological properties Nevertheless despite over

50 years of research the key bonding motifs of relaxor ferroelectrics that give rise to their fascinating properties

such as ultrahigh piezoelectric coefficients high permittivity over a broad temperature range diffuse phase

transition without macroscopic lattice symmetry strong frequency dependence in dielectric response and

phonon anomalies are still subject to debate We use molecular dynamics simulations for the prototypical

Pb(Mg13Nb23)O3-PbTiO3 relaxor material to examine the structure bonding and the spatial and temporal

correlations of relaxors Our simulations show that the unusual properties of relaxors simply stem from the

presence of a multidomain state with an extremely small asymp2-10 nm domain size and that dynamics of relaxors

exhibit striking similarities to those of water arising from the local-environment dependent dipole decoupling

due to chemical bonding variation at particular atomic sites

Ferroelectric materials have also recently attracted increased attention as a candidate class of materials for use

in photovoltaic devices In a series of computational studies of a variety of ferroelectric perovskite oxides we

showed that the physical behaviors of these materials are governed by the simple local structure and chemical

bonding characteristics these can then be modified to rationally design new materials with light absorption

through the visible range that enables the use of these materials in photovoltaic applications

18

Colorimetric Detection of the Early Stages of Aluminum Oxidation Using

Plasmonic Gold NanondashIsland Films

Alexander Tesler1 Eyal Sabatani3 Takumi Sannomiya4 Yishai Feldman2

Alexander Vaskevich1 Israel Rubinstein1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemistry Division Nuclear Research Centre Negev Beer-Sheva Israel

4Materials Science amp Engineering Tokyo Institute of Technology Yokohama Kanagawa

Japan

Corrosion is a natural process of degradation of metallic parts reacting with their environment and is the major

cause of failure of metal structures inndashservice Hence detection of the early stages of environmental oxidation

of metal parts is of great importance Here we present a colorimetric method for monitoring the surface

conditions of aluminum using the localized surface plasmon resonance (LSPR) response of gold nanoparticles

(NPs) prendashdeposited onto the aluminum surface Upon oxidation metallic aluminum transforms to transparent

dielectric aluminum oxide (or hydroxide) In water the formed oxidation product adopts a twondashlayer structure

the bottom layer is thinner and compact while the top layer is thicker and highly porous The gold nanondashisland

layer initially deposited (by evaporationannealing) on the aluminum surface maintains its integrity after

corrosion in water and is located between the two aluminum oxide layers Water oxidation of aluminum

substrates with an overlayer of plasmonic gold nano-islands leads to a pronounced color change which can be

monitored in situ using reflection spectroscopy or colorimetrically by the naked eye Theoretical calculations

show that the major spectral change during corrosion is attributed to the interplay between plasmonic scattering

of the Au NP layer reacting to the changing environment and interference within the bottom aluminum oxide

layer acting as an etalon sandwiched between the Au islands and the underlying aluminum The top porous

oxide layer has only a marginal contribution The results indicate that plasmonic gold NPs are well suited for

realndashtime monitoring of the corrosion kinetics of aluminum and its alloys in aqueous environment and in air

The technique is costndasheffective and can be carried out in the transmission or reflection configuration

19

Vertically Aligned Molybdenum Disulfide for Efficient Lithium Storage

Victor Shokhen1 Yana Miroshnikov1 Gregory Gershinsky1 Noam Gotlib2 Chen Stern2

Doron Naveh2 David Zitoun1 1Chemistry Nanotechnology and Advanced Materials (BINA) Bar-Ilan University

Ramat-Gan Israel 2Faculty of Engineering Bar-Ilan University Ramat-Gan Israel

Layered transition-metal disulfides (LTMDs) have played a prominent role in the development of electronic

energy conversion and storage devices Molybdenum disulfide (MoS2) has been widely investigated as a highly

efficient alternative to existing materials Most fabrication pathways of MoS2 focus on its planar growth on

various substrates to reach high-quality layers with planar orientation (PO) Nevertheless in most energy-

storage applications the most relevant orientation is the vertical alignment (VA) of well-defined layers VA

growth paves the way to highly dense devices with exposed active sites on the surface Here the chemical

vapor deposition (CVD) process has been investigated to grow 2H-MoS2 films hundreds of nanometers thick

with VA stacking The films show large domains of perfectly aligned layers with high crystallinity and density

and low surface roughness CVD-grown VA-MoS2 films show superior behavior in lithium storage with stable

capacity even at a high current density compared to PO-MoS2 films The VA-MoS2 films show a high

reversible capacity of 800 mAhg for lithium storage which corresponds to the full conversion to Mo and Li2S

HR-TEM images of VA-MoS2 Capacity of VA-MoS2 compare to PO-MoS2

20

Tailoring the Electronic Structure of TeY-doped NbBiO4 using Oxygen-

vacancy for All-oxide PV Application A Theoretical and Experimental Study

Vijay Singh Susanta Das David Keller Dan Thomas Major

Department of Chemistry Bar-Ilan University Ramat-Gan Israel

First principles studies of point defects and impurities in semiconductors insulators and metals have become an

integral part of material research over the last few decades1 Point defects and impurities often have decisive

effects on material properties2 3 Recently using density functional theory (DFT) calculations we have revealed

that Bi2O3 is a low band-gap material and the obtained energy band-gap 230 eV lies in the region of PV

interest The observed optical transitions between the valence band (VB) (O-2p states) and the conduction band

(CB) (Bi-6p states) are not allowed due to violation of the dipole selection rule (Δl =+-1) Therefore Bi2O3 is

not a potential absorber material for photovoltaic (PV) applications With the aid of DFT calculations and

experimental measurements we have also studied the NbBiO4 system extensively and our results revealed that

its valence band (VB) and conduction band (CB) consist of optically active states but its large energy band gap

350 eV puts a constraint on its use as an absorber material In the present talk I shall discuss how with the

help of suitable doping as well as oxygen vacancy we managed to reduce the energy band gap of NbBiO4 from

350 eV to 220 eV without changing its electronic structure The observed band-gap is in the region of PV

interest and transitions between the CB and VB states are optically allowed Using COHP (energy resolved

visualization of chemical bonding) calculations we revealed that Y doping in NbBiO4 significantly reduces the

covalent bonding between Bi and nearest neighbors oxygen ions from 100 eVbond to 010 eVbond As a

consequence the computed oxygen defect formation energies for Y-doped NbBiO4 system is lower than the

oxygen defect formation energies of the pure NbBiO4 system contributing to a large oxygen-defect

concentration Thus the significance of oxygen vacancy in Y-doped NbBiO4 (YBi site only) was revealed

and this study might serve to design better PV absorber materials in the future

References

1] Freysoldt C Grabowski B Hickel T Neugebauer J Kresse G Janotti A Van de Walle C G First-

principles calculations for point defects in solids Rev Mod Phys 2014 86 253-305

2] Ganguli N Dasgupta I Sanyal B Electronic structure and magnetism of transition metal doped Zn12O12

clusters Role of defects J Appl Phys 2010 108 123911

3] Yavo N Smith A D Yeheskel O Cohen S Korobko R Wachtel E Slater P R Lubomirsky I

Large Nonclassical Electrostriction in (Y Nb)‐ Stabilized δ‐ Bi2O3 Adv Funct Mater 2016

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

14

Optical Microcavity Devices Containing Organic Materials

Yaakov R Tischler Department of Chemistry Bar-Ilan University Ramat-Gan Israel

When two dielectric mirrors are positioned closely together a half wavelength apart or an integer multiple

thereof they form a Fabry-Peacuterot resonator that can trap light of a specific wavelength for many optical cycles

This resonant light trapping phenomenon is at the heart of vertical cavity surface emitting lasers (VCSELs)

optical switches resonant cavity LEDs and numerous other photonic and optoelectronic devices When organic

materials are situated inside such photonic structures and stability issues are properly addressed amazing

results can be achieved such as strong light-matter coupling at room temperature in both the visible and

infrared (IR) spectral ranges low threshold lasing and super-radiant coupling between molecules Using

microcavities properly designed for use with organics here we show strong light-matter coupling in the mid-IR

spectral range and the first demonstration of a monolayer VCSEL where the gain layer consists of a thin film

of fluorescent dye that is one molecule thick We motivate possible sensor applications for these devices and

discuss the unique physical photochemical and photoelectrochemical processes that can be investigated in

such structures

15

Keynote Lecture

Stability Study of Cation Moieties in Alkaline Anion Exchange Membranes for

Fuel Cell Applications

Dario Dekel1 Charles E Diesendruck2 1Chemical Engineering Technion - Israel Institute of Technology Haifa Israel

2Chemistry Technion - Israel Institute of Technology Haifa Israel

There is an increasing worldwide interest in anion exchange membrane fuel cells (AEMFCs) due to the

potential of this technology to use low cost electrocatalysts promising a considerable cost reduction for new

generation of fuel cell devices However the stability of anion conducting polymers for durable anion exchange

membranes (AEMs) and anion exchange ionomers (AEIs) is still a great concern

Here we present a novel methodology to measure the true alkaline stability of anion conducting polymers to be

used in AEMFCs The new ex-situ technique simulates the environment of an AEMFC during operation where

nucleophilic and basic OH- species in the absence or with scarce amount of water attack the functional groups

of the ionic polymer Using this technique we clearly show the critical effect of water molecules on the alkaline

stability of quaternary ammonium (QA) cations commonly used as functional groups in AEMFCs

The results show that as the water content is reduced the QA cations are more rapidly degraded in the presence

of OH- at room temperature With increasing number of water molecules solvating the hydroxide its

nucleophilicity and basicity are hindered and the QA degradation is significantly slowed These results indicate

that the currently used aqueous alkali ex-situ tests to measure AEM stability may lead to false positive stability

results where anion conducting polymers may appear more alkali stable than they really are

We strongly recommend the adoption of this novel developed technique to measure the true stability of anion

conducting polymers to be used for AEMFCs We believe that this new ex-situ protocol will rapidly lead to

development and selection of best stable polymers for durable and robust AEMFCs

16

Probing the Electrode-Electrolyte Interface in Rechargeable Batteries by Solid

State NMR

Michal Leskes Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Reactions at the electrode-electrolyte interface in lithium ion batteries play a key role in the batteryrsquos

performance and are one of the main causes for cell failure These reactions which lead to the formation of the

solid electrolyte interphase (SEI) ultimately control the reversibility of the cellrsquos Li chemistry and its kinetics

Thus an important part in the development of new high energy storage materials is control over their interfacial

chemistry and reactivity with the electrolyte Nuclear magnetic resonance (NMR) spectroscopy is an excellent

approach for following the formation of interfacial layers as it can detect disordered and heterogeneous phases

providing information on their chemical composition structure and dynamic properties Its main disadvantage

is its low sensitivity which is often a limiting factor when probing the SEI Here Irsquoll describe approaches to

overcome this sensitivity limitation by isotope enrichment as well as the potential of new hyperpolarization

techniques which can provide detailed molecular level insight into the chemistry of the SEI

17

First-Principles Based Studies of Complex Oxide Materials

Ilya Grinberg Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Since their first discovery over 70 years ago complex ferroelectric oxides have been shown to exhibit a wide

variety of physical and chemical properties that enable their use in a broad range of applications In particular

the dynamics in a class of complex ferroelectric solid solutions known as relaxors have been under

investigation due to their glass-like behavior and excellent technological properties Nevertheless despite over

50 years of research the key bonding motifs of relaxor ferroelectrics that give rise to their fascinating properties

such as ultrahigh piezoelectric coefficients high permittivity over a broad temperature range diffuse phase

transition without macroscopic lattice symmetry strong frequency dependence in dielectric response and

phonon anomalies are still subject to debate We use molecular dynamics simulations for the prototypical

Pb(Mg13Nb23)O3-PbTiO3 relaxor material to examine the structure bonding and the spatial and temporal

correlations of relaxors Our simulations show that the unusual properties of relaxors simply stem from the

presence of a multidomain state with an extremely small asymp2-10 nm domain size and that dynamics of relaxors

exhibit striking similarities to those of water arising from the local-environment dependent dipole decoupling

due to chemical bonding variation at particular atomic sites

Ferroelectric materials have also recently attracted increased attention as a candidate class of materials for use

in photovoltaic devices In a series of computational studies of a variety of ferroelectric perovskite oxides we

showed that the physical behaviors of these materials are governed by the simple local structure and chemical

bonding characteristics these can then be modified to rationally design new materials with light absorption

through the visible range that enables the use of these materials in photovoltaic applications

18

Colorimetric Detection of the Early Stages of Aluminum Oxidation Using

Plasmonic Gold NanondashIsland Films

Alexander Tesler1 Eyal Sabatani3 Takumi Sannomiya4 Yishai Feldman2

Alexander Vaskevich1 Israel Rubinstein1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemistry Division Nuclear Research Centre Negev Beer-Sheva Israel

4Materials Science amp Engineering Tokyo Institute of Technology Yokohama Kanagawa

Japan

Corrosion is a natural process of degradation of metallic parts reacting with their environment and is the major

cause of failure of metal structures inndashservice Hence detection of the early stages of environmental oxidation

of metal parts is of great importance Here we present a colorimetric method for monitoring the surface

conditions of aluminum using the localized surface plasmon resonance (LSPR) response of gold nanoparticles

(NPs) prendashdeposited onto the aluminum surface Upon oxidation metallic aluminum transforms to transparent

dielectric aluminum oxide (or hydroxide) In water the formed oxidation product adopts a twondashlayer structure

the bottom layer is thinner and compact while the top layer is thicker and highly porous The gold nanondashisland

layer initially deposited (by evaporationannealing) on the aluminum surface maintains its integrity after

corrosion in water and is located between the two aluminum oxide layers Water oxidation of aluminum

substrates with an overlayer of plasmonic gold nano-islands leads to a pronounced color change which can be

monitored in situ using reflection spectroscopy or colorimetrically by the naked eye Theoretical calculations

show that the major spectral change during corrosion is attributed to the interplay between plasmonic scattering

of the Au NP layer reacting to the changing environment and interference within the bottom aluminum oxide

layer acting as an etalon sandwiched between the Au islands and the underlying aluminum The top porous

oxide layer has only a marginal contribution The results indicate that plasmonic gold NPs are well suited for

realndashtime monitoring of the corrosion kinetics of aluminum and its alloys in aqueous environment and in air

The technique is costndasheffective and can be carried out in the transmission or reflection configuration

19

Vertically Aligned Molybdenum Disulfide for Efficient Lithium Storage

Victor Shokhen1 Yana Miroshnikov1 Gregory Gershinsky1 Noam Gotlib2 Chen Stern2

Doron Naveh2 David Zitoun1 1Chemistry Nanotechnology and Advanced Materials (BINA) Bar-Ilan University

Ramat-Gan Israel 2Faculty of Engineering Bar-Ilan University Ramat-Gan Israel

Layered transition-metal disulfides (LTMDs) have played a prominent role in the development of electronic

energy conversion and storage devices Molybdenum disulfide (MoS2) has been widely investigated as a highly

efficient alternative to existing materials Most fabrication pathways of MoS2 focus on its planar growth on

various substrates to reach high-quality layers with planar orientation (PO) Nevertheless in most energy-

storage applications the most relevant orientation is the vertical alignment (VA) of well-defined layers VA

growth paves the way to highly dense devices with exposed active sites on the surface Here the chemical

vapor deposition (CVD) process has been investigated to grow 2H-MoS2 films hundreds of nanometers thick

with VA stacking The films show large domains of perfectly aligned layers with high crystallinity and density

and low surface roughness CVD-grown VA-MoS2 films show superior behavior in lithium storage with stable

capacity even at a high current density compared to PO-MoS2 films The VA-MoS2 films show a high

reversible capacity of 800 mAhg for lithium storage which corresponds to the full conversion to Mo and Li2S

HR-TEM images of VA-MoS2 Capacity of VA-MoS2 compare to PO-MoS2

20

Tailoring the Electronic Structure of TeY-doped NbBiO4 using Oxygen-

vacancy for All-oxide PV Application A Theoretical and Experimental Study

Vijay Singh Susanta Das David Keller Dan Thomas Major

Department of Chemistry Bar-Ilan University Ramat-Gan Israel

First principles studies of point defects and impurities in semiconductors insulators and metals have become an

integral part of material research over the last few decades1 Point defects and impurities often have decisive

effects on material properties2 3 Recently using density functional theory (DFT) calculations we have revealed

that Bi2O3 is a low band-gap material and the obtained energy band-gap 230 eV lies in the region of PV

interest The observed optical transitions between the valence band (VB) (O-2p states) and the conduction band

(CB) (Bi-6p states) are not allowed due to violation of the dipole selection rule (Δl =+-1) Therefore Bi2O3 is

not a potential absorber material for photovoltaic (PV) applications With the aid of DFT calculations and

experimental measurements we have also studied the NbBiO4 system extensively and our results revealed that

its valence band (VB) and conduction band (CB) consist of optically active states but its large energy band gap

350 eV puts a constraint on its use as an absorber material In the present talk I shall discuss how with the

help of suitable doping as well as oxygen vacancy we managed to reduce the energy band gap of NbBiO4 from

350 eV to 220 eV without changing its electronic structure The observed band-gap is in the region of PV

interest and transitions between the CB and VB states are optically allowed Using COHP (energy resolved

visualization of chemical bonding) calculations we revealed that Y doping in NbBiO4 significantly reduces the

covalent bonding between Bi and nearest neighbors oxygen ions from 100 eVbond to 010 eVbond As a

consequence the computed oxygen defect formation energies for Y-doped NbBiO4 system is lower than the

oxygen defect formation energies of the pure NbBiO4 system contributing to a large oxygen-defect

concentration Thus the significance of oxygen vacancy in Y-doped NbBiO4 (YBi site only) was revealed

and this study might serve to design better PV absorber materials in the future

References

1] Freysoldt C Grabowski B Hickel T Neugebauer J Kresse G Janotti A Van de Walle C G First-

principles calculations for point defects in solids Rev Mod Phys 2014 86 253-305

2] Ganguli N Dasgupta I Sanyal B Electronic structure and magnetism of transition metal doped Zn12O12

clusters Role of defects J Appl Phys 2010 108 123911

3] Yavo N Smith A D Yeheskel O Cohen S Korobko R Wachtel E Slater P R Lubomirsky I

Large Nonclassical Electrostriction in (Y Nb)‐ Stabilized δ‐ Bi2O3 Adv Funct Mater 2016

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

15

Keynote Lecture

Stability Study of Cation Moieties in Alkaline Anion Exchange Membranes for

Fuel Cell Applications

Dario Dekel1 Charles E Diesendruck2 1Chemical Engineering Technion - Israel Institute of Technology Haifa Israel

2Chemistry Technion - Israel Institute of Technology Haifa Israel

There is an increasing worldwide interest in anion exchange membrane fuel cells (AEMFCs) due to the

potential of this technology to use low cost electrocatalysts promising a considerable cost reduction for new

generation of fuel cell devices However the stability of anion conducting polymers for durable anion exchange

membranes (AEMs) and anion exchange ionomers (AEIs) is still a great concern

Here we present a novel methodology to measure the true alkaline stability of anion conducting polymers to be

used in AEMFCs The new ex-situ technique simulates the environment of an AEMFC during operation where

nucleophilic and basic OH- species in the absence or with scarce amount of water attack the functional groups

of the ionic polymer Using this technique we clearly show the critical effect of water molecules on the alkaline

stability of quaternary ammonium (QA) cations commonly used as functional groups in AEMFCs

The results show that as the water content is reduced the QA cations are more rapidly degraded in the presence

of OH- at room temperature With increasing number of water molecules solvating the hydroxide its

nucleophilicity and basicity are hindered and the QA degradation is significantly slowed These results indicate

that the currently used aqueous alkali ex-situ tests to measure AEM stability may lead to false positive stability

results where anion conducting polymers may appear more alkali stable than they really are

We strongly recommend the adoption of this novel developed technique to measure the true stability of anion

conducting polymers to be used for AEMFCs We believe that this new ex-situ protocol will rapidly lead to

development and selection of best stable polymers for durable and robust AEMFCs

16

Probing the Electrode-Electrolyte Interface in Rechargeable Batteries by Solid

State NMR

Michal Leskes Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Reactions at the electrode-electrolyte interface in lithium ion batteries play a key role in the batteryrsquos

performance and are one of the main causes for cell failure These reactions which lead to the formation of the

solid electrolyte interphase (SEI) ultimately control the reversibility of the cellrsquos Li chemistry and its kinetics

Thus an important part in the development of new high energy storage materials is control over their interfacial

chemistry and reactivity with the electrolyte Nuclear magnetic resonance (NMR) spectroscopy is an excellent

approach for following the formation of interfacial layers as it can detect disordered and heterogeneous phases

providing information on their chemical composition structure and dynamic properties Its main disadvantage

is its low sensitivity which is often a limiting factor when probing the SEI Here Irsquoll describe approaches to

overcome this sensitivity limitation by isotope enrichment as well as the potential of new hyperpolarization

techniques which can provide detailed molecular level insight into the chemistry of the SEI

17

First-Principles Based Studies of Complex Oxide Materials

Ilya Grinberg Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Since their first discovery over 70 years ago complex ferroelectric oxides have been shown to exhibit a wide

variety of physical and chemical properties that enable their use in a broad range of applications In particular

the dynamics in a class of complex ferroelectric solid solutions known as relaxors have been under

investigation due to their glass-like behavior and excellent technological properties Nevertheless despite over

50 years of research the key bonding motifs of relaxor ferroelectrics that give rise to their fascinating properties

such as ultrahigh piezoelectric coefficients high permittivity over a broad temperature range diffuse phase

transition without macroscopic lattice symmetry strong frequency dependence in dielectric response and

phonon anomalies are still subject to debate We use molecular dynamics simulations for the prototypical

Pb(Mg13Nb23)O3-PbTiO3 relaxor material to examine the structure bonding and the spatial and temporal

correlations of relaxors Our simulations show that the unusual properties of relaxors simply stem from the

presence of a multidomain state with an extremely small asymp2-10 nm domain size and that dynamics of relaxors

exhibit striking similarities to those of water arising from the local-environment dependent dipole decoupling

due to chemical bonding variation at particular atomic sites

Ferroelectric materials have also recently attracted increased attention as a candidate class of materials for use

in photovoltaic devices In a series of computational studies of a variety of ferroelectric perovskite oxides we

showed that the physical behaviors of these materials are governed by the simple local structure and chemical

bonding characteristics these can then be modified to rationally design new materials with light absorption

through the visible range that enables the use of these materials in photovoltaic applications

18

Colorimetric Detection of the Early Stages of Aluminum Oxidation Using

Plasmonic Gold NanondashIsland Films

Alexander Tesler1 Eyal Sabatani3 Takumi Sannomiya4 Yishai Feldman2

Alexander Vaskevich1 Israel Rubinstein1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemistry Division Nuclear Research Centre Negev Beer-Sheva Israel

4Materials Science amp Engineering Tokyo Institute of Technology Yokohama Kanagawa

Japan

Corrosion is a natural process of degradation of metallic parts reacting with their environment and is the major

cause of failure of metal structures inndashservice Hence detection of the early stages of environmental oxidation

of metal parts is of great importance Here we present a colorimetric method for monitoring the surface

conditions of aluminum using the localized surface plasmon resonance (LSPR) response of gold nanoparticles

(NPs) prendashdeposited onto the aluminum surface Upon oxidation metallic aluminum transforms to transparent

dielectric aluminum oxide (or hydroxide) In water the formed oxidation product adopts a twondashlayer structure

the bottom layer is thinner and compact while the top layer is thicker and highly porous The gold nanondashisland

layer initially deposited (by evaporationannealing) on the aluminum surface maintains its integrity after

corrosion in water and is located between the two aluminum oxide layers Water oxidation of aluminum

substrates with an overlayer of plasmonic gold nano-islands leads to a pronounced color change which can be

monitored in situ using reflection spectroscopy or colorimetrically by the naked eye Theoretical calculations

show that the major spectral change during corrosion is attributed to the interplay between plasmonic scattering

of the Au NP layer reacting to the changing environment and interference within the bottom aluminum oxide

layer acting as an etalon sandwiched between the Au islands and the underlying aluminum The top porous

oxide layer has only a marginal contribution The results indicate that plasmonic gold NPs are well suited for

realndashtime monitoring of the corrosion kinetics of aluminum and its alloys in aqueous environment and in air

The technique is costndasheffective and can be carried out in the transmission or reflection configuration

19

Vertically Aligned Molybdenum Disulfide for Efficient Lithium Storage

Victor Shokhen1 Yana Miroshnikov1 Gregory Gershinsky1 Noam Gotlib2 Chen Stern2

Doron Naveh2 David Zitoun1 1Chemistry Nanotechnology and Advanced Materials (BINA) Bar-Ilan University

Ramat-Gan Israel 2Faculty of Engineering Bar-Ilan University Ramat-Gan Israel

Layered transition-metal disulfides (LTMDs) have played a prominent role in the development of electronic

energy conversion and storage devices Molybdenum disulfide (MoS2) has been widely investigated as a highly

efficient alternative to existing materials Most fabrication pathways of MoS2 focus on its planar growth on

various substrates to reach high-quality layers with planar orientation (PO) Nevertheless in most energy-

storage applications the most relevant orientation is the vertical alignment (VA) of well-defined layers VA

growth paves the way to highly dense devices with exposed active sites on the surface Here the chemical

vapor deposition (CVD) process has been investigated to grow 2H-MoS2 films hundreds of nanometers thick

with VA stacking The films show large domains of perfectly aligned layers with high crystallinity and density

and low surface roughness CVD-grown VA-MoS2 films show superior behavior in lithium storage with stable

capacity even at a high current density compared to PO-MoS2 films The VA-MoS2 films show a high

reversible capacity of 800 mAhg for lithium storage which corresponds to the full conversion to Mo and Li2S

HR-TEM images of VA-MoS2 Capacity of VA-MoS2 compare to PO-MoS2

20

Tailoring the Electronic Structure of TeY-doped NbBiO4 using Oxygen-

vacancy for All-oxide PV Application A Theoretical and Experimental Study

Vijay Singh Susanta Das David Keller Dan Thomas Major

Department of Chemistry Bar-Ilan University Ramat-Gan Israel

First principles studies of point defects and impurities in semiconductors insulators and metals have become an

integral part of material research over the last few decades1 Point defects and impurities often have decisive

effects on material properties2 3 Recently using density functional theory (DFT) calculations we have revealed

that Bi2O3 is a low band-gap material and the obtained energy band-gap 230 eV lies in the region of PV

interest The observed optical transitions between the valence band (VB) (O-2p states) and the conduction band

(CB) (Bi-6p states) are not allowed due to violation of the dipole selection rule (Δl =+-1) Therefore Bi2O3 is

not a potential absorber material for photovoltaic (PV) applications With the aid of DFT calculations and

experimental measurements we have also studied the NbBiO4 system extensively and our results revealed that

its valence band (VB) and conduction band (CB) consist of optically active states but its large energy band gap

350 eV puts a constraint on its use as an absorber material In the present talk I shall discuss how with the

help of suitable doping as well as oxygen vacancy we managed to reduce the energy band gap of NbBiO4 from

350 eV to 220 eV without changing its electronic structure The observed band-gap is in the region of PV

interest and transitions between the CB and VB states are optically allowed Using COHP (energy resolved

visualization of chemical bonding) calculations we revealed that Y doping in NbBiO4 significantly reduces the

covalent bonding between Bi and nearest neighbors oxygen ions from 100 eVbond to 010 eVbond As a

consequence the computed oxygen defect formation energies for Y-doped NbBiO4 system is lower than the

oxygen defect formation energies of the pure NbBiO4 system contributing to a large oxygen-defect

concentration Thus the significance of oxygen vacancy in Y-doped NbBiO4 (YBi site only) was revealed

and this study might serve to design better PV absorber materials in the future

References

1] Freysoldt C Grabowski B Hickel T Neugebauer J Kresse G Janotti A Van de Walle C G First-

principles calculations for point defects in solids Rev Mod Phys 2014 86 253-305

2] Ganguli N Dasgupta I Sanyal B Electronic structure and magnetism of transition metal doped Zn12O12

clusters Role of defects J Appl Phys 2010 108 123911

3] Yavo N Smith A D Yeheskel O Cohen S Korobko R Wachtel E Slater P R Lubomirsky I

Large Nonclassical Electrostriction in (Y Nb)‐ Stabilized δ‐ Bi2O3 Adv Funct Mater 2016

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

16

Probing the Electrode-Electrolyte Interface in Rechargeable Batteries by Solid

State NMR

Michal Leskes Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Reactions at the electrode-electrolyte interface in lithium ion batteries play a key role in the batteryrsquos

performance and are one of the main causes for cell failure These reactions which lead to the formation of the

solid electrolyte interphase (SEI) ultimately control the reversibility of the cellrsquos Li chemistry and its kinetics

Thus an important part in the development of new high energy storage materials is control over their interfacial

chemistry and reactivity with the electrolyte Nuclear magnetic resonance (NMR) spectroscopy is an excellent

approach for following the formation of interfacial layers as it can detect disordered and heterogeneous phases

providing information on their chemical composition structure and dynamic properties Its main disadvantage

is its low sensitivity which is often a limiting factor when probing the SEI Here Irsquoll describe approaches to

overcome this sensitivity limitation by isotope enrichment as well as the potential of new hyperpolarization

techniques which can provide detailed molecular level insight into the chemistry of the SEI

17

First-Principles Based Studies of Complex Oxide Materials

Ilya Grinberg Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Since their first discovery over 70 years ago complex ferroelectric oxides have been shown to exhibit a wide

variety of physical and chemical properties that enable their use in a broad range of applications In particular

the dynamics in a class of complex ferroelectric solid solutions known as relaxors have been under

investigation due to their glass-like behavior and excellent technological properties Nevertheless despite over

50 years of research the key bonding motifs of relaxor ferroelectrics that give rise to their fascinating properties

such as ultrahigh piezoelectric coefficients high permittivity over a broad temperature range diffuse phase

transition without macroscopic lattice symmetry strong frequency dependence in dielectric response and

phonon anomalies are still subject to debate We use molecular dynamics simulations for the prototypical

Pb(Mg13Nb23)O3-PbTiO3 relaxor material to examine the structure bonding and the spatial and temporal

correlations of relaxors Our simulations show that the unusual properties of relaxors simply stem from the

presence of a multidomain state with an extremely small asymp2-10 nm domain size and that dynamics of relaxors

exhibit striking similarities to those of water arising from the local-environment dependent dipole decoupling

due to chemical bonding variation at particular atomic sites

Ferroelectric materials have also recently attracted increased attention as a candidate class of materials for use

in photovoltaic devices In a series of computational studies of a variety of ferroelectric perovskite oxides we

showed that the physical behaviors of these materials are governed by the simple local structure and chemical

bonding characteristics these can then be modified to rationally design new materials with light absorption

through the visible range that enables the use of these materials in photovoltaic applications

18

Colorimetric Detection of the Early Stages of Aluminum Oxidation Using

Plasmonic Gold NanondashIsland Films

Alexander Tesler1 Eyal Sabatani3 Takumi Sannomiya4 Yishai Feldman2

Alexander Vaskevich1 Israel Rubinstein1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemistry Division Nuclear Research Centre Negev Beer-Sheva Israel

4Materials Science amp Engineering Tokyo Institute of Technology Yokohama Kanagawa

Japan

Corrosion is a natural process of degradation of metallic parts reacting with their environment and is the major

cause of failure of metal structures inndashservice Hence detection of the early stages of environmental oxidation

of metal parts is of great importance Here we present a colorimetric method for monitoring the surface

conditions of aluminum using the localized surface plasmon resonance (LSPR) response of gold nanoparticles

(NPs) prendashdeposited onto the aluminum surface Upon oxidation metallic aluminum transforms to transparent

dielectric aluminum oxide (or hydroxide) In water the formed oxidation product adopts a twondashlayer structure

the bottom layer is thinner and compact while the top layer is thicker and highly porous The gold nanondashisland

layer initially deposited (by evaporationannealing) on the aluminum surface maintains its integrity after

corrosion in water and is located between the two aluminum oxide layers Water oxidation of aluminum

substrates with an overlayer of plasmonic gold nano-islands leads to a pronounced color change which can be

monitored in situ using reflection spectroscopy or colorimetrically by the naked eye Theoretical calculations

show that the major spectral change during corrosion is attributed to the interplay between plasmonic scattering

of the Au NP layer reacting to the changing environment and interference within the bottom aluminum oxide

layer acting as an etalon sandwiched between the Au islands and the underlying aluminum The top porous

oxide layer has only a marginal contribution The results indicate that plasmonic gold NPs are well suited for

realndashtime monitoring of the corrosion kinetics of aluminum and its alloys in aqueous environment and in air

The technique is costndasheffective and can be carried out in the transmission or reflection configuration

19

Vertically Aligned Molybdenum Disulfide for Efficient Lithium Storage

Victor Shokhen1 Yana Miroshnikov1 Gregory Gershinsky1 Noam Gotlib2 Chen Stern2

Doron Naveh2 David Zitoun1 1Chemistry Nanotechnology and Advanced Materials (BINA) Bar-Ilan University

Ramat-Gan Israel 2Faculty of Engineering Bar-Ilan University Ramat-Gan Israel

Layered transition-metal disulfides (LTMDs) have played a prominent role in the development of electronic

energy conversion and storage devices Molybdenum disulfide (MoS2) has been widely investigated as a highly

efficient alternative to existing materials Most fabrication pathways of MoS2 focus on its planar growth on

various substrates to reach high-quality layers with planar orientation (PO) Nevertheless in most energy-

storage applications the most relevant orientation is the vertical alignment (VA) of well-defined layers VA

growth paves the way to highly dense devices with exposed active sites on the surface Here the chemical

vapor deposition (CVD) process has been investigated to grow 2H-MoS2 films hundreds of nanometers thick

with VA stacking The films show large domains of perfectly aligned layers with high crystallinity and density

and low surface roughness CVD-grown VA-MoS2 films show superior behavior in lithium storage with stable

capacity even at a high current density compared to PO-MoS2 films The VA-MoS2 films show a high

reversible capacity of 800 mAhg for lithium storage which corresponds to the full conversion to Mo and Li2S

HR-TEM images of VA-MoS2 Capacity of VA-MoS2 compare to PO-MoS2

20

Tailoring the Electronic Structure of TeY-doped NbBiO4 using Oxygen-

vacancy for All-oxide PV Application A Theoretical and Experimental Study

Vijay Singh Susanta Das David Keller Dan Thomas Major

Department of Chemistry Bar-Ilan University Ramat-Gan Israel

First principles studies of point defects and impurities in semiconductors insulators and metals have become an

integral part of material research over the last few decades1 Point defects and impurities often have decisive

effects on material properties2 3 Recently using density functional theory (DFT) calculations we have revealed

that Bi2O3 is a low band-gap material and the obtained energy band-gap 230 eV lies in the region of PV

interest The observed optical transitions between the valence band (VB) (O-2p states) and the conduction band

(CB) (Bi-6p states) are not allowed due to violation of the dipole selection rule (Δl =+-1) Therefore Bi2O3 is

not a potential absorber material for photovoltaic (PV) applications With the aid of DFT calculations and

experimental measurements we have also studied the NbBiO4 system extensively and our results revealed that

its valence band (VB) and conduction band (CB) consist of optically active states but its large energy band gap

350 eV puts a constraint on its use as an absorber material In the present talk I shall discuss how with the

help of suitable doping as well as oxygen vacancy we managed to reduce the energy band gap of NbBiO4 from

350 eV to 220 eV without changing its electronic structure The observed band-gap is in the region of PV

interest and transitions between the CB and VB states are optically allowed Using COHP (energy resolved

visualization of chemical bonding) calculations we revealed that Y doping in NbBiO4 significantly reduces the

covalent bonding between Bi and nearest neighbors oxygen ions from 100 eVbond to 010 eVbond As a

consequence the computed oxygen defect formation energies for Y-doped NbBiO4 system is lower than the

oxygen defect formation energies of the pure NbBiO4 system contributing to a large oxygen-defect

concentration Thus the significance of oxygen vacancy in Y-doped NbBiO4 (YBi site only) was revealed

and this study might serve to design better PV absorber materials in the future

References

1] Freysoldt C Grabowski B Hickel T Neugebauer J Kresse G Janotti A Van de Walle C G First-

principles calculations for point defects in solids Rev Mod Phys 2014 86 253-305

2] Ganguli N Dasgupta I Sanyal B Electronic structure and magnetism of transition metal doped Zn12O12

clusters Role of defects J Appl Phys 2010 108 123911

3] Yavo N Smith A D Yeheskel O Cohen S Korobko R Wachtel E Slater P R Lubomirsky I

Large Nonclassical Electrostriction in (Y Nb)‐ Stabilized δ‐ Bi2O3 Adv Funct Mater 2016

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

17

First-Principles Based Studies of Complex Oxide Materials

Ilya Grinberg Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Since their first discovery over 70 years ago complex ferroelectric oxides have been shown to exhibit a wide

variety of physical and chemical properties that enable their use in a broad range of applications In particular

the dynamics in a class of complex ferroelectric solid solutions known as relaxors have been under

investigation due to their glass-like behavior and excellent technological properties Nevertheless despite over

50 years of research the key bonding motifs of relaxor ferroelectrics that give rise to their fascinating properties

such as ultrahigh piezoelectric coefficients high permittivity over a broad temperature range diffuse phase

transition without macroscopic lattice symmetry strong frequency dependence in dielectric response and

phonon anomalies are still subject to debate We use molecular dynamics simulations for the prototypical

Pb(Mg13Nb23)O3-PbTiO3 relaxor material to examine the structure bonding and the spatial and temporal

correlations of relaxors Our simulations show that the unusual properties of relaxors simply stem from the

presence of a multidomain state with an extremely small asymp2-10 nm domain size and that dynamics of relaxors

exhibit striking similarities to those of water arising from the local-environment dependent dipole decoupling

due to chemical bonding variation at particular atomic sites

Ferroelectric materials have also recently attracted increased attention as a candidate class of materials for use

in photovoltaic devices In a series of computational studies of a variety of ferroelectric perovskite oxides we

showed that the physical behaviors of these materials are governed by the simple local structure and chemical

bonding characteristics these can then be modified to rationally design new materials with light absorption

through the visible range that enables the use of these materials in photovoltaic applications

18

Colorimetric Detection of the Early Stages of Aluminum Oxidation Using

Plasmonic Gold NanondashIsland Films

Alexander Tesler1 Eyal Sabatani3 Takumi Sannomiya4 Yishai Feldman2

Alexander Vaskevich1 Israel Rubinstein1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemistry Division Nuclear Research Centre Negev Beer-Sheva Israel

4Materials Science amp Engineering Tokyo Institute of Technology Yokohama Kanagawa

Japan

Corrosion is a natural process of degradation of metallic parts reacting with their environment and is the major

cause of failure of metal structures inndashservice Hence detection of the early stages of environmental oxidation

of metal parts is of great importance Here we present a colorimetric method for monitoring the surface

conditions of aluminum using the localized surface plasmon resonance (LSPR) response of gold nanoparticles

(NPs) prendashdeposited onto the aluminum surface Upon oxidation metallic aluminum transforms to transparent

dielectric aluminum oxide (or hydroxide) In water the formed oxidation product adopts a twondashlayer structure

the bottom layer is thinner and compact while the top layer is thicker and highly porous The gold nanondashisland

layer initially deposited (by evaporationannealing) on the aluminum surface maintains its integrity after

corrosion in water and is located between the two aluminum oxide layers Water oxidation of aluminum

substrates with an overlayer of plasmonic gold nano-islands leads to a pronounced color change which can be

monitored in situ using reflection spectroscopy or colorimetrically by the naked eye Theoretical calculations

show that the major spectral change during corrosion is attributed to the interplay between plasmonic scattering

of the Au NP layer reacting to the changing environment and interference within the bottom aluminum oxide

layer acting as an etalon sandwiched between the Au islands and the underlying aluminum The top porous

oxide layer has only a marginal contribution The results indicate that plasmonic gold NPs are well suited for

realndashtime monitoring of the corrosion kinetics of aluminum and its alloys in aqueous environment and in air

The technique is costndasheffective and can be carried out in the transmission or reflection configuration

19

Vertically Aligned Molybdenum Disulfide for Efficient Lithium Storage

Victor Shokhen1 Yana Miroshnikov1 Gregory Gershinsky1 Noam Gotlib2 Chen Stern2

Doron Naveh2 David Zitoun1 1Chemistry Nanotechnology and Advanced Materials (BINA) Bar-Ilan University

Ramat-Gan Israel 2Faculty of Engineering Bar-Ilan University Ramat-Gan Israel

Layered transition-metal disulfides (LTMDs) have played a prominent role in the development of electronic

energy conversion and storage devices Molybdenum disulfide (MoS2) has been widely investigated as a highly

efficient alternative to existing materials Most fabrication pathways of MoS2 focus on its planar growth on

various substrates to reach high-quality layers with planar orientation (PO) Nevertheless in most energy-

storage applications the most relevant orientation is the vertical alignment (VA) of well-defined layers VA

growth paves the way to highly dense devices with exposed active sites on the surface Here the chemical

vapor deposition (CVD) process has been investigated to grow 2H-MoS2 films hundreds of nanometers thick

with VA stacking The films show large domains of perfectly aligned layers with high crystallinity and density

and low surface roughness CVD-grown VA-MoS2 films show superior behavior in lithium storage with stable

capacity even at a high current density compared to PO-MoS2 films The VA-MoS2 films show a high

reversible capacity of 800 mAhg for lithium storage which corresponds to the full conversion to Mo and Li2S

HR-TEM images of VA-MoS2 Capacity of VA-MoS2 compare to PO-MoS2

20

Tailoring the Electronic Structure of TeY-doped NbBiO4 using Oxygen-

vacancy for All-oxide PV Application A Theoretical and Experimental Study

Vijay Singh Susanta Das David Keller Dan Thomas Major

Department of Chemistry Bar-Ilan University Ramat-Gan Israel

First principles studies of point defects and impurities in semiconductors insulators and metals have become an

integral part of material research over the last few decades1 Point defects and impurities often have decisive

effects on material properties2 3 Recently using density functional theory (DFT) calculations we have revealed

that Bi2O3 is a low band-gap material and the obtained energy band-gap 230 eV lies in the region of PV

interest The observed optical transitions between the valence band (VB) (O-2p states) and the conduction band

(CB) (Bi-6p states) are not allowed due to violation of the dipole selection rule (Δl =+-1) Therefore Bi2O3 is

not a potential absorber material for photovoltaic (PV) applications With the aid of DFT calculations and

experimental measurements we have also studied the NbBiO4 system extensively and our results revealed that

its valence band (VB) and conduction band (CB) consist of optically active states but its large energy band gap

350 eV puts a constraint on its use as an absorber material In the present talk I shall discuss how with the

help of suitable doping as well as oxygen vacancy we managed to reduce the energy band gap of NbBiO4 from

350 eV to 220 eV without changing its electronic structure The observed band-gap is in the region of PV

interest and transitions between the CB and VB states are optically allowed Using COHP (energy resolved

visualization of chemical bonding) calculations we revealed that Y doping in NbBiO4 significantly reduces the

covalent bonding between Bi and nearest neighbors oxygen ions from 100 eVbond to 010 eVbond As a

consequence the computed oxygen defect formation energies for Y-doped NbBiO4 system is lower than the

oxygen defect formation energies of the pure NbBiO4 system contributing to a large oxygen-defect

concentration Thus the significance of oxygen vacancy in Y-doped NbBiO4 (YBi site only) was revealed

and this study might serve to design better PV absorber materials in the future

References

1] Freysoldt C Grabowski B Hickel T Neugebauer J Kresse G Janotti A Van de Walle C G First-

principles calculations for point defects in solids Rev Mod Phys 2014 86 253-305

2] Ganguli N Dasgupta I Sanyal B Electronic structure and magnetism of transition metal doped Zn12O12

clusters Role of defects J Appl Phys 2010 108 123911

3] Yavo N Smith A D Yeheskel O Cohen S Korobko R Wachtel E Slater P R Lubomirsky I

Large Nonclassical Electrostriction in (Y Nb)‐ Stabilized δ‐ Bi2O3 Adv Funct Mater 2016

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

18

Colorimetric Detection of the Early Stages of Aluminum Oxidation Using

Plasmonic Gold NanondashIsland Films

Alexander Tesler1 Eyal Sabatani3 Takumi Sannomiya4 Yishai Feldman2

Alexander Vaskevich1 Israel Rubinstein1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Chemical Research Support Weizmann Institute of Science Rehovot Israel 3Chemistry Division Nuclear Research Centre Negev Beer-Sheva Israel

4Materials Science amp Engineering Tokyo Institute of Technology Yokohama Kanagawa

Japan

Corrosion is a natural process of degradation of metallic parts reacting with their environment and is the major

cause of failure of metal structures inndashservice Hence detection of the early stages of environmental oxidation

of metal parts is of great importance Here we present a colorimetric method for monitoring the surface

conditions of aluminum using the localized surface plasmon resonance (LSPR) response of gold nanoparticles

(NPs) prendashdeposited onto the aluminum surface Upon oxidation metallic aluminum transforms to transparent

dielectric aluminum oxide (or hydroxide) In water the formed oxidation product adopts a twondashlayer structure

the bottom layer is thinner and compact while the top layer is thicker and highly porous The gold nanondashisland

layer initially deposited (by evaporationannealing) on the aluminum surface maintains its integrity after

corrosion in water and is located between the two aluminum oxide layers Water oxidation of aluminum

substrates with an overlayer of plasmonic gold nano-islands leads to a pronounced color change which can be

monitored in situ using reflection spectroscopy or colorimetrically by the naked eye Theoretical calculations

show that the major spectral change during corrosion is attributed to the interplay between plasmonic scattering

of the Au NP layer reacting to the changing environment and interference within the bottom aluminum oxide

layer acting as an etalon sandwiched between the Au islands and the underlying aluminum The top porous

oxide layer has only a marginal contribution The results indicate that plasmonic gold NPs are well suited for

realndashtime monitoring of the corrosion kinetics of aluminum and its alloys in aqueous environment and in air

The technique is costndasheffective and can be carried out in the transmission or reflection configuration

19

Vertically Aligned Molybdenum Disulfide for Efficient Lithium Storage

Victor Shokhen1 Yana Miroshnikov1 Gregory Gershinsky1 Noam Gotlib2 Chen Stern2

Doron Naveh2 David Zitoun1 1Chemistry Nanotechnology and Advanced Materials (BINA) Bar-Ilan University

Ramat-Gan Israel 2Faculty of Engineering Bar-Ilan University Ramat-Gan Israel

Layered transition-metal disulfides (LTMDs) have played a prominent role in the development of electronic

energy conversion and storage devices Molybdenum disulfide (MoS2) has been widely investigated as a highly

efficient alternative to existing materials Most fabrication pathways of MoS2 focus on its planar growth on

various substrates to reach high-quality layers with planar orientation (PO) Nevertheless in most energy-

storage applications the most relevant orientation is the vertical alignment (VA) of well-defined layers VA

growth paves the way to highly dense devices with exposed active sites on the surface Here the chemical

vapor deposition (CVD) process has been investigated to grow 2H-MoS2 films hundreds of nanometers thick

with VA stacking The films show large domains of perfectly aligned layers with high crystallinity and density

and low surface roughness CVD-grown VA-MoS2 films show superior behavior in lithium storage with stable

capacity even at a high current density compared to PO-MoS2 films The VA-MoS2 films show a high

reversible capacity of 800 mAhg for lithium storage which corresponds to the full conversion to Mo and Li2S

HR-TEM images of VA-MoS2 Capacity of VA-MoS2 compare to PO-MoS2

20

Tailoring the Electronic Structure of TeY-doped NbBiO4 using Oxygen-

vacancy for All-oxide PV Application A Theoretical and Experimental Study

Vijay Singh Susanta Das David Keller Dan Thomas Major

Department of Chemistry Bar-Ilan University Ramat-Gan Israel

First principles studies of point defects and impurities in semiconductors insulators and metals have become an

integral part of material research over the last few decades1 Point defects and impurities often have decisive

effects on material properties2 3 Recently using density functional theory (DFT) calculations we have revealed

that Bi2O3 is a low band-gap material and the obtained energy band-gap 230 eV lies in the region of PV

interest The observed optical transitions between the valence band (VB) (O-2p states) and the conduction band

(CB) (Bi-6p states) are not allowed due to violation of the dipole selection rule (Δl =+-1) Therefore Bi2O3 is

not a potential absorber material for photovoltaic (PV) applications With the aid of DFT calculations and

experimental measurements we have also studied the NbBiO4 system extensively and our results revealed that

its valence band (VB) and conduction band (CB) consist of optically active states but its large energy band gap

350 eV puts a constraint on its use as an absorber material In the present talk I shall discuss how with the

help of suitable doping as well as oxygen vacancy we managed to reduce the energy band gap of NbBiO4 from

350 eV to 220 eV without changing its electronic structure The observed band-gap is in the region of PV

interest and transitions between the CB and VB states are optically allowed Using COHP (energy resolved

visualization of chemical bonding) calculations we revealed that Y doping in NbBiO4 significantly reduces the

covalent bonding between Bi and nearest neighbors oxygen ions from 100 eVbond to 010 eVbond As a

consequence the computed oxygen defect formation energies for Y-doped NbBiO4 system is lower than the

oxygen defect formation energies of the pure NbBiO4 system contributing to a large oxygen-defect

concentration Thus the significance of oxygen vacancy in Y-doped NbBiO4 (YBi site only) was revealed

and this study might serve to design better PV absorber materials in the future

References

1] Freysoldt C Grabowski B Hickel T Neugebauer J Kresse G Janotti A Van de Walle C G First-

principles calculations for point defects in solids Rev Mod Phys 2014 86 253-305

2] Ganguli N Dasgupta I Sanyal B Electronic structure and magnetism of transition metal doped Zn12O12

clusters Role of defects J Appl Phys 2010 108 123911

3] Yavo N Smith A D Yeheskel O Cohen S Korobko R Wachtel E Slater P R Lubomirsky I

Large Nonclassical Electrostriction in (Y Nb)‐ Stabilized δ‐ Bi2O3 Adv Funct Mater 2016

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

19

Vertically Aligned Molybdenum Disulfide for Efficient Lithium Storage

Victor Shokhen1 Yana Miroshnikov1 Gregory Gershinsky1 Noam Gotlib2 Chen Stern2

Doron Naveh2 David Zitoun1 1Chemistry Nanotechnology and Advanced Materials (BINA) Bar-Ilan University

Ramat-Gan Israel 2Faculty of Engineering Bar-Ilan University Ramat-Gan Israel

Layered transition-metal disulfides (LTMDs) have played a prominent role in the development of electronic

energy conversion and storage devices Molybdenum disulfide (MoS2) has been widely investigated as a highly

efficient alternative to existing materials Most fabrication pathways of MoS2 focus on its planar growth on

various substrates to reach high-quality layers with planar orientation (PO) Nevertheless in most energy-

storage applications the most relevant orientation is the vertical alignment (VA) of well-defined layers VA

growth paves the way to highly dense devices with exposed active sites on the surface Here the chemical

vapor deposition (CVD) process has been investigated to grow 2H-MoS2 films hundreds of nanometers thick

with VA stacking The films show large domains of perfectly aligned layers with high crystallinity and density

and low surface roughness CVD-grown VA-MoS2 films show superior behavior in lithium storage with stable

capacity even at a high current density compared to PO-MoS2 films The VA-MoS2 films show a high

reversible capacity of 800 mAhg for lithium storage which corresponds to the full conversion to Mo and Li2S

HR-TEM images of VA-MoS2 Capacity of VA-MoS2 compare to PO-MoS2

20

Tailoring the Electronic Structure of TeY-doped NbBiO4 using Oxygen-

vacancy for All-oxide PV Application A Theoretical and Experimental Study

Vijay Singh Susanta Das David Keller Dan Thomas Major

Department of Chemistry Bar-Ilan University Ramat-Gan Israel

First principles studies of point defects and impurities in semiconductors insulators and metals have become an

integral part of material research over the last few decades1 Point defects and impurities often have decisive

effects on material properties2 3 Recently using density functional theory (DFT) calculations we have revealed

that Bi2O3 is a low band-gap material and the obtained energy band-gap 230 eV lies in the region of PV

interest The observed optical transitions between the valence band (VB) (O-2p states) and the conduction band

(CB) (Bi-6p states) are not allowed due to violation of the dipole selection rule (Δl =+-1) Therefore Bi2O3 is

not a potential absorber material for photovoltaic (PV) applications With the aid of DFT calculations and

experimental measurements we have also studied the NbBiO4 system extensively and our results revealed that

its valence band (VB) and conduction band (CB) consist of optically active states but its large energy band gap

350 eV puts a constraint on its use as an absorber material In the present talk I shall discuss how with the

help of suitable doping as well as oxygen vacancy we managed to reduce the energy band gap of NbBiO4 from

350 eV to 220 eV without changing its electronic structure The observed band-gap is in the region of PV

interest and transitions between the CB and VB states are optically allowed Using COHP (energy resolved

visualization of chemical bonding) calculations we revealed that Y doping in NbBiO4 significantly reduces the

covalent bonding between Bi and nearest neighbors oxygen ions from 100 eVbond to 010 eVbond As a

consequence the computed oxygen defect formation energies for Y-doped NbBiO4 system is lower than the

oxygen defect formation energies of the pure NbBiO4 system contributing to a large oxygen-defect

concentration Thus the significance of oxygen vacancy in Y-doped NbBiO4 (YBi site only) was revealed

and this study might serve to design better PV absorber materials in the future

References

1] Freysoldt C Grabowski B Hickel T Neugebauer J Kresse G Janotti A Van de Walle C G First-

principles calculations for point defects in solids Rev Mod Phys 2014 86 253-305

2] Ganguli N Dasgupta I Sanyal B Electronic structure and magnetism of transition metal doped Zn12O12

clusters Role of defects J Appl Phys 2010 108 123911

3] Yavo N Smith A D Yeheskel O Cohen S Korobko R Wachtel E Slater P R Lubomirsky I

Large Nonclassical Electrostriction in (Y Nb)‐ Stabilized δ‐ Bi2O3 Adv Funct Mater 2016

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

20

Tailoring the Electronic Structure of TeY-doped NbBiO4 using Oxygen-

vacancy for All-oxide PV Application A Theoretical and Experimental Study

Vijay Singh Susanta Das David Keller Dan Thomas Major

Department of Chemistry Bar-Ilan University Ramat-Gan Israel

First principles studies of point defects and impurities in semiconductors insulators and metals have become an

integral part of material research over the last few decades1 Point defects and impurities often have decisive

effects on material properties2 3 Recently using density functional theory (DFT) calculations we have revealed

that Bi2O3 is a low band-gap material and the obtained energy band-gap 230 eV lies in the region of PV

interest The observed optical transitions between the valence band (VB) (O-2p states) and the conduction band

(CB) (Bi-6p states) are not allowed due to violation of the dipole selection rule (Δl =+-1) Therefore Bi2O3 is

not a potential absorber material for photovoltaic (PV) applications With the aid of DFT calculations and

experimental measurements we have also studied the NbBiO4 system extensively and our results revealed that

its valence band (VB) and conduction band (CB) consist of optically active states but its large energy band gap

350 eV puts a constraint on its use as an absorber material In the present talk I shall discuss how with the

help of suitable doping as well as oxygen vacancy we managed to reduce the energy band gap of NbBiO4 from

350 eV to 220 eV without changing its electronic structure The observed band-gap is in the region of PV

interest and transitions between the CB and VB states are optically allowed Using COHP (energy resolved

visualization of chemical bonding) calculations we revealed that Y doping in NbBiO4 significantly reduces the

covalent bonding between Bi and nearest neighbors oxygen ions from 100 eVbond to 010 eVbond As a

consequence the computed oxygen defect formation energies for Y-doped NbBiO4 system is lower than the

oxygen defect formation energies of the pure NbBiO4 system contributing to a large oxygen-defect

concentration Thus the significance of oxygen vacancy in Y-doped NbBiO4 (YBi site only) was revealed

and this study might serve to design better PV absorber materials in the future

References

1] Freysoldt C Grabowski B Hickel T Neugebauer J Kresse G Janotti A Van de Walle C G First-

principles calculations for point defects in solids Rev Mod Phys 2014 86 253-305

2] Ganguli N Dasgupta I Sanyal B Electronic structure and magnetism of transition metal doped Zn12O12

clusters Role of defects J Appl Phys 2010 108 123911

3] Yavo N Smith A D Yeheskel O Cohen S Korobko R Wachtel E Slater P R Lubomirsky I

Large Nonclassical Electrostriction in (Y Nb)‐ Stabilized δ‐ Bi2O3 Adv Funct Mater 2016

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

21

Keynote Lecture

Orchestrating the Interplay between Lectins and Carbohydrates

Thisbe K Lindhorst Otto Diels Institute of Organic Chemistry Cristiana Albertina University of Kiel Kiel

Germany

All cells are covered with a molecular layer of glycoconjugates with particular complexity dimension and

biological significance This extracellular compartment is called a cellrsquos glycocalyx Molecular recognition of

glycocalyx constituents and their interaction with specialized proteins the lectins are fundamental to cell

biology Hence the molecular regime of glycoconjugates characterizes an individual organism both in health

and disease states

In order to gain a detailed understanding of how carbohydrate-lectin interactions are orchestrated within the

supramolecular environment of the glycocalyx my group has utilized synthetic derivatives of natural

glycoconjugates as well as so-called glycoarrays1 This has allowed us to mimic specific characteristics of the

glycocalyx and to address particular questions and hypotheses about the principles underlying carbohydrate

recognition As a relevant biological system for the investigation of cell-cell interactions we are exploring

carbohydrate-specific adhesion of bacterial cells to surfaces2 In bacterial adhesion we have tested

carbohydrate specificity3 multivalency effects4 and more recently orientational and steric control of cell

adhesion5 involving photoswitchable molecular tools6 The talk will detail our recent approaches in

orchestration and organization of carbohydrates recognition

References

1] A lsquodual clickrsquo strategy for the fabrication of bioselective glycosylated self-assembled monolayers as

glycocalyx models C Grabosch M Kind Y Gies F Schweighoumlfer A Terfort Th K Lindhorst Org

Biomol Chem 2013 11 4006-4015

2] The Bacterial Lectin FimH a Target for Drug Discovery ― Carbohydrate Inhibitors of Type 1

Fimbriae-Mediated Bacterial Adhesion Review M Hartmann Th K Lindhorst Eur J Org Chem

2011 3583-3609

3] Ligands for FimH Th K Lindhorst in Synthesis and Biological Applications of Glycoconjugates

O Renaudet N Spinelli (Eds) Bentham eBooks 2011 pp 12-35

4] Multivalent glycoconjugates as anti-pathogenic agents A Bernardi et al Chem Soc Rev 2013 42

4709-4727

5] Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the

carbohydrate ligand T Weber V Chandrasekaran I Stamer M B Thygesen A Terfort Th K

Lindhorst Angew Chem Int Ed 2014 53 14583-14586

6] Switching first contact photocontrol of E coli adhesion to human cells L Moumlckl A Muumlller C

Braumluchle Th K Lindhorst Chem Commun 2016 52 1254-1257

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

22

Novel Chemical Biological Methods for Detection of Enzyme Activity in

Inflammation

Frank Dekker Maria Eleni Ourailidou Nikolaos Eleftheriadis

Chemical and Pharmaceutical Biology University of Groningen Groningen Netherlands

Bioorthogonal coupling of small organic molecules to protein-bound functional groups is a long-standing

challenge with many implications for cell biology To further address this challenge we developed the oxidative

Heck reaction as a novel strategy for bioorthogonal coupling of arylboronic acids to protein-bound alkenes1

Further development of this reaction led to the identification of EDTA-Pd(II) as a novel catalyst for the

oxidative Heck reaction on protein-bound alkenes which can be employed in fully aqueous reaction

conditions2 This reaction was employed to monitor histone lysine acylation in vitro after metabolic

incorporation of olefinic carboxylates as chemical reporters2 Another successful application was found by

application of the oxidative Heck reaction in a two-step activity-based protein profiling (ABPP) approach for

lipoxygenase activity in biological samples which is a class of enzymes that has not been addressed by ABPP

so far3 Altogether these studies demonstrate that chemistry-based methods enable the investigation of enzyme

activity in the context of inflammation

[1] Ourailidou ME Dockerty P Witte M Poelarends GJ Dekker FJ Metabolic alkene labeling and in vitro

detection of histone acylation via the aqueous oxidative Heck reaction Org Biomol Chem 2015 13(12)

3648-3653

[2] Ourailidou ME van der Meer JY Baas BJ Jeronimus-Stratingh M Gottumukkala AL Poelarends GJ

Minnaard AJ Dekker FJ Aqueous oxidative Heck reaction as a protein-labeling strategy Chembiochem 2014

15(2) 209-212

[3] Eleftheriadis N Thee SA Zwinderman MR Leus NG Dekker FJ Activity-Based Probes for 15-

Lipoxygenase-1 Angew Chem Int Ed Engl 2016 55(40) 12300-12305

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

23

Genetic Encoding of Site-Specific Chemical Modifications in Proteins

Expressed in Bacteria and Cultured Mammalian Cells

Eyal Arbely Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Genetic code expansion (GCE) requires the use of an orthogonal aminoacyl-tRNA synthetasetRNA pair and an

alternative codon (eg the UAG stop codon) to genetically encode the incorporation of non-canonical amino

acids (NCAAs) This technology allows the site-specific incorporation of NCAAs with unique chemical groups

into ribosomally synthesized proteins and thus the study of biologically relevant questions that cannot be

addressed by other methodologies One of the emerging applications of GCE is the incorporation of NCAAs

bearing functional groups at a single site in the protein for subsequent chemoselective reactions We used an

orthogonal and evolved pyrrolysine tRNA synthetasetRNACUA pair to genetically encode the incorporation of

strained alkenes and alkynes into proteins expressed in cultured mammalian cells These proteins were then

labeled with tetrazine-conjugated fluorescent organic dyes via an inverse electron demand Diels-Alder reaction

The site-specific and biorthogonal fluoregenic reaction enabled fluorescent imaging of α-tubulin and membrane

anchored proteins at high resolution in live cells and provided a superior alternative for fluorescence imaging

based on fluorescent proteins Another attractive application of GCE is the incorporation of post-translationally

modified amino acids that allows the synthesis of homogenously and site-specifically modified proteins in

bacteria and cultured mammalian cells In particular we genetically encoded the incorporation of Nε-acetyl

lysine in order to study the structural and functional role of lysine acetylation in the regulation of transcription

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

24

Chemical Biology Directed to Anti-infective Drug Discovery

Mark Broenstrup1 Hans Prochnow1 Haiyu Hu12 Kevin Ferreira1 Verena Fetz1

Peter Paul Muumlller1 1Chemical Biology Helmholtz Centre for Infection Research Braunschweig Germany

2Institute of Materia Medica Chinese Academy of Medical Sciences Beijing China

Our efforts to generate novel antibacterial and antiviral lead substances through chemical biology methods will

be highlighted through two projects

Infections caused by pathogenic bacteria represent a major health threat that is expected to rise further in the

future The need for novel antibiotics is currently not met by RampD efforts in particular in the area of infections

caused by Gram-negative bacteria A main scientific hurdle is the lack of understanding how to assure a

sufficient translocation of bioactive molecules across the Gram-negative cell wall In the talk our efforts to

induce an active transport of small molecules into Gram negative bacteria and methods to quantify such uptake

will be presented

We report the design synthesis and characterization of a series of theranostics agents based on 14710-

tetraazacyclododecane-14710-tetraacetic acid amide (DOTAM) derivatives comprising siderophores that

actively target bacteria inhibit bacterial growth and demonstrate efficacy to visualize bacterial infections in

mice by optical imaging in vivo In addition three orthogonal approaches to detect and quantify the intracellular

accumulation of such conjugates will be presented

In the second part of the talk a structurally intriguing natural product with broad-spectrum action against

multiple human pathogenic viruses will be presented Labyrinthopeptins are post-translationally modified

peptides with lanthionine and labionine bridges that confer a largely enhanced stability in plasma compared to

unmodified peptides Following a first report on the broad anti-HIV and anti-HSV activities of LabyA1 (Feacuterir et

al 2013) we have extended our studies to a variety of enveloped but evolutionary unrelated viruses such as

Herpesviridae (HSV CMV KSHV) Retroviridae (HIV RSV) or the Dengue virus (DENV) Mechanistic

studies through various chemical biology techniques demonstrated that Labyrinthopeptins interact with

lipidomponents of the viral surface thereby inhibiting virus entry into target cells

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

25

The Views Program at the Technion Relieving Israel`s Shortage of Chemistry

Teachers

Yehudit Judy Dori12 Gabby Shwartz1 Orit Herscovitz1 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2STEM Education Samuel Neaman Institute Haifa Israel

Over the last decade Israel has witnessed a declining trend in choosing chemistry as a major and a career along

with a parallel shortage of certified chemistry teachers Choosing a teaching career is associated with onersquos

sense of identity as a teacher Over the past two decades Technion has been preparing the largest number of

chemistry teachers in the country During the last three years this number has increased even more thanks to

the Views program which enables Technion graduates to return to the Technion to study toward an additional

degree at the Faculty of Education in Science and Technology and be certified to become a science technology

engineering or mathematics teacher The Views program which provides students with free tuition via the

President scholarship differs from traditional teacher training programs in studentsrsquo demographics and their

personal characteristics We investigate the process of integrating about 60 novice chemistry teachers who are

Views graduates into the national school system Applying a mixed method approach the study includes

qualitative and quantitative data collection and analysis Preliminary results showed that Views graduates are

highly motivated to become excellent teachers and prefer to integrate disciplinary teaching with leadership

roles Our study aims at contributing to the understanding of chemistry teachers` professional growth in Israel

and reducing the attrition of the novice teachers Its theoretical contribution is the characterization of the

differences in the professional identity between graduates of the Views program and the traditional program

From a practical standpoint the study contributes to establishing guidelines for improving teacher preparation

programs that are envisioned to enhance integration and retention of novice chemistry teachers within the

school system

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

26

Studentsrsquo Understanding of Analogy after a CORE (Chemical Observations

Representations Experimentation) Learning Cycle General Chemistry

Experiment

Shirly Avargil1 Mitchell R M Bruce2 Francois G Amar2 Alice E Bruce2 1School of Education Bar-Ilan University Ramat-Gan Israel

2Department of Chemistry University of Maine Orono Maine USA

Studentsrsquo understanding about analogy was investigated after a CORE (Chemical Observations

Representations Experimentation) learning cycle general chemistry experiment CORE is a three-phase

learning cycle that involves (phase 1) guiding students through chemical observations while they consider a

series of open-ended questions (phase 2) developing representations using analogical thinking and (phase 3)

designing and conducting experiments in response to a scientific question In the CORE experiment used in this

study Polymers and Cross Linking an analogy was employed in phase 2 when students reflected on the

similarities and limitations between objects used in the analogy (the analog) and the chemistry under

observation (the target) Owing to the reliance on analogical reasoning in the CORE approach we conducted a

study at a single point in time at the very beginning of a lab course to investigate studentsrsquo understanding about

analogy the importance of considering the limitations of an analogy and perceived benefits Four online

questions were asked approximately one week after lab work Student responses (n = 501) across the four

questions provided a rich data set of over 60 000 words Results indicate that 75 of students have a basic or

better understanding of the analogy 61 of students connected the analogy with either chemical observations

from lab andor submicroscopic thinking while 8 connected the analogy to both A majority of students

(57) described the importance of appreciating the limitations of an analogical model and numerous students

offered details about how analogy influenced their conceptual understanding The data provide insight into

student understanding about analogy and the degree to which students recognize the limitations of an analogy

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

27

Student Inquiry in Action - from the Original Idea to the Bench

Noa Seri Noa Ofrath Silvana Wesler Eshel Ophir

The Belmonte Science Laboratories Center The Hebrew University of Jerusalem Jerusalem

Israel

Inquiry is the dynamic process of being open to wonder and puzzlement and coming to know and understand

the world As such it is a stance that pervades all aspects of life and is essential to the way in which knowledge

is created

For several years now the Belmonte Science Laboratory Center of the Hebrew University has been holding an

inquiry learning program that combines work with middle school teachers and their students The main

objective of our inquiry program is to stimulate students to independently raise research questions without

limiting them to a particular subject or discipline

The process begins with teachers working with their students to choose a suitable subject This subject derives

from a question problem or exploration that has meaning to the students The teachers then present the selected

topics to the University staff and together they process the idea into a feasible experimental plan Finally the

students come to our laboratories which offer advanced equipment where they carry out a series of

experiments according to their previous plan The process ends with the presentation of the experiment results

in the form of a scientific poster

Some examples of actual Inquiry questions posed by students have been

How does hair coloring influence the strength of the hair

What is the effect of green tea on kidney stones

What is the effect of acidic foods on the decomposition of gluten

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

28

What`s Up Teacher Learning Chemistry in Social Networks

Shelley Rap Science Teaching Weizmann Institute of Science Rehovot Israel

Social networks sites (SNS) which are increasingly being used in recent years allow users to form social

connections and are platforms for advanced technological applications SNS allow active learning interaction

shared learning and sharing of knowledge

Chemistry is one of the most difficult subjects for learning Chemistry learning usually includes theoretical

abstract concepts that form the basis for understanding the science of chemistry that is represented by chemical

symbols The linking between the different levels of understanding makes learning of chemistry difficult for

understanding Without using advanced visualization tools it may cause it to be perceived by students as

abstract and disconnected from the real world The SNSs can be used as a fertile ground for the advancement of

chemistry learning because they are part of the students` everyday life They also make visualization tools such

as advanced simulations and graphics that are available on the platform much more accessible In addition

SNS invites interaction between the teacher and students and between students themselves outside the formal

school hours It also encourages cooperative learning and skills that complement traditional learning

In my talk I will present the learning potential that exists in the Facebook Platform I will describe the

interactions that occur in chemistry learning Facebook groups and the patterns of learning discourse taking

place in them that were found in the research In addition I will present the students` perspective on integration

of Facebook into chemistry studying and their needs in complementary teaching in this regard I will also show

examples how chemistry teachers use specific technology to advance their teaching of selected chemistry

subjects in which students face difficulties

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

29

Laureate of the ICS Tenne Family Prize

Plenary Lecture

Taming Nanotubes and Nanowires Aligning Crossing Waving Coiling and

Twisting

Ernesto Joselevich Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Nanometer-scale materials can have unique properties due to their reduced dimensions and serve as building

blocks for the assembly of miniature functional systems In macroscopic functional systems wires tubes and

rods play critical roles of transporting energy forces matter and information Which materials could play

analogous roles at the smallest possible scale In order to find answers to this question we address two central

issues (1) How to control the properties of nanotubes and nanowires (2) How to organize nanotubes and

nanowires to enable their scalable integration into practical devices Regarding the first question rather than

sticking to the characterization of their basic properties we are interested in the relationship between different

properties For instance how a mechanical deformation changes the electrical properties of nanotubes Or how

an optical signal is translated into an electrical response Regarding the second question rather than ordering

disordered ensembles we investigate processes that lead to the spontaneous formation of ordered nanotubes

and nanowires We found that interactions with certain surfaces lead to the ldquoguided growthrdquo of nanotubes and

nanowires with well-defined geometries including perfectly aligned horizontal arrays grids serpentines and

coils These processes enable the self-integration of nanowires into functional systems (eg logic circuits

photodetectors) via guided growth In relation to the first question we investigate what happens when a

nanotube is twisted Carbon and inorganic nanotubes reveal different and intriguing torsional electromechanical

phenomena including quantum oscillations stick-slip behavior and ultra-high stiffness These phenomena

serve as the basis for nanoelectromechanical systems (NEMS) including tiny torsional resonators with potential

applications as nanogyroscopes This talk will give an overview of our research during the last fifteen years to

celebrate the award of the Tenne Prize in Nano Science at the 82nd Israel Chemical Society Meeting

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

30

Keynote Lecture

Self-assembly of Ultrashort Peptides and Metabolites From Biology to

Nanotechnology and Back

Ehud Gazit Department of Molecular Microbiology and Biotechnology Department of Materials Science

and Engineering Tel Aviv University Tel Aviv Israel

Bio-inspired nanotechnology is a key front in the field of molecular self-assembly of new structures and

composite families at the nano-scale Concept and notions from biological self-assembly could allow the design

and fabrication of nanomaterials while molecular self-assembly paradigm could be applied to biological

systems Our work on the mechanis m of aromatic peptide self-assembly lead to the discovery that the

diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length

Other aromatic homodipeptides (including those with non-coded amino acids as DOPA) could self-assemble in

nano-spheres nano-plates nano-fibrils and hydrogels with nano-scale order The modification of peptide

building blocks with the Fmoc protecting group allows the formation of hydrogels with nano-scale order We

demonstrated that the peptide nanostructures have unique chemical physical and mechanical properties

including ultra-rigidity as aramides semi-conductive piezoelectric and non-linear optic properties We also

demonstrated the ability to use these peptide nanostructures as casting mould for the fabrication of metallic

nano-wires and coaxial nano-cables The application of the nanostructures was demonstrated in various fields

including electrochemical biosensors tissue engineering and molecular imaging We had developed ways for

depositing of the peptide nanostructures and their organization We had use inkjet technology as well as vapour

deposition methods to coat surface and from the peptide ldquonano-forestsrdquo We recently demonstrated that even a

single phenylalanine amino-acid can form well-ordered fibrilar assemblies of distinct electron diffraction

pattern and toxic properties The combination of DNA properties and peptide backbone in the form of Peptide

Nucleic Acid (PNA) resulted in light emitting assemblies that exhibit both stacking and Watson-Crick base-

pairing We recently extended our studied to single amino acids and metabolites We established the concept

that even these entities can form well-ordered assemblies with amyloid like properties including ultrastructural

morphology toxicity leading to apoptosis ThT-binding and Congo-red birefringence

Selected References 2016

Levin A Michaels T C T Adler-Abramovich L Mason T O Mueller T Mahadevan L Gazit E amp

Knowles T P J (2016) Elastic Instability-Mediated Actuation by a Supramolecular Polymer Nature Physics

12 926-930

Arnon Z Vitalis A Levin A Michaels T Caflisch A Knowles TPJ Adler-Abramovich L amp Gazit

E (2016) Dynamic Microfluidic Control of Supramolecular Peptide Self-Assembly Nature Commun 713190

Guterman T Kornreich M Stern A Adler-Abramovich L Porath D Beck R Shimon L amp Gazit E

(2016) Formation of Bacterial Pilus-Like Nanofibers by Designed Minimalistic Self-Assembling Peptides

Nature Commun 713482

Mondal S Varenik N Bloch DN Atsmon-Raz Y Adler-Abramovich L Shimon L J W Miller Y

Regev O amp Gazit E (2016) A Minimal Length Rigid Helical Peptide Motif Allows Rational Design of

Modular Surfactants Nature Commun (in press)

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

31

Targeting the Toxic Oligomers of Amyloidogenic Proteins by Self-assembled

Cyclic DL-α-Peptides Potential Application for Alzheimerrsquos and Parkinsonrsquos

Diseases

Shai Rahimipour Department of Chemistry Bar-Ilan University Ramat-Gan Israel

Protein misfolding and aggregation is the fundamental cause of more than 20 amyloidogenic diseases affecting

either the central nervous system or a variety of peripheral tissues Although peptides and proteins of various

sequences can self-assemble into toxic amyloid structures they share common three-dimensional features that

may promote their cross-reaction Given the significant structural and biochemical similarities between

amyloids and the architecture of self-assembled cyclic DL-α- peptides we hypothesized that the latter may

bind and stabilize the nontoxic forms of different amyloids thereby preventing their aggregation into toxic

forms By screening an unbiased library of six-residue cyclic DL-α-peptides and optimizing the activity of a

lead peptide we found one cyclic DL-α-peptide (CP-2) that interacts strongly with Alzheimerrsquos disease

associated Amyloid beta (Aβ) and inhibits its aggregation and toxicity Further studies including Thioflavin T

assays electron microscopy and circular dichroism spectroscopy collectively suggest that CP-2 could also

effectively cross-interact with Parkinsonrsquos disease associated α-synuclein (α-syn) prevent its aggregation and

remodels its fibrils to non-toxic amorphous species through an ldquooff pathwayrdquo mechanism NMR studies show

that CP-2 interacts with the N-terminal and the non-Aβ component region of α-syn which are responsible for

α-synrsquos membrane interactions and self-assembly and so changes its conformation Dot-blot and cell survival

assays suggest that CP-2 reduces the amount of toxic α-syn oligomers and protects PC-12 and SH-SY5Y cells

from α-syn induced toxicity Moreover CP-2 permeates cells through endosomeslysosomes co-localizes with

intracellular a-syn and reduces its accumulation and toxicity in neuronal cells overexpressing α-syn Our studies

suggest that targeting the common structural conformation of amyloids may be a promising approach for

developing new therapeutics for amyloidogenic diseases

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

32

Fluorescent Ruthenium Complexes Based on 22rsquo-Bipyridine Modified

Peptoids

Galia Maayan Schulich Faculty of Chemistry Technion - Isreal Institute of Technology Haifa Israel

N-substituted glycine oligomers ldquopeptoidsrdquo are a class of peptidomimetics that are generated from primary

amines rather than from amino acids Thus their facile and efficient synthesis on solid support enables the

incorporation of various functional groups at specified N-positions along their spine Capitalizing on this

property we designed and generated helical peptoid sequences incorporating 22rsquo-bipyridine (bipy) which is a

widely used bidentate chelator capable of forming complexes with various metal ions Herein we demonstrate

that such peptoids form Ru(II) complexes via intermolecular binding to three linear peptoid strands or

intramolecular binding to a cyclic scaffold Ru(II) binding promoted changes in the conformational order of the

peptoids and chiral induction from the peptoids to their metal center was observed1 These Ru(II)peptoid

complexes however did not show significant fluorescence properties similar to their parent Ru(bipy)3

complex Our investigations show that a methoxy group bridging between the bipy and the peptoid backbone

result quenching of the complexes Thus we also describe two approaches to overcome this problem (1) the

use of hereroleptic Ru(II) complexes that include a bipy modified peptoid and bipy or 110-phenanthroline

(Phen) ligands and (2) the use of homoleptic Ru(II) complexes with only bipy modified peptoids in which the

methoxy bridge was modified We demonstrate that these two approaches lead to fluorescent Ru(II)peptoid

complexes with quantum yields that are comparable to these of Ru(bipy)3 and Ru(bipy)2Phen complexes

Reference

1] M Baskin L Panz and G Maayan Chem Commun 2016 52 10350-10353

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

33

Overcoming the Lack of Stereocomplementarity within Ene-reductases

The Chemoenzymatic Synthesis of all Four Stereoisomers of

2-Methylbutane-13-diol

Marvin Rafael Mantel1 Elisabeth Ruumlthlein1 Thomas Classen2 Joumlrg Pietruszka12 1Institute for Bioorganic Chemistry Heinrich-Heine-UniversityDuumlsseldorf at the Research

Center Juumllich Juumllich Germany 2Institute of Bio - and Geosciences Research Center Juumllich Juumllich Germany

The chemoenzymatic synthesis of small molecules can provide perfect stereoselectivity where organic methods

only supply a certain level of enantiopurity However enantiocomplementary enzymes are not always

accessible preventing chemoenzymatic synthesis from becoming a versatile tool in accessing all stereoisomers

of a desired product [1]

Herein we present an approach to overcome this problem by dexterous substrate-design instead of exhausting

catalyst-engineering Two different substrates converted by the same ene-reductase enable access to

enantiocomplementary products Next to the original substrate lsquomirroredrsquo starting material can be converted in

a similar stereospecific fashion Afterwards chemical modification of the residues following the enzymatic

reaction causes a priority-switch of the residues granting access to the missing isomers

All remaining stereogenic information is installed by ADHs matching the advantages of classic organic

methods and biocatalysis within a truly chemoenzymatic synthesis to all possible stereoisomers perfectly

[1] (a) E Ruumlthlein T Classen L Dobnikar M Schoumllzel J Pietruszka Adv Synth Catal 2015 375 1775-

1786 (b) Enzyme Catalysis in Organic Synthesis Vol 1 Wiley-VCH Verlag amp Co KGaA Weinheim

Germany 2012

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

34

Strategy for the Development of Non-toxic Antimicrobial Cationic

Amphiphiles

Kfir B Steinbuch Department of Organic Chemistry Tel Aviv University Tel Aviv Israel

Fungal infections are an increasing problem both in Western medicine and in regions with limited healthcare

availability Mortality due to invasive fungal diseases likely exceeds that of tuberculosis or malaria with

Candida albicans and Candida glabrata as the most frequently treated opportunistic fungal pathogens Inspired

by antimicrobial cationic peptides we have developed several families of synthetic antimicrobial cationic

amphiphiles We demonstrated that by manipulating structural motifs it is possible to enhance their selectivity

for microbial rather than mammalian red blood cell membranes To date none of the reported cationic

amphiphiles exhibited membrane selectivity sufficient to be considered for development of membrane-

disrupting antifungal agents

Here in we report that the incorporation of cis-double bonds into the lipids of cationic amphiphile significantly

decrease their hemolysis and toxicity against mammalian cells We demonstrated that increasing the degree of

cis-unsaturation in the lipid of antifungal cationic amphiphiles does not affect their antifungal activity against

Candida and decreases their hemolytic activity as well as their mammalian cell toxicity One of the cationic

amphiphiles with a linolenic acid lipid residue containing three cis-double bonds displayed no cytotoxicity

against a panel of mammalian cell lines and primary cells This compound selectively eradicated C albicans

cells while not affecting the viability of human cells in co-culture experiments Our findings offer a new

promising strategy for the development of non-toxic antimicrobial cationic amphiphiles safe for systemic

antifungal treatment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

35

Coiled Coil Protein Based Smart Surfaces Implementing Orthogonal Logic

Operations

Chiara Glionna1 Nurit Ashkenasy2 Gonen Ashkenasy1 1Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

2Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

Recently the gap facilitating the utility of molecular logic systems for application in technological fields was

reduced after the implementation of molecular logics on solid surfaces where molecules functionalizing the

surface are designed to respond to specific inputs Coiled coil protein assemblies are suggested here as new

candidates for this task due to their versatile properties and functionalities[1] Here we present reversible

surface attachment-detachment processes involving coiled coil proteins and describing orthogonal logic

operations Coiled coil peptides have been designed synthesized and characterized in solution by circular

dichroism and fluorescence spectroscopies Several reversible binding and releasing folding and unfolding

processes of heterodimeric coiled coil proteins have been performed on silicon nitride and gold surfaces The

surface layer was characterized by ellipsometry fluorescence and contact angle after each step These

programmable reactions have been performed demonstrating Boolean logic operation The coiled coil peptides

were labelled with a FRET couple allowing the parallel implementation of two- and three-input logic gates

NOR-OR and AND-ANH-NAND following monolayer thickness donor quenching and wettability as readout

The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly

on solid surfaces Surface properties can be dynamically dictated by functionalization with appropriate designed

proteins depending on the targeted device application This new approach of programmable manipulation of

synthetic proteins on solid surface can pave the way to the development of more effective and flexible

biosensing devices

[1] C Shlizerman A Atanassov I Berkovich G Ashkenasy and N Ashkenasy J Am Chem Soc 2010 132

5070-5076

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

36

Identifying Small Protein Populations by a Combinatorial

Fluorescent Molecular Sensor

Zohar Pode1 Ronny Peri-Naor1 Joseph Georgeson2 Tal Ilani2 Vladimir Kiss3

Tamar Unger4 Leila Motiei1 David Margulies1 1Organic Chemistry Weizmann Institute of Science Rehovot Israel 2Structural Biology Weizmann Institute of Science Rehovot Israel

3Biomolecular Sciences Weizmann Institute of Science Rehovot Israel 4Israel Structural Proteomics Center Weizmann Institute of Science Rehovot Israel

In recent years a growing number of cross-reactive sensor arrays that can recognize proteins in a non-selective

manner have emerged Although various differential sensors of this class have been developed and used to

discriminate among proteins these systems are less suitable for analyzing specific populations of proteins in

their native environment Cell-penetrating unimolecular sensors on the other hand are very specific and can

only detect one target at a time In this study we developed a unimolecular sensor that can detect different

proteins by generating unique identification patterns similarly to cross-reactive arrays We have shown that its

unimolecular scaffold and selective binding enable the combinatorial sensor to identify combinations of

proteins within complex biological mixtures and track several binding interactions simultaneously

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

37

Keynote Lecture

London Dispersion Effects in Molecular Chemistry ndash Reconsidering Steric

Effects[1]

Peter Richard Schreiner Institute of Organic Chemistry Justus-Liebig University Giessen Germany

The Gecko can walk up a glass window because of the adhesion in hydrophobic setae on its

toes that convey van der Waals (vdW) interactions with the surface The attractive part of such vdW-

interactions is an electron correlation effect referred to as London dispersion London dispersion has been

underappreciated as an element of structural stability reactivity and catalysis For increasingly larger

strucshytures the overall dispersion contribution grows rapidly and can amount to tens of kcal molndash1 This

presentation shows selected examples that emphasize the importance of inter- and intramolecular dispersion for

molecules consisting mostly of first row atoms2 We note the synergy of experiment and theory that now has

reached a stage where dispersion effects can be examined in fine detail

(1) Wagner J P Schreiner P R Angew Chem Int Ed 2015 54 12274

(2) a) Wende R C et al Angew Chem Int Ed 2016 55 2719 b) Roumlsel S Balestrieri C Schreiner P R

Chem Sci 2016 c) Prochaacutezkovaacute E et al Angew Chem Int Ed 2016 in press d) Fokin A A et al J Am

Chem Soc 2012 134 13641 e) Schreiner P R et al Nature 2011 477 308 f) Grimme S Schreiner P R

Angew Chem Int Ed 2011 50 12639 g) Fokin A A Gerbig D Schreiner P R J Am Chem Soc 2011

133 20036

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

38

Chiral Micro and Nano Sized Polymeric Particles Synthesis and Applications

Yitzhak Mastai Department of Chemistry and the Institute of Nanotechnology Bar-Ilan University

Ramat-Gan Israel

One of the greatest challenges in modern chemical processing is that of achieving enantiospecific control over

molecular chirality Discovering efficient methods to produce control and identify enantiomerically pure chiral

compounds is critical for the further development of many applications in various In recent years chiral

polymeric particles1 (micro and nano sizes) receives attention for their potential applications in many chiral

processes such as stereoselective synthesis separation of chiral compounds and optical activity In this lecture

we present our approach1-6 for the preparation of chiral micro and nano sized polymeric particles based on

miniemulsion polymerization of N-acryloyl amino acids monomers In figure below the SEM images of this

new type of chiral polymeric nanoparticles is shown Using this approach we have prepared lager set of amino

acids based chiral nanoparticles Moreover we will present our results on the use of those chiral polymeric

particles for few chiral applications such as chiral crystallization and stereoselective synthesis Finally we will

describe a new method to study the energetics of chiral interactions in chiral polymeric particles based on the

use of isothermal titration calorimetry (ITC)

Figure 1 (A) HR- SEM images of amino acid-cased chiral nanoparticles (B) SEM images of chiral -L-

phenylalanine microspheres

References

Medina D D Goldshtein J Margel S Mastai Y Advanced Functional Materials 2007 17 944-

950

Paik P A Gedanken and Y Mastai Journal of Materials Chemistry 20 (20)4085-4093

Preiss L C L Werber V Fischer S Hanif K Landfester Y Mastai and R Munoz-Espi Advanced

Materials 2016 27 (17)2728

Adler S R and Y Mastai Reactive amp Functional Polymers 2016 961-4

Werber L L C Preiss K Landfester R Munoz-Espi and Y Mastai Chirality 27 (9)613-618

Preiss L C Wagner M Mastai Y Landfester K Muntildeoz-Espiacute R Macromolecular Rapid

Communications 2016 37 (17) 1421-1426

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

39

Enzymes and Catalysis ndash Insights from Valence Bond

Avital Sharir-Ivry Varatharaj Rajapandian Avital Shurki

Institute for Drug Research School of Pharmacy The Hebrew University of Jerusalem

Jerusalem Israel

Understanding enzyme catalysis and developing ability to control it is one of the greatest challenges of

biochemistry to date Few successful examples of computational based enzyme design proved the fantastic

potential of computational approaches in this field Yet relatively modest rate enhancements were reported and

further development of complementary methods is still required The significant progress of the VB

methodology within 21st century enabled in turn great progress in the field of enzyme catalysis12 Our work

offers a conceptually simple scheme to identify the specific role that each residue within the enzyme plays in

catalysis The scheme is based on breakdown of the total catalytic effect into contributions of individual protein

residues which are further decomposed into chemically interpretable components using valence bond The

scheme will be demonstrated It will be shown to shed light on the origin of catalysis in wild-type haloalkane

dehalogenase and its mutants Furthermore a set of simple rules to select non-optimal sites for catalysis will be

described along with possible choice of effective mutations to enhance the enzymatic rate

References

1] Sharir-Ivry A Shnerb T Štrajbl M amp Shurki A VBMM protein landscapes a study of the SN2

reaction in haloalkane dehalogenase Phys Chem B 114 2212-2218 (2010)

2] Sharir-Ivry A Rajapandian V amp Shurki A Valence Bond and Enzyme Catalysis A Time to

Breakdown and a Time to Buildup Eur J 21 7159-7169 (2015)

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

40

Anodic Degradation of Amide Bonds

James Y Becker Tatiana Golub-Sedinkin

Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

The amide bond is one of the most common bonds in nature and is known to be strong and stable

thermodynamically Typically the anodic oxidation of amides affords a side-chain oxidation-substitution

product at the a position to `N` [1] leaving the amide moiety intact

The present work describes that specific amides lacking hydrogen(s) at the a position to `N`

undergo three types (A B and C below) of anodic bond cleavage in acetonitrile [2]

The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent

attached to the aryl group The type of products obtained and the mechanism involved will be discussed as well

as the outcome from `cyclic amides` [3]

References

[1] H Lund and M Baizer (Eds) Organic electrochemistry an introduction and guide 3rd ed Marcel

Dekker Inc 1990 pp 1550

[2] T Golub and JY Becker Org Biomol Chem 2012 10 3906

[3] T Golub J Y Becker J Electrochem Soc 2013 160 (7) G3123

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

41

Keynote Lecture

Sonochemistry of Molten Metals

Aharon Gedanken Zeev Porat Vijay Bhooshan Kumar

Chemistry Bar-Ilan University Ramat-Gan Israel

When a sonochemical horn is placed in molten metals covered by silicon oil a precipitate is formed in a few

minutes despite the temperature being above the metal`s melting point This method fits metals whose mp is

lower than 430 0C namely Hg Ga In Pb Sn Cd Bi and Zn In the case of Ga whose melting point is 298 0C

water can be used as the overlayering the molten Ga The reaction that is carried with water can be conducted at

60 0C (30 degrees above the melting point) and still a solid precipitates to the bottom of the test tube The

reason is a film that is formed on the metal surface preventing a liquid to be formed For Ga we have

encapsulated organic molecules in the metal and even imprented chirality in Ga For the seven metals an

organic liquid is used above the metal the coated layer was a film of carbon The supernatant is composed of

small C-Dots and more interesting nanoparticles of MetalC-dot were also found in the supernatant The

doped C-Dots were characterized by all the conventional Materials Science techniques such as XRD HRTEM

HRSEM ICP and more We were able to vary the doping level by changing the amount of the metal used C-

Dots are well-known for their fluorescence properties and the emission spectrum of the MetalC-Dots is

different from that of pristine C-Dots A few examples of the application of the metal dopes C-Dots will be

demonstrated For example GaC-dots showed very good biocidal properties against Pseudomonas

aeruginosa The metalC-Dots were used in catalysis as well as in building electrodes for rechargeable Li

batteries

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

42

Nano-Lithographically Directed Organization at the Molecular Scale

from Inorganic Nano-Architectures to Bio-Interfaces

Mark Schvartzman14 Guillaume Le Saux14 Avichai Marcovici14 Viraj Bhingardive14

Yossi Keidar14 Pazit Rukenstein24 Taleb Mokari24 Angel Porgador3 1Materials Engineering Ben-Gurion University of the Negev Beer-Sheva Israel

2Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel 3Immunology and Genetics Ben-Gurion University of the Negev Beer-Sheva Israel

4Ilse Katz Institute for Nanoscale Science and Technology

Ben-Gurion University of the Negev Beer-Sheva Israel

Nanoimprint lithography is a rapidly emerging technique for high-throughput nanopatterining with the

resolution down to the molecular scale Recently we developed novel concepts for nanoimprint lithography

based on soft mold with rigid relief features allowing high flexibility of patterning on non-standard substrates

without compromising on the pattern fidelity We use these nanofabrication advances to produce high-

resolution templates through which we implement hybrid top-downbottom-up approach for the nanoscale

structuring of matter as well as for the nanoscale control of molecular assemblies at bio-interfaces In the first

application we produce templates for the controlled surface organization of CdSe-Au nanodumbbells The

templates consist of nanoimprinted arrays of Au nanodots functionalized with thiol-terminated self-assembled

monolayers Here the functionalized dots serve as natural docking points for the Au tips of the nanodumbbells

enabling the formation of higher 2D architectures in which the nanodumbbells serve as the basic building

blocks In the second application we functionalize the nanodot arrays with ligands for transmembrane receptors

of cells to produce bio-chips with biomimetic artificial microenvironment that controls the spatial arrangement

of the receptors within the cell membrane Here efforts have been made on producing bi-functional ligand

arrays that selectively control two types of receptors These bio-chips are used to study and control the spatial

cross talk between different adhesion ligands in stem cells as well as the spatial cross-talk between the

activating and inhibitory receptors in Natural Killer (NK) and T-cells

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

43

Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Roie Yerushalmi Institute of Chemistry The Hebrew University of Jerusalem Jerusalem Israel

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional

building blocks Synthetic strategies for attaining well-definedheterogeneity in structure shape composition

and modulation of the electronic structure at selected regions of the nano system is therefore highly desired I

will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as

the basic building blocks The synthesis yield hybrid nanostructures with well-defined morphologies by

triggering a programmable cascade of events that is autonomously executed and terminated termed lsquoself-

processing synthesisrsquo The self-processing synthesis is demonstrated for preparing coinage metal Au Ag and

Cu -semiconductor hybrid nanostructures The synthesis involves a sequence of selective etch and deposition

steps which are self-initiated and self-terminated resulting in the hybrid nanostructures The hybrid

nanostructures obtained for the coinage metals resemble the morphology of grass flowers termed here Nano-

floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell

cap The new class of structures is useful in a variety of applications owing to the unique geometrical aspect

ratio and electronic properties of the hybrid systems

Reference

J Am Chem Soc 138 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu Ag and Au

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

44

Graphitic Carbon Nitride Layers as Light-Harvesting Semiconductors for

Photoelectrochemical Cells

Menny Shalom Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

One of the most promising future sources of alternative energy involves water-splitting photoelectrochemical

cells (PECs) ndash a technology that could potentially convert sunlight and water directly to a clean

environmentally-friendly and cheap hydrogen fuel Practical PEC-mediated hydrogen production requires

robust and highly efficient semiconductors which should possess good light-harvesting properties a suitable

energy band position stability in harsh condition and a low price Despite great progress in this field new

semiconductors that entail such stringent requirements are still sought after

Over the past few years graphitic carbon nitride (g-CN) has attracted widespread attention due to its

outstanding electronic properties which have been exploited in various applications ndash including in photo- and

electro-catalysis heterogeneous catalysis CO2 reduction water splitting light-emitting diodes and PV cells g-

CN comprises only carbon and nitrogen and it can be synthesized by several routes Its unique and tunable

optical chemical and catalytic properties alongside its low price and remarkably high stability to oxidation (up

to 500 degC) make it a very attractive material for photoelectrochemical applications However to date only a

few reports regarded the utilization of g-CN in PECs due to the difficulty in acquiring a homogenous g-CN

layer on a conductive substrate and to our lack of basic understanding of the intrinsic layer properties of g-CN

In this talk I will introduce new approaches to grow g-CN layers with altered properties on conductive

substrates for photoelectrochemical application The growth mechanism as well as their chemical

photophysical electronic and charge transfer properties will be discussed

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

45

Keynote Lecture

Understanding Molecular and Hybrid Crystals from First Principles

Leeor Kronik Materials and Interfaces Weizmann Institute of Science Rehovot Israel

Molecular crystals are crystalline solids composed of molecules bound together by relatively weak

intermolecular interactions typically consisting of van der Waals interactions andor hydrogen bonds Hybrid

crystals combine molecular units and covalentionic networks Both classes of crystals play an important role in

many areas of science and engineering ranging from biology and medicine to mechanics and electronics

Therefore much effort has been dedicated to understanding their structure and properties

Predicting the behavior of such materials from first principles is highly desired for understanding their unique

properties and for allowing rational design of novel materials and structures Preferably we would like to

obtain such understanding from density functional theory (DFT) because the relative computational simplicity

afforded by DFT allows us to attack realistic experimentally accessible problems Unfortunately despite many

other successes DFT has traditionally struggled with useful prediction of properties of crystals that contain

weakly-bound units

Here I will show how state-of-the-art DFT approaches allow us to overcome these limitations quantitatively I

will focus on our recent progress in explaining and even predicting important classes of collective effects ie

phenomena that the individual units comprising the crystal do not exhibit but arise through their interaction

Specifically I will address unique structural mechanical electrical and optical properties of both biogenic and

synthetic crystals with an emphasis on constructive interaction between theory and experiment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

46

Quasiparticle Solitons in an Extended Bose-Hubbard Dimer Array with

Dipolar Interactions

Amichay Vardi Amit Dey

Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva Israel

Considering a two-dimensional Bose-Hubbard spinor lattice with weak nearest neighbour interactions and no

particle transfer between sites we theoretically study the transport of energy from one initially excited dimer to

the rest of the lattice For weak on-site interaction the excited sitersquos energy is quickly dispersed throughout the

array However beyond a critical on-site interaction strength the excitation becomes self trapped and localized

energy breathers and solitons are observed These are quasiparticle analogues to the discrete two dimensional

solitons in photonic lattices Exact quantum simulations give similar results with the expected smoothing of the

transition due to the finite energy variance

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

47

The Transition Path Time Distribution - Protein Folding Quantum

Mechanics Tunneling Times and Uncertainty

Eli Pollak Chemical Physics Weizmann Institute of Science Rehovot Israel

The recent experimental measurement of the transition path time distributions of proteins [1] presents theory

with several challenges Foremost why do the fits of the experimental data to a theoretical expression lead to

barrier heights which are much lower than the free energies of activation of the observed transitions Secondly

what is the transition path time distribution without invoking the Smoluchowski limit Thirdly what are the

properties of a quantum transition path time distribution and may they be used to present a new parafigm for

understanding the concpet of time in quantum mechanics In this talk I will introduce the concept of a transition

path barrier to explain the experimental results [2] as well as the concept of a quantum mechanical transition

path time probability distribution The properties of these distribution including quantum tunneling times and

its relation to position momentum uncertainty will be discussed

[1] Neupane K Foster DAN Dee DR Yu H Wang F Woodside MT Direct Observation of Transition

Paths During the Folding of Proteins and Nucleic Acids Science (2016) Vol 352 239-242

[2] Pollak E The transition path time distribution and the transition path free energy barrier Phys Chem

Chem Phys (2016) Vol 18 28872 ndash 28882

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

48

Biogenic Twinned Crystals Exhibiting Unique Morphological Symmetry

Anna Hirsch1 Dvir Gur2 Benjamin Palmer2 Steve Weiner2 Lia Addadi2 Leslie Leiserowitz1

Leeor Kronik1 1Department of Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Department of Structural Biology Weizmann Institute of Science Rehovot Israel

Guanine crystals are widely used in nature as components of multilayer reflectors Organisms control the size

morphology and arrangement of these crystals to obtain a variety of optical ldquodevicesrdquo [1] The reflection

systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered

reflectors are tiled together to form a contiguous packed array In the former square crystals are tiled to form a

reflecting mirror In the latter hexagonal crystals are closely packed to produce brilliant colors Based on

electron diffraction morphology considerations and density functional theory these crystals were shown to

possess similar monoclinic crystal symmetry which we have previously identified as different from that of

synthetic anhydrous guanine [2] However the crystals are different in that multiple twinning about the 012

and the 011 crystallographic planes results in square and hexagonal morphology respectively This is a

unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry

than that of the underlying crystal allowing for tiling that facilitates optical functionality

[1] D Gur B Palmer S Weiner and L Addadi Light Manipulation by Guanine Crystals in Organisms

Biogenic Scatterers Mirrors Multilayer Reflectors and Photonic Crystals Advanced Materials (2016) in

press

[2] A Hirsch D Gur I Polishchuk D Levy B Pokroy A J Cruz-Cabeza L Addadi L and Leslie

Leiserowitz ldquoGuanigmardquo The Revised Structure of Biogenic Anhydrous Guanine Chemistry of Materials

2015 27 (24) 8289-8297

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

49

Nanotubes Motion on Layered Materials A Registry Perspective

Inbal Oz Itai Leven Yaron Itkin Asaf Buchwalter Katherine Akulov Oded Hod

Department of Chemistry Tel Aviv University Tel Aviv Israel

Abstract At dry and clean material junctions of rigid materials the corrugation of the sliding energy landscape is

dominated by variations of Pauli repulsions These occur when electron clouds centered around atoms in

adjacent layers overlap as they slide across each other In such cases there exists a direct relation between

interfacial surface (in)commensurability and superlubricity a frictionless and wearless tribological state The

Registry Index is a purely geometrical parameter that quantifies the degree of interlayer commensurability thus

providing a simple and intuitive method for the prediction of sliding energy landscapes at rigid material

interfaces In the present study we extend the applicability of the Registry Index to non-parallel surfaces using

a model system of nanotubes motion on flat hexagonal materials Our method successfully reproduces sliding

energy landscapes of carbon nanotubes on Graphene calculated using a Lennard-Jones type and the

Kolmogorov-Crespi interlayer potentials Furthermore it captures the sliding energy corrugation of a boron

nitride nanotube on hexagonal boron nitride calculated using the h-BN ILP Finally we use the Registry Index

to predict the sliding energy landscapes of the heterogeneous junctions of a carbon nanotubes on hexagonal

boron nitride and of boron nitride nanotubes on graphene that are shown to exhibit a significantly reduced

corrugation For such rigid interfaces this is expected to be manifested by superlubric motion

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

50

Bitter or Not BitterPredict- Tool for Predicting Taste from Chemical

Structure

Ayana Dagan-Wiener12 Masha Y Niv12 1Institute for Biochemistry Food Science and Nutrition The Robert H Smith Faculty of

Agriculture Food and Environment The Hebrew University of Jerusalem Rehovot Israel 2Fritz Haber Center for Molecular Dynamics The Hebrew University of Jerusalem Jerusalem

Israel

Bitter taste is a significant factor in animalrsquos choice of food Animals avoid eating bitter food components

many of which are toxic Nevertheless it is known today that bitterness is not always noxious and that some of

the bitter compounds have beneficial effects on health Interestingly bitter taste receptors are also expressed in

many extraoral tissues and emerge as novel targets for therapeutic indications such as asthma and infection

Bitter compounds (gathered in the BitterDB httpbitterdbagrihujiacildbbitterphp) dramatically vary in their

structures Therefore identifying bitter molecules based on their chemical structures is a very challenging task

Here we present a machine learning classifier BitterPredict which predicts whether a molecule is bitter or not

based solely on its chemical structure To this end we used BitterDB as the true positives set non-bitter

molecules that were gathered from literature and enriched by random molecules as true negative set

physicochemical and ADMETOX descriptors for the molecules and Adaboost (decision tree based) algorithm

BitterPredict correctly classifies over 85 of the compounds in the hold-out test set and between 70 to 90

of the compounds in three independent external sets The fraction of sp3-hybridized (tetrahedral) carbon atoms

out of total carbon count (Fsp3) and Hydrophobic component of the saturated carbon and attached hydrogen

(FOSA) descriptors are the most important contributors to the classifier

Interestingly but not surprisingly the classifier suggests that a small portion (10) of compounds found in

food and a large portion (70) of clinical and experimental drugs are bitter

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

51

Development in the DFT Estimates of Magnetic Couplings in Chromium-

Based Molecular Rings from an Optimally-Tuned Range separated Hybrid

Functional

Shira Weissman1 Michal Antkowiak2 Grzegorz Kamieniarz2 Leeor Kronik1 1Materials and Interfaces Weizmann Institute of Science Rehovot Israel

2Faculty of Physics A Mickiewicz University Poznan Poland

The Cr8 molecule as well as its homo- and hetero-metallic derivatives belongs to a class of molecular

nanomagnets which are extensively studied for a number of fundamental aspects and envisaged applications

However estimating accurately their magnetic couplings from first principles calculations has proven to be

difficult Here we present progress in this area for two prototypical molecular rings Cr8 and Cr7Ni- using

density functional theory with an optimally-tuned range separated hybrid (OT-RSH) functional This approach

has been shown to allow for an accurate description of the electronic structure in a variety of more simple

molecular systems Here we show that it is also capable of producing highly accurate magnetic exchange

parameters for both molecules despite their complexity while improving the overall description of the

electronic structure especially with respect to the energy of the frontier orbitals For the Cr7Ni- ring the values

of the magnetic couplings found are distinguished by a unique site distribution and lead to excellent agreement

with experiment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

52

Building Fullerenes and Nanotubes - From Carbon Clusters to Modular

Origami

Yoni Toker Physics Bar-Ilan University Ramat-Gan Israel

One of the pivotal moments in the history of nanotechnology was the experimental discovery of the

Buckminster Fullerene in 1985 for which Smalley Kroto and Curl recieved the 1996 Nobel Prize in

Chemistry We will tell the story of this amazing discovery and explore the fascinating science of fullerenes and

nanotubes which spans many disciplines including chemistry physics technology and recreational

mathematics We will also explore means by which fullerenes and nanotubes structures can be constructed in

the classroom using beads and strings (a technique known as beaded molecules) or with modular origami

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

53

Is it Possible to Evaluate the Learning Process of Students in Chemistry

Laboratory Courses

Ruthy Sfez Advanced Materials Engineering Azrieli College of Engineering Jerusalem Israel

For many decades laboratory courses have been an integral and central part in any curriculum of students

learning for science or engineering degrees During the years laboratory courses` goals have changed

dramatically and sophisticated and advanced experiments were introduced However it is still difficult to

evaluate the performance of students in laboratory courses and to get an insight on the learning curve of the

practical work aspect It is well known that laboratory courses require a major effort on behalf of the students

The main reason for that is the combination of several understanding levels and skills which are needed and

graded The final grade in a laboratory course can be roughly divided into preparation performance and

reporting The student` preparation and reporting parts can be easily evaluated by regular methods However

the assessment of the students` experimental work which is an essential part of the final grade and the

monitoring of the experimental work learning curve is very difficult to achieve

In order to deal with this problem we have developed in the past years rubric scores both for students and

teaching assistants (TAs) which are based on chosen parameters From the TAs point of view the rubric score

enables a systematic and standardized grading of the performance of students in Chemistry` laboratory courses

From the students` point of view it helps non verbal understanding of the skills which are expected to be

developed during the course Comparison of the two rubrics scores enables to give formative assessment in real

time along with improvement of the studentTA interface and some insight on the learning process of the

students

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

54

Chemists` Vision of Chemistry-Related Profession

Or Shav-Artza1 Yehudit Judy Dori12 1Faculty of Education in Science and Technology Technion - Israel Institute of Technology

Haifa Israel 2Samuel Neaman Institute Technion - Israel Institute of Technology Haifa Israel

Chemistry is one of the important disciplines for Hi-Tech and other advanced industries These industries need

passionate educated and skilled personnel For years there has been a shortage of chemists in Israel and this

lack is likely to grow in the coming years Therefore there is a continuously growing number of studies related

to promoting a career in chemistry

Our research is based on the Social Cognitive Career Theory (SCCT) which provides explanations on how

career and academic interests mature how career choices are made and how these choices are turned into

action The goal of this study is to explore chemists` vision of the chemistry profession and their perception

toward chemical education We identify factors that influenced chemists to pursue a chemistryndashrelated career

by analyzing their self-reported experiences while they were students as well as in their chemistry industrial

profession Data collection is conducted by (a) individual semi-structured interviews and (b) questionnaires

with open- and close-ended questions The research participants are about 30 professionals in chemical and

pharmaceutical industries in Israel Our sample is diverse as it includes men and women in high- and

intermediate-level positions The Research questions include (a) What are the main factors for choosing one`s

chemistry-related career (b) What are the differences if any between men and women in choosing a

chemistry-related career Preliminary results will be presented and discussed This research is expected to

provide recommendations for encouraging high school students to choose chemistry as a major and

undergraduate students to choose chemistry-related career

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment

55

Natural Gas and Renewable Energy Sources in the Twelfth Grade

Eran Shmuel Chemistry Rothberg High School Ramat Hasharon Israel

The 70-30 reform brought to mind many considerations on the subject of ldquosignificant learningrdquo especially in

the chemistry subject that calls for significant learning all year long both in the laboratory lessons and the

theoretical ones Transferring the optional unit that was studied in the twelfth year to the 30 program created

for us the teachers the chance to design for ourselves subject matters that are more relevant to everyday life

This includes instilling skills such as public speaking online searching individual and group studies witho For

us to teach with a great passion that will pass on to the students we need to teach the subjects that are best

suited to us In my lecture I will present a program that was developed for the twelfth year students in Rotberg

high school in Ramat Hasharon that combines teaching natural gas and renewable energy sources with

thermodynamics and environment