program detail abstract booklet - dallas-fort worth local...

Program Detail

& Abstract Booklet

Organized By

Department of Chemistry & Biochemistry

Dallas-Fort Worth Section of the American Chemical Society

50

th Annual Meeting-in-Miniature

Saturday, April 29, 2017


50th Annual Meeting-in-Miniature Organized By: Department of Chemistry & Biochemistry, TCU

Important information

The meeting will be held on Saturday, 29th April 2017 in TCU's Sid W.

Richardson Physical Sciences Building (http://www.maps.tcu.edu/)

You can park in any white-lined space on campus. The lots across the street

from Sid W. Richardson Physical Sciences Building and the Lot 15 on W.

Lowdin St. between Lubbock and Merida Avenues are recommended

(http://www.maps.tcu.edu/)

Presenters must copy their presentation to the computer available in each

session room. Please arrive early to have your presentation loaded into the

computer from your flash drive/disc and to address any technical

difficulties

All session rooms will have Screen, Projector, VGA, HDMI Cables (If you want

to use your own Laptop)

Be aware of your time as you will be held to the time allotted. Allow 3-5

minutes for questions from audience which must be included in your total

time allotment. You may also make yourself available to answer questions

after the session

If you are unable to present on your scheduled day/time, notify by email at

[email protected] or at [email protected]

Prepared By Arshad Mehmood Graduate Student Computational Chemistry, TCU.

http://www.maps.tcu.edu/

http://www.maps.tcu.edu/

mailto:[email protected]



50th Annual Meeting-in-Miniature Organized By: Department of Chemistry & Biochemistry, TCU

Table of Contents

Schedule At-A-Glance 01

Section 1

Undergraduate 1 02

Undergraduate 2 10

Undergraduate 3 17

Section 2

Inorganic/Materials Chemistry 1A 24



Section 3

Inorganic/Materials Chemistry 1B 45



Section 4

Organic/Analytical Chemistry 1 66



Section 5

Organic/Biochemistry 1 88



Section 6

Physical/Computational Chemistry 1 111



Presenters Index 133


50th Annual Meeting-in-Miniature Organized By: Department of Chemistry & Biochemistry, TCU 1


50th Annual Meeting-in-Miniature

Schedule At-A-Glance

Section 1 2 3 4 5 6

Venue LH* 1 LH 3 LH 2 LH 4 SWR 446 SWR 360

Category Undergraduate

1

Inorganic/ Materials

1A


1B

Organic/ Analytical 1

Organic/ Biochem.

1

Physical/ Computational

1

08:45-09:00 Patel Ren Brown McCabe Miller Niedbalski

09:00-09:15 Orr Oswald Melancon Pathiranage Davis Najafian

09:15-09:30 Barrera Mayberry Ponduru Asgari J. Cao Montelongo

09:30-09:45 Nance Yaseen Kamras Chinthala Noonikara Wang

09:45-10:00 Barnett Wilk Sotelo Hu Ojo Jones

10:00-10:15 Ravi Lin Ivy Yellappa Nagar Parveen

10:15-10:30 Zometa Vizuet Jayathilaka Barragan Mudasiru Parish

Break

Undergraduate 2


2A


2B


Organic/ Biochem.

2


2

11:00-11:15 Young Y. Cao Korir Mammoottil Aljowni Wang

11:15-11:30 Schostag Harris Johnston Avullala Alahakoon Nazemi

11:30-11:45 Reeves Brewer Almotawa Budy Dakarapu Medel

11:45-12:00 Samuel Palacios Buford Gayan Seal II Lyu

12:00-12:15 Villegas Perera Williams Shao Chunduru Sun

12:15-12:30 Howlett Benton MacKenzie Ryan Green Oliveira

Lunch

Undergraduate 3


3A


1B


Organic/ Biochem.

3


3

01:30-01:45 Agbo Otten Shennara Singh Ochoa Tao

01:45-02:00 Martin Vaish Omer Herath Bunton Ranathunga

02:00-02:15 Burge Farvid D’Achille Thapa Kale Zhou

02:15-02:30 Quimbar Benavides Sardar H. Nguyen Castillo Kim

02:30-02:45 Foley D. Nguyen Kumar Gobeze Obondi Shen

02:45-03:00 Weber - - Bokka Montoya Humason

03:00-03:15 - - - - Sharma -

03:15-03:45 Judging

03:30-04:15 Tours

04:15-05:00 Awards-LH 1 *Sid W. Richardson Physical Sciences Building: Lecture Hall



Section 1

Undergraduate 1 Sid W. Richardson Physical Sciences Building: Lecture Hall 1

Time Presenter Title

08:45-09:00 Shreya Patel Southern Methodist University

A Volumetric Three-Dimensional Digital Light Photoactivatable Dye Display

09:00-09:15 Melissa Orr University of Texas at Arlington

Synthesis of Inorganic Pigment ALn2S4 (A= Ca, Sr, Ba; Ln= La, Ce, Pr)

09:15-09:30 Maribel Barrera University of North Texas

Solubility of sorbic acid in organic mono-solvents: calculation of Abraham model solute descriptors from measured solubility data

09:30-09:45 Patricia Nance Southern Methodist University

Synthesis and Characterization of Antibacterial Polyphosphazene Materials

09:45-10:00 Maddie M. Barnett Texas Christian University

Determining the antioxidant activity of small metal-binding ligands that target agents known to lead to neurodegenerative diseases

10:00-10:15 Sanjana Ravi University of Texas at Dallas

Synthesis of Silica Centipede Nanoparticles for Drug Delivery Purposes

10:15-10:30 Diego F. Zometa Abilene Christian University

The first molecular square containing eight osmium atoms

Undergraduate 1 Sid. Richardson Lecture Hall 1



A Volumetric Three-Dimensional Digital Light Photoactivatable Dye Display

Shreya Patel, Jian Cao, Alexander R. Lippert*

Department of Chemistry, Southern Methodist University

E-mail: [email protected]

Category: Undergraduate

Division: Organic Chemistry

Three dimensional (3D) displays have captivated the minds of many, and with science fiction movies like

Star Wars, Iron Man, and Avatar, 3D displays have become synonymous with the future of imaging

technology. Aside from the entertainment industry, 3D displays could have significant applications in

medical, architectural, mathematical, and even chemical modeling as visualization tools. Due to complex

fabrication requirements, it is incredibly difficult to generate 3D images, and so 3D imaging techniques

are not currently commonplace. We report a new technique of volumetric 3D imaging, the 3D digital

light photoactivatable dye display (3D Light PAD). The 3D Light PAD relies on a small photoswitching

molecules that fluoresce at the intersection of visible light and UV light. By manipulating beams of light

using a commercial picoprojector and a projector fitted with a UV LED, we have been able to generate

3D images and animations with a minimum voxel size of 0.68 mm3, 200 µm resolution, and stability over

an extended amount of time. This technique of imaging is easy to operate and relatively inexpensive. The

synthesis, characterization, and the technique of the 3D Light PAD will be presented.





Synthesis of Inorganic Pigment ALn2S4 (A= Ca, Sr, Ba; Ln= La, Ce, Pr)

Melissa Orr, Adriana Paolo Sotelo, Dr. Robin T. Macaluso*

Department of Chemistry and Biochemistry, University of Texas at Arlington



Division: Solid State/Inorganic Chemistry

Current inorganic pigments raise real world issues such as the cost and danger of synthesis, toxicity,

and environmental safety. Additionally, recent federal regulatory legislation has sparked interest in the

importance of finding new non-toxic high-performance pigments to be used in plastics, paints, and

ceramics, especially in the red color range. A few rare-earth sulfides have been used for this purpose,

however, their synthesis presents challenges for large scale implementation. This work examines ALn2S4

(A= Ca, Sr, Ba; Ln= La, Ce, Pr) as promising pigment materials and presents a novel synthesis route

which eliminates the flow of toxic and corrosive gases and complex heating processes.





Solubility of sorbic acid in organic mono-solvents: calculation of Abraham model solute descriptors from measured solubility data

Maribel Barrera, William E. Acree*

Department of Chemistry, University of North Texas



Division: Analytical Chemistry

Experimental mole fraction solubilities are reported for sorbic acid dissolved in methanol, ethanol, 1-

propanol, 1-butanol, 1-pentanol, 1-hexanol, 2-propanol, 2-methyl-2-propanol, 2-pentanol, diisopropyl

ether, methyl tert-butyl ether, tetrahydrofuran and 1,4-dioxane at 298.15 K. Results of the experimental

measurements, combined with a published water-to-octanol partition coefficient and published solubility

data for sorbic dissolved in acetone, ethyl acetate and acetonitrile, were used to calculate Abraham

model solute descriptors for the sorbic acid monomer. The calculated solute descriptors were found to

describe the measured solubility and partition coefficient data to within 0.10 log units. The calculated

solute descriptors can be used to predict sorbic acid solubilities at 298.15 K in additional organic

solvents in which sorbic acid is expected to exist predominately in monomeric form.





Synthesis and Characterization of Antibacterial Polyphosphazene Materials

Patricia Nance, Patty Wisian-Neilson*




Division: Inorganic Chemistry

Properties of the polyphosphazene, [RR'PN]n, can be selected for specific purposes by post

polymerization modification of the side groups, R and R', which are attached to the polymeric backbone

via phosphorus carbon bonds. Poly(methylphenylphosphazene) (PMPP) is among the most extensively

studied of these alkyl/aryl polyphosphazenes, which are synthesized by condensation polymerization of

N-silylphosphoranimines. PMPP is most easily modified by deprotonation of the methyl group followed by

substitution of electrophiles. This ongoing work explores the use of this method to substitute

antibacterial groups onto the polyphosphazene backbone so that they may be used as infection-

preventing films for biomedical applications. Thus far, two immediate precursors to antibacterial

polyphosphazenes have been synthesized and characterized, and the methodology for the final synthetic

step to each polymer is being developed. Additionally, experiments were performed to increase percent

substitution of the precursor groups to yield effective antibacterial group substitution levels.





Determining the antioxidant activity of small metal-binding ligands that

target agents known to lead to neurodegenerative diseases

Maddie M. Barnett, Hannah. M. Johnston, Kayla N. Green*

Department of Chemistry and Biochemistry, Texas Christian University




Oxidative stress in the brain is a known contributor to the development of neurodegenerative diseases,

including Alzheimer’s. The focus of this project is to target the amyloid-β plaque formations and reactive

oxygen species (ROS) derived from mis-regulated metal-ions that lead to disease-causing oxidative

stress. The present investigation is measuring the antioxidant reactivity of the new molecule L4. L4

contains two radical scavenging pyridol groups along with a metal-binding nitrogen rich ligand system. It

was hypothesized that increasing the number of pyridol groups in our small molecule library would

increase the radical scavenging activity, which in turn may provide cells protection from oxidative

stress. The radical scavenging ability of L4 was quantified using the 2,2-diphenyl-1-picrylhydrazyl (DPPH)

radical assay and this was compared to other radical scavenging small molecules to evaluate the effect

of the additional radical scavenging group on the antioxidant activity. The interaction of L4 with redox

active metal-ions such as copper(II) was also evaluated to show the molecule’s ability to target

misregulated metal-ions in diseased tissues.





Synthesis of Silica Centipede Nanoparticles for Drug Delivery Purposes

Sanjana Ravi, Jason Lin, Kenneth Balkus Jr.*

Department of Chemistry, University of Texas at Dallas




Today, most cancer patients are treated with nonspecific antitumor drugs that are distributed

throughout the body following intravenous injections. These drugs attack both healthy and cancerous

tissue, causing a weakened immune system, among many other effects. By using a wrinkled silica coated

magnetic core, tumors can be directly targeted. While synthesizing wrinkled silica, silica structures,

named centipedes were observed. These centipedes contain a smooth surface with legs protruding from

the surface. Since the centipede has a width of 30 nm, the centipede can fit inside the pores of tumorous

tissues and deliver chemotherapy drugs. This, along with its chemical and thermal stability makes it

optimal for drug delivery purposes.

The current synthesis for these centipedes is by using urea, cetylpyridinium bromide, water, cyclohexane

and tetraethyl orthosilicate. Since centipedes have not been published, the correct environment under

which only centipedes form is still being discovered. Currently, we are bubbling carbon dioxide into the

cetylpyridinium bromide in order to change the structure and pH of the surfactant, leading to a slightly

different template and hopefully creating these centipede structures. After solidifying the conditions, we

can coat magnetic cores with these centipedes to target tumors and make cancer treatment more

effective.





The first molecular square containing eight osmium atoms

Diego F. Zometa, Dr. Gregory L. Powell*

Department of Chemistry and Biochemistry, Abilene Christian University




Based on the ability of ruthenium carbonyl to combine with dicarboxylate anions to form triangular and

square macrocycles consisting of dimetal sawhorse units, we have been investigating reactions of

osmium carbonyl with dicarboxylic acids. Significantly higher temperatures are required to activate the

Os–C bonds in osmium carbonyl compared to the Ru–C bonds in ruthenium carbonyl, but with the use

of a microwave heating, one triangular hexanuclear osmium sawhorse complex was recently prepared

in our lab. We decided to attempt the syntheses of additional macrocyclic complexes by reacting

Os3(CO)12 with 1,3-adamantanedicarboxylic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid in

a microwave reactor. The X-ray crystal structures of three different products from these reactions will

be presented. The product with 2,6-naphthalenedicarboxylate ligands is the first example of a molecular

square with eight osmium atoms. The other products include a tetranuclear molecular loop and a

hexanuclear molecular triangle.




Section 1



11:00 -11:15 Mackenzie Young Southern Methodist University

Synthesis and Characterization of Polyphosphazenes with Pyridine Substituents

11:15-11:30 Kelly Schostag Southern Methodist University

A Novel Synthesis of Thiols Under Mild Conditions

11:30-11:45 Audrey Reeves Southern Methodist University

Imaging Acetaldehyde Formation During Ethanol Metabolism in A549 Cells using a Hydrazinyl Naphthalimide Fluorescent Probe

11:45-12:00 Anthony B. Samuel University of Texas at Dallas

Determining the structural stability of single crystalline Ln3Co2Sn7 (Ln = La-Nd, Sm, Gd)

12:00-12:15 Hector Villegas Texas Christian University

Intramolecular nonbonded attractive interactions

12:15-12:30 Thomas Howlett University of Texas at Dallas

Synthesis of Holmium Iron Garnet Nanoparticles coated with wrinkle silica and periodic mesoporous organoslica for Cancer Treatment




Synthesis and Characterization of Polyphosphazenes with Pyridine Substituents

Mackenzie Young, Patty Wisian-Neilson*





Polyphosphazenes, [RR'PN]n, are inorganic polymers with a broad range of properties largely determined

by the nature of the groups R and R' attached to the phosphorus in the PN backbone.

Poly(alkyl/arylphosphazenes) are prepared by thermolyis of Si-N-P compounds which contain simple alkyl

and aryl P–C bonded groups. The simplest and best studied of these is poly(methylphenylphosphazene),

PMPP, 1, where the methyl group is readily modified by deprotonation-substitution reactions. The

intermediate polymer anion, 2, formed by deprotonation reacts with several types of electrophiles

allowing for incorporation of new functionality and subsequent alteration of properties of the polymeric

materials. In this study, the electrophile pyridine carboxaldehyde was used to attach pyridine groups

which offer both metal coordination sites and potential bioactivity to the polymer system. The synthetic

conditions, characterization by NMR spectroscopy, and potential applications of this new polymer

system will be discussed.

n-BuLi

n

P N

Ph

CH3

yx

P N

Ph

CH2

P N

Ph

CH3Li+

_

N C

O

H

P N

Ph

CH3

P N

Ph

CH2

C OHH

N

x y

..

1 2 3





A Novel Synthesis of Thiols Under Mild Conditions

Kelly Schostag, David Son*





Thiols have shown great usefulness in many fields for a variety of purposes including being used as

stabilization agents, in synthesizing other compounds, and as protective coatings. Unfortunately, thiols

have limited commercial availability due to the harsh conditions under which they are synthesized. Past

research in the Son Lab has shown that some thiols can be synthesized with high yields under milder

conditions by reacting a trithiocarbonate sodium salt with a brominated compound. Here we study these

methods of thiol synthesis in order to verify the past results and expand the number of thiols synthesized

with these procedures. There are two methods used in the past study: one uses heat to accelerate the

reaction, and the other uses a phase transfer catalyst. In our report we focus on the latter method. We

confirmed this method can be used to synthesize thiols, but at nowhere near a commercial level quantity.

In the future, we will continue to study this method using different phase transfer catalysts, and expand

our study to include other halogenated compounds as starting materials.





Imaging Acetaldehyde Formation During Ethanol Metabolism in A549 Cells using a Hydrazinyl Naphthalimide Fluorescent Probe

Audrey Reeves, Alexander Lippert*




Division: Chemical Biology

Acetaldehyde plays a notorious role as a toxic intermediate in the enzymatic metabolism of ethanol. The

undesired side effects of this metabolism – headache, nausea, dry mouth, vertigo, and sensitivity to light

and sound – mark the well-known symptoms of a hangover. However, due to the challenges associated

with the study of small molecules in living cell metabolism, the precise biochemical events that lead to

these pathologies remain unclear. Here, we have visualized the metabolism of ethanol to acetaldehyde

in living lung epithelial cells using a hydrazinyl naphthalimide fluorescent probe. Utilizing a condensation

reaction between carbonyls and a hydrazine moiety, we demonstrate that the fluorescent probe AF1

reacts with a range of reactive carbonyl species including formaldehyde, acetaldehyde, glyoxylic acid, and

methyl glyoxal. We have applied AF1 towards the visualization of acetaldehyde generated from alcohol

dehydrogenase mediated ethanol metabolism, validating it as a useful tool to study the roles of alcohol

in respiratory disease and other pathological mechanisms.





Determining the structural stability of single crystalline Ln3Co2Sn7 (Ln =

La-Nd, Sm, Gd)

Anthony B. Samuel, Thomas J. Martin, Julia Y. Chan*

Department of Chemistry, The University of Texas at Dallas,




As part of our study to determine the structural stability of stannide intermetallics, we report the

synthesis, crystal growth and characterization of Ln3Co2Sn7 (Ln = La-Nd, Sm, Gd). By taking advantage of

a eutectic point of the lanthanide and cobalt, we are able to synthesize the desired phase at

temperatures lower than the reactants’ melting point. We first arc-melt the constituents, then grind the

product into a fine powder prior to characterization of our sample by X-ray diffraction. In this

presentation, I will present the structural details and discuss future work in our effort to grow single

crystals of the Ln3Co2Sn7 phase.





Intramolecular nonbonded attractive interactions

Hector Villegas, Benjamin G. Janesko*

Department of Chemistry & Biochemistry, Texas Christian University



Division: Physical/Computational Chemistry

While cis/Z-substituted alkenes are usually less stable than their trans/E-substituted counterparts, the

cis-2-butenyl anion shows a higher preference over the trans-isomer. Calculations suggest that the

discrepancy is due to two cooperating effects: electrostatic interactions between the anionic center (C1)

to the methyl group (C4) and coupling between the C=C pi* antibonding orbital and both the CH2 pz and

CH3 C-H sigma bonds. Supporting the charge transfer is the fact that substitution on C1 with EDG

stabilizes the cis more while substitution on C4 with EWG stabilizes the cis more. For the coupling

interaction the C=C bond was stretched which increased the cis stabilization by lowering the pi* orbital

energy and increasing the coupling between the lone pair on C1 and pi*.





Synthesis of Holmium Iron Garnet Nanoparticles coated with wrinkle silica and periodic mesoporous organoslica for Cancer Treatment

Thomas Howlett, Jason Lin, Kenneth Balkus Jr.*





The Holmium Iron Garnet (HoIG) nanoparticle has shown to be an effective delivery system for

chemotherapy while also being a source of radiation to eliminate cancer cells in a tumor. An exciting

addition to this is using Periodic mesoporous organosilica (PMO) to coat HoIG for more efficient drug

delivery. An important aspect of the PMO is that the surface area and functional groups can be changed

to work with hydrophobic and hydrophilic drugs. This can be expanded on by using a wrinkle silica

structure to improve overall surface area. The method for both the PMO and the wrinkle silica is to coat

a thin template layer of silica on the HoIG using TEOS. Then coat the surfactant, CPB or CTAB, to act as

the template for the next coating of silica to make a wrinkle structure. The final step for the PMO

synthesis is to add a mixture of benzylsilane and TEOS to achieve a wrinkled PMO structure. So far this

method has been successful in coating although loading and unloading has not been tested yet. The

future steps in this would be to shrink the particle size overall and continue to improve the coating

method.




Section 1



01:30 -01:45 Christiana Agbo Tarrant County College South Campus

Determination of alcohol content in beverages using nuclear magnetic resonance spectroscopy

01:45-02:00 Misty S. Martin University of Texas at Arlington

Matrix-assisted laser desorption/ionization time-of-flight – mass spectrometry for the characterization of groundwater microbiomes

02:00-02:15 Joshua Burge Tarrant County College South Campus

Characterization of fatty acid compositions of monovarietal olive oils from the Kalamata, Tuscan, and Sicilian regions using NMR Spectroscopy and Gas Chromatography

02:15-02:30 Miguel E. Quimbar Southern Methodist University

A chemiluminescent platform for smartphone monitoring of H2O2 in human exhaled breath condensates

02:30-02:45 Brandon J. Foley Southern Methodist University

Botrytis Cinerea Vivid Wild-Type and Mutant LOV Protein Photocycle Kinetics

02:45-03:00 Samuel Weber Southern Methodist University

Optogenetic System to Interrogate the Fungal Circadian Clock




Determination of alcohol content in beverages using nuclear magnetic resonance spectroscopy

Christiana Agbo, Olga Papadopoulou, Martha Gilchrist*

Department of Natural Science, Tarrant County College South Campus




Ethanol, produced by fermentation of sugars, is the principal alcoholic component in alcoholic beverages

with concentrations ranging from 3% in beer to 50% v/v in spirits. Gas Chromatography (GC), fractional

distillation and spectrophotometry are analytical methods often used to quantify alcohol in beverages.

We have utilized the Magritek 43 MHz 1H-NMR spectrometer to determine the alcohol content in

beverages using the method published by Isaac-Lam et al. (Isaac-Lam, M. 2016). A calibration curve

was constructed and acetonitrile was used as an internal standard. Beverages including beer, wine, and

distilled liquor were analyzed and our data are in agreement with the manufacturer’s label.





Matrix-assisted laser desorption/ionization time-of-flight – mass spectrometry for the characterization of groundwater microbiomes

Misty S. Martin1, Inês C. Santos1,3, Doug D. Carlton, Jr.1,3, Zacariah L. Hildenbrand2,3, Kevin A.

Schug1,3*

1Department of Chemistry and Biochemistry, University of Texas at Arlington.

2Inform Environmental, LLC, Dallas TX.

3Affiliate of the Collaborative Laboratories for Environmental Analysis and Remediation, University of

Texas at Arlington.




Groundwater is the main drinking water source in America. Hence, it is important to maintain its quality.

A major concern is the possible contamination of groundwater from unconventional oil and gas drilling.

Environmental stressors can contribute to the evolution of pathogenic microorganisms, which pose as

a health concern as groundwater provides a method of dissemination for antibiotic-resistant

microorganisms. Therefore, it is necessary to understand the impacts of contaminants on the

groundwater microbiome. Molecular techniques are used to characterize microbial ecology, but are

expensive and time-consuming. Matrix-assisted laser desorption/ionization (MALDI) time-of-flight –

mass spectrometry (TOF MS) is a significant alternative, because it is more rapid and cost-efficient. In

this work, the groundwater microbiome was assessed in contaminated groundwater using MALDI-TOF

MS. The bacteria were isolated using the membrane filter technique and cultured in selective media.

Identifications were confirmed through gene sequencing. Antibiotic susceptibility was determined.

Twenty-five bacteria were identified using MALDI-TOF MS. Of these, over 90% matched the sequencing

results. Overall, samples exhibiting the highest levels of contamination appeared to facilitate the growth

of pathogenic bacteria including, A. hydrophila, B. cereus, P. aeruginosa and S. maltophilia. These four

were resistant to most of the antibiotics tested.





Characterization of fatty acid compositions of monovarietal olive oils

from the Kalamata, Tuscan, and Sicilian regions using NMR

Spectroscopy and Gas Chromatography

Joshua Burge, Pei Eng, Olga Papadopoulou, Martha Gilchrist*

Department of Natural Science, Tarrant County College South Campus




Olive oil has been cultivated in the Mediterranean since ancient times, and is a principal ingredient in the

Mediterranean diet. Recently, monovarietal olive oils have experienced increased consumer interest for

their distinctive flavor characteristics. In this study, gas chromatography and Nuclear Magnetic

Resonance spectroscopy are utilized to compare three monovarietal olive oils and to determine if these

methods can be used to differentiate between olive oils cultivated in these particular regions. GC analysis

indicates that the major fatty acids present in the three monovarietal EVOO’s are palmitic, oleic, and

linoleic. From our analysis, no statistical differences in their percent compositions are observed.

Preliminary NMR data suggest that one EVOO may be distinguishable based on aliphatic region

integration values.





A chemiluminescent platform for smartphone monitoring of H2O2 in human exhaled breath condensates

Miguel E. Quimbar, Alexander R. Lippert*

Dedman College, Southern Methodist University




Noninvasive measurement of oxidative markers in clinical samples has the potential to rapidly provide

information for disease management, but is limited by the need for expensive analytical instrumentation

that precludes home monitoring or point-of-care applications. We have developed a simple to use

diagnostic platform for airway hydrogen peroxide (H2O2) that combines optimized reaction-based

chemiluminescent designs with an inexpensive home-built darkbox and readily available smartphone

cameras. Specialized photography software applications and analysis of pixel intensity enables

quantification of sample concentrations. Using this platform, sample H2O2 concentrations as low as 264

nM can be detected. The platform has been used to measure H2O2 in the exhaled breath condensates

of human subjects, showing good agreement with the standard Amplex Red assay.





Botrytis Cinerea Vivid Wild-Type and Mutant LOV Protein Photocycle

Kinetics

Brandon J. Foley, Haley Stutts, and Brian D. Zoltowski*

Department of Chemistry, Center for Drug Discovery, Southern Methodist University




Blue-light photosensors are a type of LOV domain that sense light quantity and relay a signal to adapt to

constant levels or respond to changes in the environment. The signal transduction in response to light

stimuli involves protein:protein interactions that attenuate gene expression related to circadian clocks.

VVD is a specific type of LOV domain that was cloned into the Botrytis Cinerea fungal pathogen that

infects a variety of agricultural products. The pathogenicity of Botrytis Cinerea LOV proteins is blue light

and circadian clock dependent. In this study, we characterized Botrytis Cinerea VVD photocycle kinetics

with respect to base catalysis and temperature dependence for both wild-type protein and rate affecting

variants (T194I). Base catalysis with imidazole was found to accelerate the rate of recovery identically

for the T194I mutant and the wild-type protein. Eyring and Arhenius analyses indicated a single rate

limiting step in the thermal reversion with a moderate enthalpy of reaction and largely unfavorable

entropy of reaction for the T194I mutant.





Optogenetic System to Interrogate the Fungal Circadian Clock

Samuel Weber, Brian Zoltowski*




Division: Biochemistry

Organisms have developed circadian oscillators to allow adaptation to daily fluctuations in light-intensity,

metabolic resources and oxidative stress. The regulatory networks integrating these factors are

inherently complex, involving numerous components and multiple interconnected biological circuits.

Currently, analysis of such complex systems is limited to two general approaches. First, one can isolate

individual components and perform biochemical analysis to identify their functional role. Such an

approach affords keen insight into chemical regulation, but is limited in its ability to decipher how input

from multiple components is integrated on a systems-level. The alternative systems biology approach

incorporates networkwide analysis through mathematical modeling. The systems approach allows

insight into the global regulatory network, but is limited in its incorporation of fundamental chemistry.

Herein, we devise an alternative approach that allows interrogation of the entire network in the context

of the fundamental chemistry. Specifically, we devise an optogenetic system recapitulating the fungal

circadian clock. Through mutations that affect protein:protein interactions, light-regulated protein

allostery, and alteration of photochemical input we interrogate the integration of blue-light and oxidative

stress into the fungal circadian clock.




Section 2

Inorganic/Materials Chemistry 1A Sid W. Richardson Physical Sciences Building: Lecture Hall 3


08:45-09:00 Yixin Ren University of Texas at Dallas

Neodymium based Complexes bearing Phosphate Ligands for Living Ring Opening

Polymerization of ε-Caprolactone and D, L-

lactide

09:00-09:15 Iain W. H. Oswald University of Texas at Dallas

Resolving Crystallographic Disorder in Intermetallics Adopting the Yb3Rh4Sn13-Structure Type

09:15-09:30 Darrell D. Mayberry University of North Texas

Asymmetric Catalysis by Chiral Metal Clusters

09:30-09:45 Waleed Yaseen University of North Texas

Hydrophobic Fluorinated Polymers for Corrosion Protection on Aluminum Surface

09:45-10:00 Mikaela Wilk Texas Woman’s University

Synthesis and characterization of novel copper phenanthroline complexes: Tuning the structure and photophisics via alteration of the synthetic route

10:00-10:15 Jason Lin University of Texas at Dallas

Wrinkled Periodic Mesoporous Organosilica Nanoparticles for Hydrophobic Drug Delivery

10:15-10:30 Juan P. Vizuet University of Texas at Dallas

Metal-organic Frameworks in Polymeric Membranes for Gas Separations

Inorganic/Materials Chemistry 1A Sid. Richardson Lecture Hall 3



Neodymium based Complexes bearing Phosphate Ligands for Living

Ring Opening Polymerization of ε-Caprolactone and D, L-lactide

Yixin Ren, Stephanie T. P olderman, Trinh D. Vo, Michael C. Biewer and Mihaela C. Stefan*

Department of Chemistry and Biochemistry, University of Texas at Dallas


Category: Graduate

Division: Polymer Chemistry

Neodymium-based complexes bearing phosphate ligands NdCl3·3L (L = triethyl phosphate (TEP) or

tris(2-ethylhexyl) phosphate (TEHP) were successfully synthesized. The ring opening polymerization

(ROP) of ε-caprolactone (ε-CL) and D, L-lactide (LA) initiated with these complexes in the presence

of a series of alcohols were performed yielding polymers with narrow polydispersity index (PDI =

1.22 to 1.47) and well-defined molecular weights. An important result from the kinetic studies

revealed that the sterically bulkier ligand TEHP as compare to TEP ligand scientifically increase the

rate for ROP of ε-CL. Di-block copolymers poly(ε-caprolactone)-block-poly(D, L-lactide) via sequential

monomers addition were successfully synthesized and demonstrated the livingness of the catalytic

system.





Resolving Crystallographic Disorder in Intermetallics Adopting the

Yb3Rh4Sn13-Structure Type

Iain W. H. Oswald,1 Binod K. Rai,2 Emilia Morosan,2 Julia Y. Chan1*

1Department of Chemistry and Biochemistry, University of Texas at Dallas

2Department of Physics and Astronomy, Rice University


Category: Graduate


Electrical and magnetic properties of solid-state materials are inherently tied to their structure and are

thus affected by defects or disorder. Presented herein is a crystallographic study on a series of

superconducting compounds, Ln3T4Ge13 (Ln = Y, Lu, Yb; T = Os, Ir, Co, Rh), adopting the Yb3Rh4Sn13-

structure type. This structure is modeled in the cubic space group Pm3̅n with lattice constant aprimitive ~

8.9 Å, consisting of corner sharing Ge icosahedra and transition metal trigonal prisms. Single crystal X-

ray diffraction experiments revealed anomalous elongated ellipsoids, indicating the presence of static

disorder. Additionally, weak, unindexed reflections were also observed in powder X-ray diffraction,

suggesting the structure has lower symmetry. A crystallographic model is proposed for the structure of

Ln3Ir4Ge13 (Ln = Lu, Yb) with tetragonal space group I41/amd, where atetragonal ~ 2aprimitive that accounts for

these distortions. Additionally, an empirical correlation between the semiconducting-like electrical

resistivity and atomic displacement parameters (ADPs) was found. These results suggest disorder,

quantified by ADPs, can be used as a new tool for predicting physical properties of a material.





Asymmetric Catalysis by Chiral Metal Clusters

Darrell D. Mayberry, Michael G. Richmond*

Chemistry Department, University of North Texas,


Category: Graduate


The reactions of 1-(3-(diphenylphosphino)ethylthiol)-2- (diphenylphosphino)benzene (dppet) and 1-(3

(diphenylphosphino)ethoxy)-2-(diphenylphosphino)benzene (dppeo) with (μ-H)2Ru3(μ3-S)(CO)9 along with

their corresponding chiral cluster products were investigated for use in asymmetric catalysis. The chiral

cluster products from the aforementioned reactions produced (μ-H)2Ru3(μ3-S)(CO)6(μ3-dppet) (1), (μ-

H)2Ru3(μ3-S)(CO)7(μ-dppet) (2), (μ-H)2Ru3(μ3-S)(CO)7(μ- dppeo) (3). Clusters 1, 2, and 3 were

characterized by NMR spectroscopy; in addition, X-ray diffraction analysis of cluster 1 was performed.

VT-NM spectroscopy confirmed the carbonyl ligand fluxionality in 13C-enriched clusters 1, 2, and 3.

Thermolysis was used to establish the conversion of cluster 2 to cluster 1. A catalytic mechanism

involving clusters 1, 2, and 3 was investigated by DFT calculations.





Hydrophobic Fluorinated Polymers for Corrosion Protection on

Aluminum Surface

Waleed Yaseen, Sreekar Marpu, Mohammad A. Omary*, Teresa Golden*



Category: Graduate


Hydrophobic and corrosion resistive coatings were successfully prepared by photopolymerization of

acrylate based fluorinated monomers. The coatings are directly cured on aluminum surface by simple

drop cast technique. Poly hexafluoroisopropyl methacrylate (PHFiPMA) and poly hexafluorobutyl

methacrylate (PHFBMA) were prepared by free radical photopolymerization method. Hexafluorobutyl

methacrylate (HFBMA) and hexafluoroisopropyl methacrylate (HFiPMA) were used as monomers,

hydroxycyclohexyl phenyl ketone (Irgacure 184) as a photoinitiator, and poly (ethylene glycol) diacrylate

as a cross-linker. These fluorinated polymers demonstrated highly corrosion protection characterized

by using Potentiodynamic polarization, open circuit potential (OCP), and electrochemical impedance

spectroscopy (EIS) techniques in 3.5% NaCl solution. Flourier transform infrared spectroscopy (FTIR)

and Scanning Electron Microscope (SEM) techniques were used to show the structure and the

morphology of the coatings surface. Dynamic contact angle test demonstrated the hydrophobicity of the

fluorinated polymers. Thermal stability for these polymers was measured by using thermogravimetric

analysis (TGA). The in-house photopolymerized fluorinated polymers exhibited strong chemical resistance

for strong acids and bases as well as resistance for wide range of solvents. Tape test method was used

as well to show the adhesion strength of these coatings on the aluminum surface. The in-house technique

for making these fluorinated corrosive coatings is highly economical compared to very expensive

commercial polymers of similar category.





Synthesis and characterization of novel copper phenanthroline complexes: Tuning the structure and photophisics via alteration of the

synthetic route

Mikaela Wilk, Shaquisha Scott, Daniella Vargas, Rebecca Johnson, Youstina Fateem, Vladimir

Nesterov, Manal Rawashdeh-Omary*

Department of Chemistry and Biochemistry, Texas Woman’s University


Category: Graduate


Copper is a low cost abundant metal that is currently being studied for potential application in many

fields including medicinal treatments, solar energy, and catalysis. The synthetic route plays an important

role in differentiating 4 new copper phenanthroline complexes. This presentation will give an overview

of the synthesis, crystal structures, and photophysical properties of these complexes. Infrared

spectroscopy, nuclear magnetic resonance spectroscopy, thermogravimetric analysis, X-ray

crystallography, and UV/Vis electronic absorption and luminescence spectral data will be presented for

the products of the different reactions attempted vs. the starting material.





Wrinkled Periodic Mesoporous Organosilica Nanoparticles for Hydrophobic Drug Delivery

Jason Lin, Kenneth Balkus Jr.*



Category: Graduate


There is a growing interest of utilizing mesoporous silica in numerous applications. Mesoporous silica

has several significant properties included high surface area, high capacity, tunable functionality, and

modifiable morphology. These characteristics make mesoporous silica a promising drug delivery

material.

Our wrinkled periodic mesoporous silica is basically synthesized through hydrothermal reaction with

TEOS and benzylsilanes. Two surfactants are used as template, CTAB and CPB which cause a significate

difference of the morphology. The particles size is normally around 100 nm after 24hr synthesis no

matter which surfactant is used. Recently, we are focusing on synthesizing bi-phenyl silanes wrinkle silica

which provides fluorescence property and can be used for imaging.





Metal-organic Frameworks in Polymeric Membranes for Gas Separations

Juan P. Vizuet, Kenneth J. Balkus*



Category: Graduate


Metal-organic frameworks (MOFs) are porous, stable and highly ordered materials with high surface

areas. By carefully selecting the metal center and the organic linker used in the framework we can tailor

the specific properties of the MOF to match gas separation applications. The downside of these

materials is their high cost of production, processability and low mechanical stability when used as stand-

alone membranes.

Polymeric membranes have the advantages of low cost, processability and mechanical stability but they

have a tradeoff between gas permeability and selectivity. To overcome this tradeoff strategies like

polymer blending or addition of inorganic additives, such as MOFs, have been used. Furthermore, our

research has demonstrated that by using MOFs in a blend of non-compatible polymers, we can control

the internal morphology of the membrane.

My research focuses on the synthesis of novel Metal-organic Frameworks to use as additives in polymer

blend membranes. Selection of the appropriate synthetic conditions and the type of functional groups in

the organic linker are key to obtain suitable materials that can be used as additives. After the synthesis

of the MOFs, construction of membranes is the next step in my research.




Section 2



11:00 -11:15 Yakun Cao Southern Methodist University

Synthesis and Utilization of 1-Chloro-2-methyl-1,8-benziodazol-3(2H)-one in the Preparation of Hyperbranched Polymers

11:15-11:30 Lauren M. Harris University of North Texas

Monovalent coinage metal diphosphine-based complexes as potential led phosphors for display technologies

11:30-11:45 Samantha M. Brewer Texas Christian University

Catalytic and mechanistic investigation of three tetra-aza macrocyclic iron(III) complexes

11:45-12:00 Philip M. Palacios University of Texas-Arlington

The Kinetic and Spectroscopic Characterization of 2-aminoethanethiol dioxygenase

12:00-12:15 Wijayantha A. Perera University of Texas at Dallas

Hydrothermal Synthesis of TiO2 Nanotube (TNT)/ RuO2 Nanoribbon (NR)/ Graphene Oxide Composites with Enhanced Photocatalytic Activity

12:15-12:30 Erin N. Benton University of North Texas

Sensing Silver Ion Leakage from Silver Nanoparticles




Synthesis and Utilization of 1-Chloro-2-methyl-1,8-benziodazol-3(2H)-one in the Preparation of Hyperbranched Polymers

Yakun Cao, Nicolay V. Tsarevsky*

Department of Chemistry and Center for Drug Discovery, Design, and Delivery at Dedman

College, Southern Methodist University


Category: Graduate


Hyperbranched polymers have received enormous amount of attention due to their unique properties

such as abundant functional groups, intramolecular cavities, low viscosity as well as their potential

applications in coatings, additives, drug and gene delivery. A new hypervalent iodine compound, 1-chloro-

2-hexyl-1,8-benziodazol-3(2H)-one (CHIO), was synthesized and utilized as both, an initiator and a transfer

agent, to prepare highly branched polymers with numerous alkyl chloride chain ends. CHIO can cleave

homolytically upon thermal conditions to produce chlorine radicals which can be utilized to polymerize

vinyl-monomers. Furthermore, in presence of propagating radicals, CHIO can act as transfer agent by

transferring the chlorine atom to the propagating chain. Thus, the facile synthesis of branched polymers

in high yields with significant delay in gelation was achieved. In addition, the effects on polymerization of

CHIO concentration, solvents and temperature were systematically investigated.




Monovalent coinage metal diphosphine-based complexes as potential

LED phosphors for display technologies

Lauren M. Harris, Mukunda M. Ghimire, and Mohammad A. Omary*



Category: Graduate


This work focuses on the design and syntheses of monovalent transition coinage metal-based functional

materials that exhibit potential to be used in energy applications, including energy saving, harvesting, and

storage. Finding efficient, low-cost phosphorescent materials based on these late transition metal

complexes has been a focal point of this study. Additionally, this work can possibly serve a number of

modern display technological applications, especially inorganic and organic light emitting diodes (LEDs

and OLEDs, respectively). Because of high spin−orbit coupling (SOC) induced by the coinage metal(I)

centers, and high radiative triplet decay rates if applied in OLEDs, these complexes can exploit both the

singlet and triplet excitons and, principally, can transfer them into light with 100% internal quantum yield.

The reaction of a monovalent coinage transition metal precursor with diphosphine ligands leads to the

corresponding coordination complexes in high yield. Synthetic details, single crystal X-ray solid-state

structures and other relevant characterization techniques such as NMR, FTIR, UV/Vis/NIR solution

absorption, solid-state diffuse reflectance, and solid-state photoluminescence spectroscopies will be

explored. These complexes exhibited blue, turquoise, and green photoluminescent emissions with high

quantum yields, which are desired properties to address the existing problems with respect to the blue-

light emission of LEDs and OLEDs.





Catalytic and mechanistic investigation of three tetra-aza macrocyclic iron(III) complexes

Samantha M. Brewer, Kayla N. Green*



Category: Graduate


Iron plays a pivotal role in metabolism and transport processes in nature but can also be used

to accomplish important chemical transformations on the bench top; recently, iron(II) salts have

been shown to catalyze direct Suzuki – Miyaura coupling of N-heterocyclic compounds and

arylboronic acid derivatives in the presence of oxygen. Presented herein are three tetra-aza

macrocyclic iron(III) complexes [L1Fe(III)(Cl)2]+ (L1Fe), [L2Fe(III)(Cl)2]+(L2Fe), and

[L3Fe(III)(Cl)2]+ (L3Fe) [L1 (Pyclen)=1,4,7,10-tetra-aza-2,6-pyridinophane; L2 =3,6,9,15-

tetraazabicyclo[9.3.1]penta-deca-1(15),11,13-trien-13-ol; L3 =3,6,9,15-tetra-

azabicyclo[9.3.1]penta-deca-1(15),11,13-trien-12-ol] that catalyze the coupling of pyrrole and

phenylboronic acid. Following the synthesis and reactivity studies, investigation into the oxidation

state of the iron center throughout the catalytic cycle was explored. The results of this work to

date will be presented and will facilitate the understanding of challenging chemical reactions

catalyzed using inexpensive earth abundant metals such as iron.





The Kinetic and Spectroscopic Characterization of 2-aminoethanethiol dioxygenase

Philip M. Palacios, Brad S. Pierce*

Department of Chemistry, University of Texas-Arlington


Category: Graduate


Non-heme enzymes have historically received strong interest in the field of bioinorganic chemistry due

to their widespread functionalities and structural diversity. 2-aminoenthanethiol dioxygenase (ADO) is a

non-heme, mononuclear iron enzyme that catalyzes the O2-depedent oxidation of cysteamine (CA) to

produce hypotaurine (HTau). Coincidentally, very little information is available in the literature regarding

the mechanism and characteristics of this enzyme. In this work, we present steady-state kinetics of ADO

with two different thiol substrates, cysteine (Cys) and cysteamine (CA) as a means to determine the

kinetics of the enzyme with its native substrate. Taken together with EPR spectroscopy, we present a

model for cysteamine oxidation.





Hydrothermal Synthesis of TiO2 Nanotube (TNT)/ RuO2 Nanoribbon

(NR)/ Graphene Oxide Composites with Enhanced Photocatalytic

Activity

Wijayantha A. Perera, Yuzhi Gao, Yves Chabal, Kenneth J.Balkus Jr*



Category: Graduate


Titanium dioxide is the most studied and widely used photocatalyst. In the presence of Uv light, it

generates electrons and holes that can act as a powerful oxidizing and reducing species. But 99% of

the generated electrons and holes recombine before they react with the pollutants. This will limit its

photocatalytic performance. Therefore, the goal is to minimize the electron-hole recombination. A new

method have been introduced to separate generated electrons and holes by using graphene oxide/

ruthenium oxide nanoribbons/ titanium dioxide nanotube composite. Different amounts of ruthenium

oxide nanoribbons and titanium dioxide nanotubes were grown on reduced graphene oxide and evaluated

its photocatalytic efficiency using malachite green oxalate dye. The composite with highest loading

showed excellent photocatalytic performance.





Sensing Silver Ion Leakage from Silver Nanoparticles

Erin N. Benton, Sreekar Marpu, Mohammad A. Omary*



Category: Graduate


Silver nanoparticles have many applications including drug delivery, antimicrobial behavior (numerous

products of which are available in the market), and biological imaging. There have been numerous

studies/debates on the toxicity of silver nanoparticles versus silver ions and it is believed by some that

the toxicity may be due to the decay of the nanoparticles into silver ions. A gold(I) complex has been

developed that has the ability to differentiate between silver ions and silver nanoparticles in aqueous

solution. It was shown that silver nanoparticles leak silver ions over time and the sensor developed can

sense that release. The lower detection limit of this sensor was found to be 13.5ppb and the upper

detection limit was found to be 26.3ppm, which is competitive with other silver sensors found in the

literature.




Section 2



01:30 -01:45 Brooke M. Otten University of North Texas

To Be or Not To Be: d10-d10 Bonding in Heterometallic Complexes

01:45-02:00 Avichal Vaish Southern Methodist University

Preparation of Self-healing & Dynamic Gels and Their Conversion to Non-Dynamic Gels using Hypervalent Iodine Compound

02:00-02:15 Seyed Majid Farvid University of North Texas

Improving the performance of prototypical bi-layer devices by a novel double-doping method

02:15-02:30 Katherine A. Benavides University of Texas at Dallas

Property-Driven Synthesis: The Relationship Between Structure and Properties of Ln2Fe4-xCoxSb5 (Ln = La – Pr; x < 1.5)

02:30-02:45 Do Nguyen University of Texas at Dallas

Improved Hydrogen Separation Performance of Mixed-Matrix Membranes based on Blend of Immiscible Polymers




To Be or Not To Be: d10-d10 Bonding in Heterometallic Complexes

Brooke M. Otten, Mohammad M. Omary*



Category: Graduate


Heterometallic and homometallic complexes of the form [MM`PCPx] (where M= Ni, Pd and Pt;

PCP=PH2CH2PH2 and x=2 or 3) have been modeled using density functional theory to determine if these

complexes display metal-metal bonding. While the homometallic complexes show conventional bond

orders of zero, the heterometallic complexes show bond orders that are not equal to zero. For all

complexes, the optimized geometries were examined to find metal-metal distances and Dunham analysis

was performed on the potential well to find the metal-metal vibrational frequencies. Orbitals were also

analyzed to determine the bond orders. In homometallic complexes, it was found that the mixing of nd-

nd orbitals give rise to 5 bonding orbitals and 5 antibonding orbitals while the heterometallic complexes

exhibit occupied non-bonding orbitals. The occupancy of the non-bonding orbitals leads to complexes with

shorter metal-metal distances and higher dissociation energies. However, the complexes with 3 bridging

ligands have shorter metal-metal distances which give stretching frequencies that are close to their 2

bridging ligand counterparts.





Preparation of Self-healing & Dynamic Gels and Their Conversion to Non-Dynamic Gels using Hypervalent Iodine Compound

Avichal Vaish, Nicolay V. Tsarevsky*



Category: Graduate


In modern organic chemistry, hypervalent iodine(III) compounds are frequently used as oxidizing agents

but application of λ3-iodanes in polymer and material chemistry is still underexplored. In this work, we

report on the preparation of dynamic and self-healing materials by employing ligand exchange reactions

involving hypervalent iodine(III) compounds of the type ArIL2 (Ar = Aryl, L = ligand, e.g., carboxylate or

(pseudo)halide). These compounds can undergo ligand exchange reactions in presence of nucleophiles

(Nu-) to form ArINu2. Diacetoxyiodo benzene (DAIB) was successfully employed as a crosslinker to

prepare dynamic and self-healing gels derived from carboxylate-containing polymers. Furthermore,

advantage was taken of the ability of DAIB to generate radicals upon UV light irradiation in order to

convert the dynamic crosslinked structures to permanent (set) networks.





Improving the performance of prototypical bi-layer devices by a novel

double-doping method

Seyed Majid Farvid, Dieaa Alhmoud, Musafa Kharma, Kurt Bodenstedt, Abdel Monem

Rawashdeh, and Mohammad A. Omary*



Category: Graduate


We have discovered that standard NPB/Alq3 bi-layer organic light-emitting diodes (OLEDs) – the

prototypical devices that revolutionized OLEDs since the 1980s – can undergo a significant

improvement in performance upon slight alteration of the device structure. The novel approach entails

adding two doped layers sandwiched between the neat hole-transporting layer (NPB) and the electron-

transporting/light-emitting layer (Alq3). We have used two figures of merit to evaluate these devices, the

current at 10 V (I10) and turn-on voltage defined as the voltage to produce a significant current of 0.1

mA (V0.1) just beyond the baseline so that a good signal-to-noise ratio is ascertained. Device data surmise

that the double-doped devices exhibit 57% higher luminance current and 34% lower turn-on voltage

versus the neat undoped standard devices. There are three possible reasons behind this significant

finding:

a) The interface is smoothed between the two neat (undoped) layers of pure NPB and pure Alq3.

b) The carrier injection barrier is reduced in the double-doped device.

c) Broadening of the light-emitting interface or recombination zone.

As a consequence of the phenomena above, electrons and holes will have better abilities to surpass the

neat layers in the double-doped devices, offering broader light-emitting recombination zone versus

undoped bilayer devices.





Property-Driven Synthesis: The Relationship Between Structure and Properties of Ln2Fe4-xCoxSb5 (Ln = La – Pr; x < 1.5

Katherine A. Benavides, Joseph V. Burnett, Sheng Li, Bing Lv, Julia Y. Chan*



Category: Graduate


Single crystals of Ln2Fe4-xCoxSb5 (Ln = La – Pr; x < 1.5) were grown by the flux growth technique. The

structure is comprised of Ln-capped square nets of antimony and a triangular network of transition

metals. The electrical resistivities as a function of temperature are highly dependent on Co

concentration. In this presentation, the synthesis and structure of Ln2Fe4- xCoxSb5 will be compared

to other ternary antimonides and the electrical properties of Ln2Fe4-xCoxSb5 will be discussed.





Improved Hydrogen Separation Performance of Mixed-Matrix Membranes based on Blend of Immiscible Polymers

Do Nguyen, Nimanka Panapitiya, Inga H.Musselman, Kenneth J. Balkus, John P. Ferraris*



Category: Graduate


Mixed-matrix membranes (MMMs) has showed to be one of the best strategies to improve gas

separation properties of polymeric membranes. In this work, we proposed the use of immiscible blends

of high performance polymers to serve as the matrices for MMMs. Inherent macroscopic phase-

separation of immiscible polymer blends was strategically controlled with the incorporation of

nanoparticles ZIFs, a subclass of metal-organic frameworks (MOFs). Thorough characterization of the

MMMs was carried out to ratify the proposed proposition. In term of morphology control, the domain

sizes of the dispersed phases significantly decreased and became more uniform upon increase addition

of nanoparticles ZIFs from 0% to 20%. Promising gas separation properties were achieved with the

MMM composed of 20% nanoparticles ZIFs for H2/CO2, H2/N2, and CO2/CH4 gas pairs. Binary gas-

mixture separation performance will also be discussed.




Section 3

Inorganic/Materials Chemistry 1B Sid W. Richardson Physical Sciences Building: Lecture Hall 2


08:45-09:00 Alexander T. Brown University of Texas at Dallas

Synthesis and Stabilization of new intermetallic compounds Ln52Fe2Sn49 (Ln = Y, Gd, Tb, Dy)

09:00-09:15 Kortney M. Melancon University of North Texas

New Bond on the Rise: Ligand-Unassisted d10-d10 Bonding in Heterometallic Complexes

09:15-09:30 Tharun T. Ponduru University of Texas at Arlington

Selective catalytic functionalization of aromatic C(sp2)-H bonds

09:30-09:45 Brian L Kamras University of North Texas

Lecithin Liposome-Stabilized Gold Nanorods – A Multifunctional Platform for Targeted Treatment of Diseases

09:45-10:00 P. Sotelo University of Texas at Arlington

Exploratory Synthesis of Rare Earth Sulfides as Pigments

10:00-10:15 Joshua F. Ivy University of North Texas

Metal-Inorganic Frameworks (MIFs) from Phosphorescent Platinum Building Blocks

10:15-10:30 P.B Jayathilaka University of Texas at Dallas

Synthesis of smaller mesoporous silica nanoparticles to facilitate lymph node targeted drug delivery

Inorganic/Materials Chemistry 1B Sid. Richardson Lecture Hall 2



Synthesis and Stabilization of new intermetallic compounds Ln52Fe2Sn49

(Ln = Y, Gd, Tb, Dy)

Alexander T. Brown, Keaton G. Barron, Randall P. Kirby, Julia Y Chan*



Category: Graduate


Single crystals of the new structure type Ln52Fe2Sn49 (Ln = Gd, Tb, Dy) are grown from a self-flux method

using the Ln-Fe binary eutectic point. The compounds are grown using a reaction ratio of 12 Ln : 3 Fe :

11 Sn and annealed at 1260 °C. In ambient conditions, the surface is silver with a metallic luster for the

first 12 h., then a passivation layer forms on the crystal surface. The crystal structures as determined

at 100 K were solved by the intrinsic phasing method. The Dy51.7Fe2Sn48.6 crystal structure is modeled in

space group Fmmm with lattice parameters a = 16.2992(6) Å, b = 16.9088(6) Å, c = 39.0656(14) Å,

V = 10766.5(7) Å3 with Z = 4. Ln52Fe2Sn49 has a large cell volume, structural complexity, and consists

of ten Ln, two Fe, and fourteen Sn unique crystallographic sites.





New Bond on the Rise: Ligand-Unassisted d10-d10 Bonding in

Heterometallic Complexes

Kortney M. Melancon, Mohammad A. Omary*



Category: Graduate


Where intramolecular d10-d10 interactions in hetero- and homometallic structures have been extensively

studied, our work is focused on efforts to revisit and expand on metal-metal bonding in complexes of the

form MM’(MTP)2 and MM’(dppm)n (where M/M’=Cu/Au or Ag/Au and MTP=

diphenylmethylenethiophosphinate) and MM’(dppm)n (where M/M’=Ni/Pd, Pt/Pd, or Pd/Ni and n= 2

or 3 and dppm= bis(diphenylphosphinomethane). All complexes were modeled using density functional

theory to determine if heterobimetallic d10-d10 interactions are involved. Optimized geometric structures

were examined to determine metal-metal distances. Dunham analysis was performed on the potential

well to determine metal-metal vibrational frequencies in addition to molecular orbital modeling to

determine bond order. It was found that PtNi(dppm)2 and PdNi(dppm)2 give theoretical bond orders of

zero, whereas PtPd(dppm)n, PtNi(dppm)3, PdNi(dppm)3, AuAg(MTP)2, and AuCu(MTP)2 give non-zero bond

orders. This investigation serves as a comprehensive study of new metal-metal bonds discovered in the

complexes discussed above and our efforts to develop new synthetic routes to achieve these [MM’(μ-

L)n]m d10 structures.





Selective catalytic functionalization of aromatic C(sp2)-H bonds

Tharun T. Ponduru, H.V. Rasika Dias*

Department of Chemistry and Biochemistry, University of Texas at Arlington,


Category: Graduate


The selective activation of unactivated aryl C(sp2)-H bonds is one of the most important challenging

processes in both academia and industry. There are several methods for this C-H bond activation,

among these selective and catalytic oxidation routes are particularly sought after because they

provide the simplest way to produce many industrially valuable chemicals from readily available

constituents of petroleum feedstocks. Indeed, a number of very important industrial processes are

currently in operation for this purpose. However, these processes often require harsh conditions,

strong acids and suffer from low selectivity usually due to over-oxidation. Thus, there is clearly a need

for a more efficient, milder, and environmentally friendly methodology. In our research, we would like

to investigate these processes using Copper adducts of fluorinated triazapentadiene ligands

[TAPxCu(NCMe)] as catalysts because they can last longer and tolerate highly oxidizing conditions.

We have found that these complexes catalyze the oxidation of benzene into phenol selectively using

0.5% catalyst loadings and for the conversion of anthracene into anthraquinone (87% isolated yield)

using 4% catalyst loadings. Particularly, our system does not require any acidic medium and

operates under mild conditions. Studies to ascertain the mechanism that governs these

transformations is currently underway in our laboratory.





Lecithin Liposome-Stabilized Gold Nanorods – A Multifunctional

Platform for Targeted Treatment of Diseases

Brian L Kamras, Sreekar Marpu, Mohammad A. Omary*



Category: Graduate


Gold Nanorods are intensely studied for their numerous diagnostic, imaging and therapeutic

applications. However, a critical failing of commercially produced gold nanorods is their universal

cytotoxicity due to the use of the stabilizer cetyltrimethylammonium bromide (CTAB). High quality gold

nanoparticles (dia. ~9 nm, D = 0.343, A = 517 nm) have been formed by controlled decomposition of a

Au(I) complex in the presence of crude soy lecithin, which were added to a growth solution of the very

same Au(I) complex in addition to potassium bromide and a reducer. This resulted in the formation of

lecithin-stabilized gold nanorods with longitudinal surface plasmon resonances finely tunable from 690

nm to 860 nm. Additionally, the liposomal lumen can be actively loaded with a range of materials (small

molecules, proteins, DNA, etc.) The particles were stable for approximately three weeks at room

temperature. Currently, the cytotoxicity and photothermal activity of these nanoparticles towards model

human cell lines are being investigated.





Exploratory Synthesis of Rare Earth Sulfides as Pigments

P. Sotelo, M. Orr, R. T. Macaluso*



Category: Graduate


Cadmium sulfoselenide and compounds such as lead molybdate are currently among the most widely

used pigments of this kind.1 These compounds have excellent performance characteristics, but their

toxicity is environmentally undesirable. Rare-earth sulfides and related compounds have been proposed

as promising candidates2-4, however, their syntheses involve the flow of toxic and corrosive gases and

long, complicated heating procedures5. Here, we explore the synthesis, structure and optical properties

of ALn2S4 (A = Ca, Sr, Ba; Ln = La, Ce, Pr) as alternative inorganic pigments. Our synthesis strategies

are simpler and eliminate the flow of any gases. In addition, we have optimized our synthetic strategies

based on polymorph of the starting materials. Laboratory and synchrotron X-ray diffraction, along with

scanning electron microscopy, have been used to correctly identify the phases and crystal structures of

these materials. Diffuse reflectance spectroscopy experiments have been performed to characterize

optical properties. Differential scanning calorimetry shows that ALn2S4 (A = Ca, Sr, Ba; Ln = La, Ce, Pr)

are stable up to ~5oo°C, which means that these materials may be potentially useful in widespread

plastic and paint applications.

This work has been supported by the American Chemical Society Petroleum Research Fund

Grant #52309-ND10 and the National Science Foundation CAREER Award #1541230.

References:

1. Maestro, P.; Huguenin, D., Industrial applications of rare-earths - which way for the end of the century. Journal of Alloys and Compounds 1995, 225 (1-2), 520-528. 2. Urones-Garrote, E.; Martinez, F. F.; Landa-Canovas, A. R.; Otero-Diaz, L. C., New inorganic pigments in the Ca-Nd-S system: Stabilization of gamma phase. Journal of Alloys and Compounds 2006, 418 (1-2), 86-89. 3. Perrin, M. A.; Wimmer, E., Color of pure and alkali-doped cerium sulfide: A local-density-functional study. Physical Review B 1996, 54 (4), 2428-2435. 4. Hernandez-Alonso, M. D.; Gomez-Herrero, A.; Landa-Canovas, A.; Duran, A.; Fernandez-Martinez, F.; Otero-Diaz, L. C., New ecological pigments in the Ca-Yb-S system. Journal of Alloys and Compounds 2001, 323, 297-302. 5. Flahaut, J.; Guittard, M.; Patrie, M.; Pardo, M. P.; Golabi, S. M.; Domange, L., phases cubiques type Th3P4 dans les sulfures les seleniures et les tellurures L2X3 et L3X4 des terres rares et dans leurs combinaisons ML2X4 avec les sulfures et seleniures mx de calcium strontium et baryum . Formation et proprietes cristallines. Acta Crystallographica 1965, 19, 14-&.





Metal-Inorganic Frameworks (MIFs) from Phosphorescent Platinum

Building Blocks

Joshua F. Ivy, Mohammad A. Omary*



Category: Graduate


Pt-based Inorganic building blocks were used to generate a new series of extended solids. Two series of

complexes, one based on previously-studied Pt-POP ([Pt2(P2O5)4]-4) and the other based on new metal-

carboxylate ligands have been synthesized. These materials belong to a new class of metal-inorganic

frameworks (MIFsTM) that have been designed for the purposes of functional applications such as gas

adsorption and storage, catalysis, and optoelectronics (U.S. Provisional Patent Application

62/332,292). Materials were analyzed by X-ray diffraction, low-pressure nitrogen adsorption

isotherms, UV-Vis diffuse reflectance, and photoluminescence spectroscopy. Each MIF was contrasted

with its precursor complex to determine changes in photoluminescence properties upon complexation

with additional metals. Zr(IV) and Zn(II)-based MIFs of Pt-POP showed enhanced luminescence properties

and drastically enhanced environmental stability compared to the solid starting material with non-

coordinating counterions. The zirconium-Pt-POP complex showed moderate porosity.





Synthesis of smaller mesoporous silica nanoparticles to facilitate

lymph node targeted drug delivery

P.B Jayathilaka, Kenneth J. Balkus Jr.*

Department of Chemistry, The University of Texas at Dallas,


Category: Graduate


Lymph nodes are one of the main targets of many cancer vaccines as antigens are captured by dendritic

cells in lymph nodes and initiate cellular immune responses. Various studies have been carried out to

develop nanoparticles to encapsulate antigens to protect them from the degradation and extend contact

time with the immune system. It also helps to improve their delivery to dendritic cells and lymph nodes.

However, the uptake of nanoparticles into lymph nodes depends on their particle size. Smaller

nanoparticles (size 10 and 100 nm) are more preferred and efficient than large size nanoparticles for

targeting lymphatic nodes. Therefore, this study was focus to develop smaller mesoporous silica

nanoparticles (MSp) to facilitate lymph node targeted drug delivery. MSp were synthesized by using soft

template method and the resulted particles were within the size ranging from 35 nm to 50 nm. They

were characterized with transmission electron microscope (TEM), scanning electron microscope (SEM)

and the N2 sorption isotherm and Barrett-Joyner-Halenda (BJH) pore size distribution measurements.




Section 3



11:00 -11:15 Daniel Korir University of North Texas

Facile Photochemical Synthesis and Properties of conjoined gold-silver Nanoparticles with tunable Plasmonic absorption

11:15-11:30 Hannah Johnston Texas Christian University

Synthesis and characterization of novel manganese monomers and dimers with tetraazamacrocyclic ligands

11:30-11:45 Ruaa Almotawa University of North Texas

Synthesis and Characterization of Cu(I) and Ag(I) Complexes with Mixed Diphosphine and Diimine Ligands

11:45-12:00 Jonathan Buford University of Texas at Dallas

TiO2 Nanotubes Decorated with Ruthenium-based Nanoparticles

12:00-12:15 Christopher Williams University of North Texas

Novel Ambipolar Organic Fluorophores: A Computational/Experimental Investigation of Photophysical, Redox, and Conductive Properties

12:15-12:30 Kenneth J. MacKenzie Texas A&M University – Commerce

Investigation of Palladium Catalysts, for a Green Chemistry Approach to the Selective Hydrogenation of Diphenylacetylene




Facile Photochemical Synthesis and Properties of conjoined gold-silver

Nanoparticles with tunable Plasmonic absorption

Daniel Korir, Sreekar Marpu, Mohammad A. Omary*



Category: Graduate


Plasmonic metal nanoparticles have been extensively studied for their unique optical properties arising

due to Localized Surface Plasmon resonance (LSPR). Especially, gold and silver nanoparticles with

tunable Surface Plasmon Resonances (SPR) have been studied for applications including Photo Thermal

Therapy (PTT), drug delivery, antimicrobial/ antipathogenic and sensor applications. This study overviews

the synthesis and surface enhanced Raman spectroscopy (SERS) of bifunctional conjoined gold- silver

nanoparticles (Ag-Au) different from well-established alloyed or core shell structures reported in the

literature. In this effort, we synthesized bimetallic nanomaterials within biocompatible

stabilizers/matrices following facile photochemical technique. Conjoined Ag-Au NPs retaining plasmonic

absorption of both metals are achieved using varied aspect ratios of gold seeds followed by careful

growth of silver as Nano-twin feed under similar photochemical conditions. The bimetallic nanoparticles

with tunable SPR are expected to exhibit synergetic properties of gold and silver beneficial for both

materials and biomedical applications.





Synthesis and characterization of novel manganese monomers and

dimers with tetraazamacrocyclic ligands

Hannah Johnston, Kayla N. Green*



Category: Graduate


Manganese containing enzymes are prevalent in nature; one specific example is the oxygen

evolving complex (OEC) located in photosystem II (PSII) of green plants. Due to the biological

relevance of manganese, model complexes with this transition metal are ubiquitous in the

chemical literature, particularly those modeling the OEC in PSII. Historically, OEC models

incorporate two multidentate nitrogen contain ligands coordinated to Mn(III) and Mn(IV)

connected by two bridging oxygens. Although rudimentary models, these bimetallic complexes

have shown the ability to perform several catalytic reactions. Recently, we have metalated

pyridine- and pyridol- containing macrocycles with manganese to form both the historically

significant Mn(III,IV) dimer complex as well as a Mn(III) monomer. A Mn(III,IV) dimer with a pyridol-

containing macrocyclic is the first of its kind synthesized to date. Characterization of both the

monomeric and dimeric manganese complexes, as it relates to the OEC includes: UV-Visible

spectroscopy, X-ray diffraction (XRD), cyclic voltammetry (CV), and electron paramagnetic

resonance (EPR). In the future, the catalytic activity of these complexes will be investigated.





Synthesis and Characterization of Cu(I) and Ag(I) Complexes with

Mixed Diphosphine and Diimine Ligands

Ruaa Almotawa,a,b Kimberly Savage,a Fatemah Behnia,a Manal A. Rawashdeh-Omary,b,* Mohammad A.

Omary a ,*

a Department of Chemistry, University of North Texas

b Department of Chemistry and Biochemistry, Texas Woman’s University


Category: Graduate


A series of copper(I)/silver(I) ionic complexes containing bis[2-diphenylphosphino)phenyl]ether and

diimine ligands, including (pyrazine, 4’4-dipyridyl (bpy), 1,2-bis(4-pyridyl) ethylene (bpe), 4,4′-

trimethylenedipyridine (bpp), 1,2-bis(4-pyridyl)ethane (bpa), and 4’4-azopyridine (azopy)), and BF4 as an

anion has been synthesized. The complexes were characterized by X-ray diffraction, IR, luminescence,

NMR spectroscopy and thermal gravimetric analysis (TGA). The goal of this project is to provide novel

compounds that can be utilized in electronic and photonic materials. The chemistry of silver (I) and

copper (I) ions with N^N as a diimine ligand and P^P as a diphosphine ligand exhibits promising emissive

species. They are emerging as promising candidates for highly efficient emitters in organic light emitting

diodes (OLEDs).





TiO2 Nanotubes Decorated with Ruthenium-based Nanoparticles

Jonathan Buford, Kenneth J. Balkus*



Category: Graduate


This research focuses on depositing ruthenium-based nanoparticles on the surface of TiO2 nanotubes,

with the intention of using these synthesized materials for photocatalysis. The inspiration for this project

stemmed from an interest in predicting the band gap of the TiO2 nanotubes (3.0eV-3.2eV) after the band

was bent by the ruthenium material.

These TiO2 nanotubes are formed via a hydrothermal synthesis, while the ruthenium is introduced in the

form of the salt RuCl3∙nH2O. The Ruthenium ions are bound to the nanotubes using thiolactic acid (TLA)

as a linker. The concentration of linker in solution also helps to regulate the sizes of the ruthenium-based

nanoparticles that are bound to the surface. Ruthenium nanoparticle attachment is accomplished with

use NaOH or Na2S to yield RuO2 or RuS2 nanoparticles respectively.

The synthesized TiO2 nanotubes with ruthenium-based nanoparticles are imaged with transmission

electron microscopy and the crystalline structure is displayed via X-ray diffraction. In conclusion the TiO2

nanotubes decorated with ruthenium-based nanoparticles were formed and the research in the future

will consist of changing the TLA concentration to adjust size and eventually use the for photocatalytic

purposes.





Novel Ambipolar Organic Fluorophores: A

Computational/Experimental Investigation of Photophysical, Redox,

and Conductive Properties

Christopher Williams, Gustavo Salazar, Mohammad A. Omary*



Category: Graduate


The photophysical properties of metal complexes with heterocyclic aromatic ligands have sparked great

interests in applications that range from solar energy conversion to LED phosphors. However, typical

heterocyclic aromatic ligands (e.g., bipyridine/phenanthroline/terpyridine) exhibit low extinction

coefficients, too-high absorption energies (mid-UV), and unipolar (n-type) charge transport

characteristics, all of which negatively impact their/their derivative’s use in optoelectronic devices.

Herein, UV-vis and photoluminescence properties are investigated for novel ambipolar organic

molecules/ligands containing an electron-rich N,N-diethylphenylamine group and an electron-poor

triazine core that bears two other N-donor azole (Az) substituents. This molecular design allows fine-

tuning the HOMO-LUMO energy through modifying the steric and/or electronic factors upon Az group

variation. TD-DFT calculations with M06 and B3LYP functionals were performed and attained excellent

qualitative agreement with experimental results. Analysis of frontier molecular orbitals and electron-

density distribution vs Az substituents was also implemented. Solvent effects on the photophysical

properties of these compounds will be presented for both the fluorophores per se and their adducts

with Re(I), taken as the first case study for metal complexes. Both computations and experiments

underscored the superiority of the novel molecules in terms of overcoming ALL aforementioned

limitations of conventional polyimine counterparts.





Investigation of Palladium Catalysts, for a Green Chemistry Approach

to the Selective Hydrogenation of Diphenylacetylene

Kenneth J. MacKenzie, Jessica Velazquez, Syed S. A. Hussaini, Dr. Bukuo Ni, Dr. Ben Jang*

Department of Chemistry, Texas A&M University – Commerce


Category: Graduate


There has been a growing interest in catalyzed hydrogenation, as a means of chemical synthesis in the

pharmaceutical, petrochemical, and food industries. These industries use metal based catalysts as a

means of mass producing common chemical products (such as fats and oils, vitamin A, and polymeric

monomers). Using heterogeneous catalysts, alkynes can be selectively reduced to alkenes and not to

alkanes. With this research, we hope to analyze the conversion, and selectivity potentials of an array of

palladium catalysts in the hydrogenation of diphenylacetylene. We hypothesize that these catalysts can

be used to hydrogenate close to 100% of the substrate, to the cis- and trans- stilbene, without producing

significant amount of bibenzyl. The results show that high conversion and relatively low selectivity or high

selectivity and relatively low conversion can be obtained with the catalyst of 0.05%Pd supported on

alumina. This area of chemical synthesis, would allow industry to further employ the values of green

chemistry, by using recoverable catalysts, with close to 100% conversion and selectivity towards the

production of the desired product. This method of synthesis would lessen the production of wasteful

byproducts, minimize solvent use, and reduce reaction times.




Section 3



01:30 -01:45 Khaled Shennara University of North Texas

PPTT: Treating Cancer Cells

01:45-02:00 Mohammed Irfan Zakir Omer Texas A&M University Commerce

Mesoporous Catalysts for the Synthesis of Biodiesel

02:00-02:15 Anne D’Achille Texas Christian University

Suppression of Melanin Synthesis by Europium Doped Cerium Oxide Nanomaterials

02:15-02:30 Sinjinee Sardar University of Texas at Arlington

Kinetic and spectroscopic investigation of the catalytic triad of the non-heme mononuclear iron enzyme 3-mercaptopropionate dioxygenase from Azotobacter vinelandii (Av MDO)

02:30-02:45 Rajesh Kumar Southern Methodist University

Synthesis of Linear and Branched Polymers Utilizing Hypervalent iodine Compound




PPTT: Treating Cancer Cells

Khaled Shennara, Mohammad A. Omary*



Category: Graduate


Photothermal therapy is a rising promise for treating different cancer cells. However, there are side

effects from this therapy, and thus our team is interested in technique development of PPTT using

metallic nanoparticles. The PPTT protocol will be developed upon a modification of the irradiation therapy

using two major changes. The first is using a less harmful visible light or a harmless near infrared light,

and the second is using gold-loaded biocompatible nanoparticles. Acrylate nanoparticles will be loaded

with desired types of gold nanoparticles at different sizes. The gold-loaded gold nanoparticles will be

conjugated to cancer cells. By selectively delivering the gold nanoparticles into cancer cells, irradiating a

harmless near infrared light will achieve a thermal ablation of the cancer cells. Based on imaging

spectroscopy and flow cytometry, results showed reduction of gold loaded-normal cancer cells upon

irradiating with a near infrared light, and no change in the number of cancer cells with irradiating with

light only.





Mesoporous Catalysts for the Synthesis of Biodiesel

Mohammed Irfan Zakir Omer , Syed Shah Abdullah Hussaini and Syed Zia, Dr. Ben Jang*



Category: Graduate

Division: General Chemistry

Depletion of fossil fuel has been a big threat to humans along with environmental pollution, the interest

to create and use plant oils and animal fats as biodiesel has been constrained up to these years and

now has been put into use. In this paper starch is investigated as the precursor to synthesize various

mesoporous catalysts with pore size 2 – 50 nm, for the esterification of oleic acid with methanol as the

probe reaction for the production of biodiesel. The results show that the activity of mesoporous catalysts

is a function of surface properties such as surface areas, porosity, acid density, etc. and the functional

groups attached to the structure can be depicted by Fourier Transform Infrared Spectroscopy, acid-

base titration and Nuclear Magnetic Resonance Spectroscopy It is concluded that careful attention is

needed during each stage of catalyst preparation, such as gelatinization, retrogradation, exchange,

drying, and sulphonation, to result in catalysts with high acid density values for the production of biodiesel.





Suppression of Melanin Synthesis by Europium Doped Cerium Oxide

Nanomaterials

Anne D’Achille, Jeffery Coffer*



Category: Graduate


Nanomaterials based on cerium (IV) oxide, CeO2, have been investigated due to interesting chemistry

from a readily available transition between Ce3+ and Ce4+. This transition, along with oxygen vacancies

present in the oxide lattice, give CeO2 materials antioxidant and enzyme mimetic behavior.i Doping with

trivalent, fluorescent ions such as Eu3+ further increases the oxygen vacancy concentration, controls the

Ce3+/Ce4+ ratio, and may add fluorescence to the doped material.ii

Eumelanin is a complex dark brown pigment originating from the oxidation and oligimerization of tyrosine

or through the auto-oxidation of L-3,4-dihydroxyphenylalanine (L-DOPA). The pigment’s antioxidant

activity, strong UV-VIS absorption, and conductive properties give it potential applications in radiation

damage protection, and treatment of Parkinson’s and Alzheimer’s disease.iii

Our research thus far has focused on the controlled synthesis of various EuCeO2 materials, and their

interaction with the auto-oxidation of L-DOPA to eumelanin. EuCeO2 nanorods and nanocubes were

synthesized through a hydrothermal reaction of precipitated EuCe(OH)3. Nanowires were synthesized

using electrospinning and annealing techniques.

The presence of CeO2 or EuCeO2 materials consistently suppressed the eumelanin-associated

fluorescence intensity. Temperature, pH, nanomaterial concentration/morphology, and europium

dopant concentration were all evaluated for potential impact on the evolution of eumelanin from L-DOPA

in the presence of EuCeO2 nanomaterials.

References

i Xu, C.; Qu, X. NPG Asia Materials, 2014, 6, 1-16 ii Kumar, A.; Babu, S.; Karakoti, A.S.; Schulte, A.; Seal, S. Langmui,r 2009, 25(18), 10998–11007 iii Sutter, J. ; Birch, D. Methods Appl. Fluoresc. 2014, 2, 024005





Kinetic and spectroscopic investigation of the catalytic triad of the non-

heme mononuclear iron enzyme 3-mercaptopropionate dioxygenase

from Azotobacter vinelandii (Av MDO)

Sinjinee Sardar, Andrew Weitz, Michael Hendrich and Brad S. Pierce


Department of Chemistry, Carnegie Mellon University Pittsburg


Category: Graduate


3-mercaptopropionate dioxygenase from Azotobacter vinelandii (Av MDO) is a non-heme mononuclear

iron enzyme that catalyzes the O2-dependent oxidation of 3-mercaptopropionate (3mpa) to form 3-

sulfinopropionic acid (3spa). Within the MDO active site three outer sphere Fe-coordination residues

S155, H157 and Y159 is observed. This “catalytic triad” is universally conserved among all known thiol

dioxygenase enzymes across the phylogenic domain but their role in catalysis is yet to be understood. In

this work, the pH-dependent steady state kinetics for wild-type MDO and selected variants (H157N and

Y159F) are compared. Taken together with supporting EPR and Mössbauer spectroscopic studies, a

mechanistic model is proposed in which the ‘catalytic triad’ serves gate proton delivery to the substrate-

bound Fe-site.





Synthesis of Linear and Branched Polymers Utilizing Hypervalent iodine Compound

Rajesh Kumar, Nicolay V. Tsarevsky*



Category: Graduate


A method for the preparation of chlorine-containing linear and branched polymers was developed in the

presence of 1-chloro-1, 2-benziodoxol-3(1H)-one (ClBIO), which served both as an initiator and a transfer

agent. ClBIO is a heterocyclic hypervalent iodine (III) compound with a labile I-Cl bond, which can be easily

cleaved homolytically upon heating or irradiation with visible or UV light. The reactive chlorine radicals

initiated the polymerization of methyl methacrylate at 80°C, yielding polymers with an Cl functionality at

the ɑ-terminus. Fast termination by coupling of the propagating radicals with Cl radicals and possibly Cl

transfer from ClBIO were responsible for the formation of low-molecular weight linear polymers with an

Cl group at the ɯ-end. When the polymerizations were carried out in the presence of divinyl compounds

(crosslinkers), highly branched polymers were produced prior to gelation. The network formation was

delayed in these systems until moderate to high monomer conversions were reached due to the

aforementioned termination and/or transfer, which limited the size of the interconnected chains and

therefore the average number of incorporated pendant vinyl groups per chain. The use of the ClBIO

initiating system proved to be an efficient one-pot route to mono- and dichlorine-capped linear or multi-

chlorinated branched polymers that could be easily further functionalized in future.




Section 4

Organic/Analytical Chemistry 1 Sid W. Richardson Physical Sciences Building: Lecture Hall 4


08:45-09:00 Jacob W. McCabe Texas A&M University – Commerce

Investigation of the Selected Transition Metal Binding Characteristics of Methanobactin from Methylosinus trichosporium OB3b

09:00-09:15 Taniya M.S.K. Pathiranage University of Texas at Dallas

Enhanced supramolecular self-assembly of P3HT by block copolymer synthesis

09:15-09:30 Parham Asgari University of Texas at Arlington

Catalytic Reductive ortho-C–H Silylation of Phenols with Traceless, Versatile Acetal Directing Groups and Synthetic Applications of Dioxasilines

09:30-09:45 Swetha Chinthala Texas A&M University – Commerce

Zn(II) And Cu(I/II) Co-Ordination to Alternative Metal Binding Peptide Using Ion Mobility - Mass Spectrometry and Fluorescence Spectroscopy Techniques

09:45-10:00 Yi Hu University of North Texas

β-Functionalized Push-Pull Dibenzoporphyrin

as Light Harvester for Dye-Sensitized Solar Cell

10:00-10:15 Shivaraj Yellappa University of North Texas

Phenothiazine sensitized photovoltaic cells: effect of co-adsorbant on cell performance

10:15-10:30 Enrique Barragan University of Texas at Arlington

Triazenes: Intermediates that Undergo Oxidation and Substitution Reactions

Organic/Analytical Chemistry 1 Sid. Richardson Lecture Hall 4



Investigation of the Selected Transition Metal Binding Characteristics of Methanobactin from Methylosinus trichosporium OB3b

Jacob W. McCabe, Rajpal Vangala, Laurence A. Angel*



Category: Graduate


The methanobactin (Mb) from Methylosinus trichosporium OB3b (1154.26 Da) is a member of a class

of metal binding peptides identified in methanotrophic bacteria. Methanobactins will selectively bind and

reduce Cu(II) to Cu(I), and mediate the acquisition of the copper cofactor for the enzyme methane

monooxygenase. Methanobactins will also bind other metal ions and mediate their solubilization and

transportation in situ. The structure of Mb consists of nine amino acids and two modified regions

containing enethiol-oxazolone rings which are the bidentate binding sites for Cu(I). However, the binding

characteristics for Ag(I), Pb(II), Co(II), Fe(III), Mn(II), Ni(II), and Zn(II) have not been determined. The goal of

this study is to compare the binding of these metals to the [Mb+Cu(I)-nH](n-1)− complex using traveling

wave ion mobility mass spectrometry (TWIMS). The arrival time distribution (ATD) for each metal

complex and free mb-OB3b was used to quantify the apparent binding affinity and measure their collision

cross-section at various pH points. In addition, collision-induced dissociation of the disulfide reduced

[Mb+M], was used to locate the binding sites of the individual metal(I/II) ions (M), and the normalized

collision energy, breakdown curve was measured to determine the relative stability of the disulfide

reduced [Mb+M] complexes. Selected mass spectrometry titration studies were repeated using

fluorescence spectroscopy to compare gas-phase and solution-phase techniques.





Enhanced supramolecular self-assembly of P3HT by block copolymer synthesis

Taniya M.S.K. Pathiranage, Michael C. Biewer and Mihaela C. Stefan*



Category: Graduate

Division: Organic/Polymer Chemistry

A diblock copolymer of poly(3-hexylthiophene) (P3HT) and methacrylates with pyrene side chains was

synthesized by Grignard metathesis polymerization (GRIM) and Initiators for Continuous Activator

Regeneration Atom Transfer Radical Polymerization (ICAR-ATRP). With ICAR-ATRP we could have

reduced the amount of copper used up to 90% compared to conventional ATRP while assuring good

incorporation of the second block maintaining narrow PDI. Pyrene, a thermotropic liquid crystalline

mesogen, was incorporated into P3HT. The composition of synthesized copolymer was determined by

1H-NMR analysis. Improved long-range ordering of polymer with unique morphological features was

observed in TMAFM images. Characterization of the thermotropic liquid crystalline behavior was

performed in a combined study with polarizing optical microscopy with heating stage and DSC. The liquid

crystalline mesophases of the copolymer appeared above the glass transition of P3HT which helps to

trigger long-range ordering of P3HT by co-crystallization after annealing above thermotropic mesophase

transitions. The effect of annealing on self-assembly and morphological changes of the block copolymer

was studied with tapping mode atomic force microscopy (TMAFM), thin film X-ray diffraction (XRD), and

UV-VIS analysis. The field effect mobility of the P3HT diblock copolymer was determined in organic field

effect transistors (OFET); Hole mobility as high as 10-2 cm2/Vs were measured.





Catalytic Reductive ortho-C–H Silylation of Phenols with Traceless, Versatile Acetal Directing Groups and Synthetic Applications of

Dioxasilines

Parham Asgari, Yuanda Hua, Thirupataiah Avullala, Junha Jeon*



Category: Graduate


A new, highly selective, bond functionalization strategy, achieved via relay of two transition metal catalysts

and use of traceless acetal directing groups, has been employed to provide facile formation of C–Si

bonds, and concomitant functionalization of a silicon group, in a single vessel. Specifically, this approach

involves the Ir-catalyzed hydrosilylation of inexpensive and readily available phenyl acetates, exploiting

disubstituted silyl synthons, to afford silyl acetals and Rh-catalyzed ortho-C–H silylation to provide

dioxasilines. A subsequent nucleophilic addition to silicon efficiently re-moves the acetal directing groups

and directly provides unmasked phenol products and, thus, useful functional groups at silicon achieved

in a single vessel. This traceless acetal directing group strategy for catalytic ortho-C–H silylation of

phenols was also successfully applied to preparation of multi-substituted arenes. Remarkably, a new,

formal -chloroacetyl directing group has been developed which allows catalytic reductive C–H silylation

of sterically hindered phenols. In particular, this new method permits to access to highly versatile and

nicely differentiated 1,2,3-trisubstiuted arenes that are difficult to ac-cess by other catalytic routes. We

demonstrated multiple synthetic potential of this strategy, such as aryne chemistry, Au-catalyzed direct

and sequential orthogonal cross-couplings, late-stage silylation of phenolic bioactive molecules, and

BINOL scaffolds.





Zn(II) And Cu(I/II) Co-Ordination to Alternative Metal Binding Peptide Using Ion Mobility - Mass Spectrometry and Fluorescence

Spectroscopy Techniques

Swetha Chinthala, Laurence A. Angel, PhD*



Category: Graduate


Methanotrophic bacteria are the prokaryotic organisms that oxidize methane to produce a small copper

chelating molecule called methanobactin (Mb) and are unique in their ability to utilize methane as sole

source of energy. The methanobactins produced by Methylosinus trichosporium (mb-OB3b), currently

characterized as modified chromopetides that bind to Cu(I) and other metals with high affinity, are

assumed to mediate copper acquisition from the environment for particulate methane monooxygenase

(pMMO) enzyme. Current research involves study of Cu(I/II) and Zn(II) binding to alternative metal binding

peptide with sequence CH3CO-His1-Cys2-Gly3-Pro4-Tyr5-His6-Cys7-NH2 (amb5B, MW-856.99 Da) as a function of

pH and Zn(II), Cu(I/II) concentration using fluorescence and ion mobility- mass spectrometry techniques.

Structural importance of disulfide linkage and metal binding profile of analog methanobactin will be studied.

Collision induced dissociation (CID) experiments will be conducted to induce fragmentation of peptide ions

in gas phase using mass spectrometry. A binding profile of the analog methanobactin with metal ions like

Zn (II) and Cu (I/II) will be developed in comparison to fluorescence spectroscopy.





β-Functionalized Push-Pull Dibenzoporphyrin as Light Harvester for

Dye-Sensitized Solar Cell

Yi Hu, Shivaraj Yellappa, R. G. Waruna Jinadasa, D’souz Francis*, and Hong Wang*

Chemistry Department, University of North Texas,


Category: Graduate


Dye-sensitized solar cells (DSSC) have attracted much attention as a promising alternative to

siliconbased solar cells. [1] when it comes to photosensitizing pigments, porphyrins are obvious

candidates because of their well-known role as light harvesters and charge separations in natural

photosynthetic system. [2] In order to utilize porphyrin as DSSC sensitizer, it is very important to rationally

modify the basic porphyrin structure to maximize the light-harvesting ability, such as introduction of a

push-pull structure and elongation of porphyrin π-conjugation. [2]

Previously, we have investigated the effect of the π-conjugated spacer on the performance of DSSCs. [3]

Based on the previous results, a series of new β-functionalized push-pull porphyrin dyes were synthesized

using heck cascade reaction and bromination chemistry. In this series, the porphyrin dye with vinylene

linker substituted dibenzoporphyrin achieved the highest power conversion efficiency of 5.9 % with

highest JSC (13.80 mA), FF (0.66) and VOC (0.65 V) values. DFT calculation demonstrated a significant

shift of LUMO towards the pull group, which would help to facilitate the electron injection from photo

excited dye to the TiO2.

[1] Li, Lu-Lin, and Eric Wei-Guang Diau, Chem. Soc. Rev., 2013, 42, 291-304

[2] Higashino, Tomohiro, and Hiroshi Imahori, Dalton Trans., 2015, 44, 448-463

[3] Jinadasa, R. G., et al., ChemSusChem, 2016, 9, 2239-2249.





Phenothiazine sensitized photovoltaic cells: effect of co-adsorbant on cell performance

Shivaraj Yellappa1,2, Whitney Webre1, Habtom B. Gobeze1, Anna Middleton1, Francis D’Souza1*

1Department of Chemistry, University of North Texas, 2Government Science College, Bengaluru -560001, Karnataka, India


Category: Graduate


In this study, the co-adsorbant molecule chenodeoxycholic acid (CDCA) have a complementary effect in

the light harvest and the performance of a phenothiazine based Dye Sensitized solar cell is reported.

CDCA is used to prevent agglomeration during the soaking process onto TiO2 surface. Absorption and

fluorescence studies were performed to characterize and observe spectral coverage of the

phenothiazine dyes, whereas electrochemical studies allowed estimation of the free energy of charge

injection. B3LYP/6-31G* studies were performed to visualize location of the Frontier orbitals and their

contribution to the charge injection when they were surface modified on TiO2. Better dye regeneration

efficiency for co-adsorbed cells compared to the cells with no co-adsorbent was revealed. The kinetics of

charge injection and charge recombination on the TiO2∕phenothiazine dyes/co-adsorbent electrodes

were analysed by Femtosecond transient absorption studies. The DSSCs were built on nanocrystalline

TiO2 using the traditional two-electrode Grätzel solar cell setup with a reference cell based on N719 for

comparison purposes.

KEYWORDS: Phenothiazine dyes, organic solar cell, co-adsorbant, photoelectrochemistry; Energy

Conversion and Storage.





Triazenes: Intermediates that Undergo Oxidation and Substitution Reactions

Enrique Barragan, Alejandro Bugarin*



Category: Graduate


Molecules able to produce a variety of different synthetic targets, so-called “versatile molecules” are a

main goal in current organic chemistry research. -conjugated triazenes derived from organic azides

and N-heterocyclic carbenes are largely unexplored species. In this work, we report novel reactivity for

-conjugated triazenes. By treating these molecules in DMSO under acidic conditions, oxidation to the

corresponding aldehyde or ketone was achieved, a development compared to common methods that

require basic conditions. Additionally, by varying the reaction conditions and utilizing different O and S

nucleophiles, the corresponding ether and sulfide substitution products were obtained. These results

demonstrate that conjugated triazenes are versatile molecules that allow the use of organic azides

as synthetic scaffolds for the synthesis of aldehydes, ketones, ethers and sulfides under mild conditions

and without addition of metal catalysts.




Section 4



11:00 -11:15 Nimmy Mammoottil University of Texas at Dallas

Surface Re-organization and Vapor Sensitivity of PNOC

11:15-11:30 Thirupataiah Avullala University of Texas at Arlington

Hydrogenative and Dehydrogenative C–C -bond silylation via a traceless directing group approach using silyl acetals

11:30-11:45 Stephen M. Budy Southern Methodist University

Microwave-assisted polyarylene: Synthesis, characterization, and optimization

11:45-12:00 Gayan A. Appuhamillage University of Texas at Dallas

3D Printable Diels-Alder Polymers as Electrical Insulating Materials

12:00-12:15 Shuai Shao University of North Texas

Self-assembled supramolecular BODIPY derived donor-acceptor systems for electron transfer

12:15-12:30 Luke Ryan Southern Methodist University

Synthesis and Characterization of Photocaged Cheiluminescent Molecules




Surface Re-organization and Vapor Sensitivity of PNOC

Nimmy Mammoottil, Bruce M. Novak*



Category: Graduate


Polycarbodiimides, a class of helical macromolecules, were initially synthesized in 1994 in a living fashion.

Since then, studies on the nitrogen-rich polymer has accelerated with the discovery of the polymers’

regioregular backbone, chiroptical switching abilities, antibacterial properties and self-assembly

behaviors. Herein, poly(N-1-naphthyl-N’-octadecyl-carbodiimide) (PNOC) was synthesized and behaviors

analyzed, related to the bi-stable contraction and expansion of the helical backbone, where the sterically

bulky naphthyl group is relegated to the imine position and the octadecyl chain fixed to the amine position.

Due to PNOC’s heightened sensitivity to various organic solvents, a thin film of the polymer can be utilized

to detect miniscule differences as the film is exposed to various solvents in their vapor phase. The same

sensitivity can also be used to monitor unique surface re-organization behavior as the thin film of the

polymer experiences the contraction and expansion of the helix with the deposition of chiral solvents.

Real-time FTIR, VCD, Specific optical rotation and Goniometer studies were employed in order to quantify

the unique phenome exhibited by PNOC.





Hydrogenative and Dehydrogenative C–C -bond silylation via a

traceless directing group approach using silyl acetals

Thirupataiah Avullala, Yuanda Hua, Parham Asgari, Apparao Bokka, and Junha Jeon*



Category: Graduate


The development of highly selective C–C -bond hydrosilylation and dehydrogenative silylation of

cyclopropanes with silyl acetal directing group is described. Specifically, cyclopropane system possessing

silyl acetal directing group would effect directed C–C-bond activation/silyl insertion over proximal Csp2–H

and Csp3–H bonds. In this work, we described the relay of Ir-catalyzed hydrosilylation of inexpensive and

readily prepared cyclopropanoacetates which we prepared by Kulinkovich reaction, followed by Rh-

catalyzed hydrogenative and dehydrogenative C–C bond silylation to provide dioxasilepines and

dioxasilolanes via putative [6,4]-bicyclic fused cyclometallated intermediate. Subsequent dehydrogenative

β-hydride elimination followed by reductive elimination would furnish dioxasilepines. Alternatively, in the

presence of Rh-Tp catalyst observed hydrosilylative sequential reductive elimination to provide

dioxasilolanes. We gained mechanistic insights into the two distinctive organocmetallic pathways. We

applied the hydrogenative and dehydrogenative C–C -bond silylation method on complex bioactive

molecules such as estradiol.





Microwave-assisted polyarylene: Synthesis, characterization, and optimization

Stephen M. Budy, Xu Chang, David Y. Son*



Category: Graduate


A series of Diels–Alder polyarylene polymers were synthesized via microwave-assisted step-growth

polymerization. Optimization of 1,4-bis(2,4,5-triphenylcyclopentadienone)benzene with 1,4-

diethynylbenzene using a variety of solvents, concentration, and time was achieved. The polyarylene

polymers were characterized by 1H NMR, FTIR, TGA, DSC, DMA, and GPC. Thermal analysis showed little

change in the series of polymers for onset of decomposition (Td = 550 °C). Polar solvents (e.g.,

tetrahydrofuran and nitrobenzene) worked well for microwave-assisted polymerization, however,

nonpolar/aromatic solvents (e.g., toluene and xylene) also afforded lower molecular weight polyarylene

polymers/oligomers. Molecular weights were monitored over time affording well over 100 kg/mol and

dispersities more difficult to control in the range 1.9 to 20.1. Further work will involve scaling up the

polymerization reactions and also using a variety of different monomers.





3D Printable Diels-Alder Polymers as Electrical Insulating Materials

Gayan A. Appuhamillage, Grant Sturgeon, Ronald A. Smaldone*

Department of Chemistry & Biochemistry, University of Texas at Dallas


Category: Graduate


Electrical insulating materials are of great importance in wiring boards, ceramic packages, and

electronic components. Here we report a novel 3D printable insulating polymer series synthesized based

on furan and maleimide Diels-Alder chemistry containing polyether, amide, and ester functionalities in

the backbone. These functionalities govern the electrical insulating properties while the reversible Diels-

Alder dynamics of furan and maleimide moieties enable 3D printability of the material to the desired

geometry. Followed by the synthesis, these polymers were subjected to structural, thermal, and

electrical characterization. Thermogravimetric analysis (TGA) shows their high thermal stabilities up to

~ 400 °C while differential scanning calorimetry (DSC) results indicate the Diels-Alder reversibility via

endothermic transitions ~ 120-150 °C. Dielectric constant, dielectric strength, and current-voltage (CV)

measurements confirm their potential use as electrical insulating materials especially in capacitors as

high dielectric materials to enhance the capacitance, preventing current leakages in batteries and

flexible electronics.





Self-assembled supramolecular BODIPY derived donor-acceptor systems for electron transfer

Shuai Shao, Habtom Gobeze, Dr. Francis D’Souza*



Category: Graduate


A new series of self-assembled supramolecular donor–acceptor conjugates capable of wide-band

capture and exhibiting photoinduced charge separation have been designed, synthesized and

characterized using various techniques as artificial photosynthetic mimics. The donor host systems

comprise of a 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) containing a crown ether entity at the

meso-position and two styryl entities on the pyrrole rings. The styryl end groups also carried additional

donor (triphenylamine, phenothiazine, phenylferrocene) entities. The acceptor host system was a

fulleropyrrolidine comprised of an ethylammonium cation. Owing to the presence of extended conjugation

and multiple chromophore entities, the BODIPY host revealed absorbance and emission well into the

near-IR region covering the 300–850 nm spectral range. The donor–acceptor conjugates formed by

crown ether–alkyl ammonium cation binding of the host–guest system were characterized by optical

absorbance and emission, computational, and electrochemical techniques. Spectral evidence for the

occurrence of photoinduced charge separation in these conjugates was established from femtosecond

transient absorption studies. The measured rates indicated ultrafast charge separation and relatively

slow charge recombination revealing their usefulness in light-energy harvesting and optoelectronic

device applications.





Synthesis and Characterization of Photocaged Cheiluminescent Molecules

Luke Ryan, Alexander Lippert*



Category: Graduate


Chemiluminescent probes are popular synthetic targets due to their inherently high signal-to-noise ratio.

However, most chemiluminescent probes suffer from inadequate overall signal strength due to low

accumulation in the cell before the probes react. Photocaged molecules solve this problem by “caging”

the reactive site of the probe, allowing it to bioaccumulate in the cell. Here, we describe the synthesis of

several photocaged chemiluminescent molecules with tunable excitation and emission wavelengths to

achieve a chemical “color palette” of probes. Two such probes have been characterized, and exhibit both

high turn-on and wavelength excitation specificity.




Section 4



01:30 -01:45 Ravi P. Singh University of Texas at Arlington

Studies towards the Total Synthesis of Spirocalcaridines

01:45-02:00 Apsara K. Herath University of Texas at Arlington

Approaches Toward the Total Synthesis of Nagelamides A and C

02:00-02:15 Pawan Thapa University of Texas at Arlington

Green Synthesis of Organic Dyes by Artificial Riboflavin Mimics

02:15-02:30 Hiep Nguyen University of Texas at Arlington

3,3’-of Functionalization of BINOL

02:30-02:45 Habtom B. Gobeze University of North Texas

Efficient mimicry of photosynthetic antenna-reaction center in supramolecular assemblies featuring BODIPY-Al(TTP) axially coordinated to pyridyl appended fulleropyrrolidine.

02:45-03:00 Apparao Bokka University of Texas at Arlington

Grubbs-Type Ruthenium Complex-Catalyzed Alkene-Silane Cross-Couplings and Their Synthetic Applications




Studies towards the Total Synthesis of Spirocalcaridines

Ravi P. Singh, Carl J. Lovely*



Category: Graduate


A concise strategy towards a total synthesis of the natural products belonging to the Leucetta family of

alkaloids, spirocalcaridine A (3) and spirocalcaridine-B (4) will be described. We have developed a tandem

oxidative amination dearomatizing spirocyclization (TOADS) reaction of propargyl guanidines for the

construction of the main framework of spirocalcaridines (2) with good yields. A similar approach with

propargylic ureas resulted in the formation of 2-iminooxazoles (6) with moderate yields. We wanted to

explore the similar cyclization reaction with corresponding thioureas, but attempts to synthesize the

thioureas by reacting the propargylic amines with isothiocyanates in presence of Et3N were

unsuccessful. However, we discovered a new reaction of propargylic amines with isothiocyanates in

presence of Et3N to form 2 iminothiazoles (5) in excellent yields.





Approaches Toward the Total Synthesis of Nagelamides A and C

Apsara K. Herath, Manoj Bhandari and Carl Lovely*



Category: Graduate


Nagelamides are pyrrole-imidazole alkaloids, isolated from a marine sponge, Agelas sp. Our lab is

following a divergent strategy to synthesize several family members of these heterocyclic natural

products. Construction of scaffold A by a Stille cross-coupling reaction is the key step in the synthesis.

According to our results we found that the nitrogen atoms installation in the allylic chains is challenging

and several approaches have been utilized to introduce this feature. The current approach consists of

synthesis of allylic azides followed by acylation from thioacids and this presentation will describe this

attempt in detail.

A similar strategy can be used for the nagelamide A as well.





Green Synthesis of Organic Dyes by Artificial Riboflavin Mimics

Pawan Thapa, Frank W. Foss Jr.*



Category: Graduate


In nature, riboflavin (Vitamin B2) is known to catalyze carbon-carbon (C-C) bond forming reactions, which

generate valuable metabolites require for proper growth, development, and survival of organisms. To

perform C-C bond formation in a sustainable manner, several artificial riboflavin mimics were designed,

synthesized, and studied to perform reactions normally carried out by heavy metals, rare-earth metals,

or powerful acids. A subclass of riboflavin mimics was found to catalyze C-C bond formation by activating

small molecules in a new manner. This approach was used to synthesize various industrially important

dyes and chemical reagents. Additionally, the relationship discovered between molecular structure and

catalytic function of riboflavin mimics in these new chemical reactions revealed a plausible explanation

for the function of natural riboflavin-dependent oxynitrilase enzymes in natural system. Oxynitrilases are

poorly understood, but valuable enzymes for the synthesis of cyanohydrins, an important class of organic

compounds. Future efforts will be aimed at the preparation of cyanohydrins and other fine chemicals

through similar green chemical methods.

Keywords: Green Chemistry, riboflavin, enzyme mimics, dyes, oxynitrilase.





3,3’-of Functionalization of BINOL

Hiep Nguyen, Yuanda Hua, Parham Asgari, Junha Jeon*



Category: Graduate


BINOL and BINAP derivatives have facilitated an enormous set of stereoselective reactions including

various methods of carbon-carbon bond formation and catalytic heteroatom-transfer. In this talk, the

progress toward design and application of catalytic reductive ortho-C–H bond silylation with silyl acetals,

as traceless directing groups, for synthesis of a new class of 3,3’ bis-substituted BINOLs will be

presented. In detail, efficient syntheses of the 3,3’ bis-substituted BINOLs is achieved through from

dioxasilines, generated by a one-pot Ir-catalyzed ester hydrosilylation catalyzed with dialkyldihydrosilanes

and reductive Rh-catalyzed ortho-C–H silylation, by exploiting nucleophilic ring-opening addition with a

series of nucleophiles (e.g., Grignards reagents, organolithium reagents, and oxygen nucleophiles) as

well as arylation by Hiyama-Denmark cross-coupling. Moreover, the 3,3’ bis-silyl BINOLs can also be

triflated and subsequently subjected to the Au-catalyzed direct arylation to form a class of triflated 3,3’-

bis-aryl BINOLs, which can be further elaborated to 3,3’-functionalized BINAPs through the Ni-catalyzed

cross-coupling conditions.





Efficient mimicry of photosynthetic antenna-reaction center in supramolecular assemblies featuring BODIPY-Al(TTP) axially

coordinated to pyridyl appended fulleropyrrolidine

Habtom B. Gobeze,a Anthi Bagaki,b Georgios Charalambidis,b Asterios Charisiadis,b Christina Stangel,b

Vasilis Nikolaou,b Nikos Tagmatarchis,c,* Francis D’Souza,a,* Athanasios G. Coutsolelosb,*

aDepartment of Chemistry, University of North Texas, bDepartment of Chemistry, University of Crete, Laboratory of Bioinorganic Chemistry, Voutes Campus, 70013 Heraklion, Crete, Greece, cTheoretical

and Physical Chemistry Institute, National Hellenic Research Foundation; 48 Vassileos Contantinou Avenue, Athens 11635, Greece.


Category: Graduate Division: Analytical Chemistry

A series of new aluminum porphyrin based dyads bearing boron dipyromethene as an excitation energy/

secondary electron donor are synthesized. In order to study the effect of orientation of the energy donor

on the rate of energy transfer different linkers are used affording BDP-O-AlTPP and BDP-COO-AlTPP.

Moreover, these dyads were axially assembled with fullerene derivatives appended with pyridyl unit for

axial coordination to the aluminum center to study photoinduced electron transfer initiated from

aluminum porphyrin to fullerene (C60). The four studied triads (BDP-COO-AlTPP-C60-pyr, BDP-COO-AlTPP-

C60-PPV-pyr, BDP-COO-AlTPP-C60-PPV-pyr and BDP-O-AlTPP-C60-PPV-pyr) are shown in Figure 1. The optical

properties of the synthesized compounds were studied using steady state UV-Vis absorption and

fluorescence techniques. The excited state lifetimes were evaluated by time correlated single photon

counting method. The studied dyads BDP-O-AlTPP and BDP-COO-AlTPP exhibited ultrafast orientation

dependent efficient excitation energy transfer mimicking the antenna system of natural photosynthesis.

Electrochemical studies were performed to determine the feasibility of excited electron transfer from

aluminum porphyrin to the electron acceptor fullerene. Subsequently, femtosecond transient absorption

with a pulse excitation of 100 fs was used to study the occurrence of photoinduced electron transfer in

the triads. The studied triads exhibited ultrafast electron transfer initiated from 1AlTPP* to generate

BDP-AlTPP•+-C60•–. The charge separated states persisted for several nanoseconds prior returning to the

ground state.

Fig. 1 Molecular structure of studied triads.





Grubbs-Type Ruthenium Complex-Catalyzed Alkene-Silane Cross-

Couplings and Their Synthetic Applications

Apparao Bokka, Yuanda Hua, Adam S. Berlin, Junha Jeon*



Category: Graduate


Grubbs-type ruthenium-complex-mediated intramolecular alkene hydrosilylation of alkenylsilyl ethers has

been developed to provide cyclic silyl ethers with high regioselectivity. This non-metathetical use of such

ruthenium complexes for alkene hydrosilylation via preferential Si− H bond activation over alkene

activation is notable, where the competing alkene metathesis dimerization was not detected. In addition

to the synthesis of organosilicon heterocycles from readily available olefins, this study provides

fundamental mechanistic insights into the non-metathetical function of Grubbs-type ruthenium catalysts.

In the initial stage of hydrosilylation within a ruthenium coordination sphere, evidence for activation of a

ruthenium complex by direct σ -bond metathesis between Si− H and Ru− Cl via a four-centered transition

state is presented. This study counters the traditionally accepted Chauvin-type mechanism, specifi cally

the addition of R3 Si− H across the π -bond of a Ru-benzylidene.

We have also developed regio- and stereoselective dehydrogenative silylation and hydrosilylation of

vinylarenes with alkoxysilanes, catalyzed by ruthenium alkylidenes. Varying L- and X-type ligands on

ruthenium alkylidenes permits selective access to either (E )-vinylsilanesor β -alkylsilanes with high regio-

and stereocontrol. cis,cis -1,5-Cyclooctadiene was identifi ed as the most eff ective sacrificial hydrogen

acceptor for the dehydrogenative silylation of vinylarenes, which allows use of a nearly equimolar ratio of

alkenes and silanes.




Section 5

Organic/Biochemistry 1 Sid W. Richardson Physical Sciences Building: SWR 446


08:45-09:00 Jason B. Miller UT Southwestern Medical Center

The Design and Synthesis of Zwitterionic Amino Lipids for RNA Delivery and CRISPR Gene Editing

09:00-09:15 Lindsay Davis University of Texas at Arlington

Probing the active site of F420-dependent Glucose-6-Phosphate Dehydrogenase using steady-state and pre steady-state kinetic analysis

09:15-09:30 Jian Cao Southern Methodist University

Reaction-based Chemiluminescent Agents for in vivo Imaging

09:30-09:45 Noonikara Poyil University of Texas at Arlington

Large scale synthesis of Oligoanilines

09:45-10:00 Olatunji Ojo University of Texas at Arlington

General Approach Towards Linear (E) Allylic Compounds

10:00-10:15 Aditi Nagar Southern Methodist University

Efficient synthesis of circadian clock modulator: Delta Carbolines

10:15-10:30 Sulihat Mudasiru Texas A&M University – Commerce

Enantioselective Recognition of Chiral Porphyrins Diamino-1, 1-Binapthalene Hybrids

Organic/Biochemistry 1 SWR 446



The Design and Synthesis of Zwitterionic Amino Lipids for RNA Delivery and CRISPR Gene Editing

Jason B. Miller1,2, Shuyuan Zhang3,4, Petra Kos1,2, Hu Xiong1,2, Kejin Zhou1,2, Sofya S. Perelman5,

Hao Zhu3,4, and Daniel J. Siegwart1,2*

1Department of Biochemistry,

2Simmons Comprehensive Cancer Center, UT Southwestern Medical Center.

3Children’s Research Institute,

4Departments of Pediatrics and Internal Medicine,

5Department of Microbiology, UT Southwestern Medical Center.


Category: Graduate


CRISPR is a revolutionary gene editing technology with wide-ranging utility. To date, CRISPR delivery has

largely been accomplished using viruses, which have limited translational potential. The safe, non-viral

delivery of CRISPR components would greatly improve future therapeutic utility. We report the synthesis

and development of zwitterionic amino lipids (ZALs) that are uniquely able to (co)deliver long RNAs

including Cas9 mRNA and sgRNAs. A modular combinatorial synthetic design enabled rapid exploration

of a wide chemical space and the identification of a potent carrier, ZA3-Ep10. ZAL nanoparticle (ZNP)

delivery of low sgRNA doses (15 nm) reduces protein expression by > 90 % in cells. In contrast to

transient therapies (e.g. RNAi), we show that ZNP delivery of sgRNA enables permanent DNA editing

with an indefinitely sustained 95% decrease in protein expression. ZNP delivery of mRNA results in high

protein expression at low doses in vitro (< 600 pM) and in vivo (1 mg/kg). Intravenous co- delivery of

Cas9 mRNA and sgLoxP induced expression of floxed tdTomato in the liver, kidneys, and lungs of

engineered mice. The development of ZNPs provide a chemical guide for future rational design of long

RNA carriers, and represents a promising step towards improving the utility of gene editing.





Probing the active site of F420-dependent Glucose-6-Phosphate Dehydrogenase using steady-state and pre steady-state kinetic

analysis

Lindsay Davis1, Mercy A. Oyugi1, Ghader Bashiri2,3, Edward N. Baker2,3 Kayunta Johnson-Winters1*

1Department of Chemistry and Biochemistry, University of Texas at Arlington,

2Structural Biology Laboratory, School of Biological Sciences, The University of Auckland,

Auckland, New Zealand,

3Maurice Wilkins Centre for Molecular Biodiscovery, School of Biological Sciences, The

University of Auckland, Auckland, New Zealand


Category: Graduate


F420-dependent Glucose-6-Phosphate Dehydrogenase (FGD) is an essential enzyme found with

Mycobacteria tuberculosis, the causative agent of TB disease. FGD catalyzes the conversion of Glucose-

6-Phosphate (G6P) to 6-Phosphogluconolactone, using a unique cofactor known as F420. This reaction is

carried out as the first step of the Pentose Phosphate Pathway, which is important for nucleic acid

biosynthesis. A previous crystal structure of wild-type FGD led to a proposed mechanism, suggesting

that the active site residue His40 serves as the active site base, while Glu109 serves as the acid. Our

recent work has suggested that Glu109 is the active site acid. However, His40 does not serve as the

base. The goal of this present work is to determine which amino acid could possibly serve as the active

site base, using steady state and pre-steady state kinetic experiments as well as binding.





Reaction-based Chemiluminescent Agents for in vivo Imaging

Jian Cao, Alexander R. Lippert*



Category: Graduate


Chemiluminescence is the light emitted from a chemical reaction, and this newly generated light can be

used for detection and imaging purposes. No extra light excitation is required for the chemiluminescent

imaging, which provides a solution to the current dilemma that fluorescent probes encounter, such as

photoactivation and photobleaching. 1,2-dioxetane chemiluminescent scaffolds have been adapted by

our group for developing reaction-based imaging agents. A reactive handle is appended to this scaffold

and first reacts with the designated reactive species, followed by self-cleavage, and ultimately undergoes

a chemically initiated electron exchange luminescence (CIEEL) mechanism to produce light emission.

This design strategy has already been successfully applied for synthesizing chemiluminescent probes for

hydrogen sulfide (H2S) (CHS-3) and hypoxic conditions (HyCL-2). Those newly made probes display

instantaneous light emission upon reaction with specific reactive species that is sustained for over an

hour. Furthermore, CHS-3 and HyCL-2 have been successfully applied for H2S and tumor hypoxia imaging

in living animals using CCD camera technology. Furthermore, HyCL-3 has been made recently by

appending an acrylonitrile group into the 1,2-dioxetane scaffold, which dramatically increases

chemiluminescent emission and eliminates the use of Emerald II Enhancer (an enhancer used in our

previous study to enhance the light production). Work is being done towards developing a NIR

chemiluminescent scaffold which will open gates for deep tissure living animal imaging.





Large scale synthesis of Oligoanilines

Noonikara Poyil, A.; Bugarin, A.*



Category: Graduate


Oligoanilines are known for its vast variety of synthetic applications. Recently, oligoanilines have attracted

considerable research attention due to their conductive and physical properties. We have developed an

efficient large scale synthetic procedure to synthesize several oligoanilines with high purity. This method

reduces the formation of byproducts and gives products with high purity. The desired oligoanilines were

synthesized using few simple steps and employing routine purification methods. We will also present

their applications in conductive elastomers.





General Approach towards Linear (E) Allylic Compounds

Olatunji Ojo, Alejandro Bugarin*



Category: Graduate


Allylic compounds are one of the most valued building blocks in synthesis. The synthesis of several allylic

acetates and its derivatives employed two-step approach from readily available starting materials. The

approach afforded high yield in a metal-free procedure, ambient reaction conditions, with the linear and

(E)–conformer as the only adduct. The reactions are tolerant to many nucleophiles such as carbon,

nitrogen, oxygen, and sulfur given a high yield product. Our future goal is to extend the scope to

phosphorus nucleophiles.





Efficient synthesis of circadian clock modulator: Delta Carbolines

Aditi Nagar, Edward. R. Biehl, Brian D. Zoltowski*



Category: Graduate


Cryptochrome (CRY) is an important class of mammalian flavoprotein, which participates in various

metabolic pathways including sleep-wake cycle, hormone secretion in an auto-regulatory manner.

Biochemical studies have shown its involvement in regulating hepatic gluconeogenesis, hence, could be

a potential diabetes target. Recently, carbazole scaffolds have been demonstrated to bind the active site

of cryptochrome, however, it lacks critical H-bonding that can facilitate recognition and binding. In

contrast, carbolines, which contain two fused nitrogen rings, are important class of pyrido-indole

derivatives that could potentially introduce H-bonding characteristics to the carbazole scaffold. Notably,

these carboline scaffolds have been targeted as potential drug molecules. Specifically, beta-carbolines

occur widely in nature and have been studied as potential anti-cancer and anti-malarial

compounds. Delta-carbolines are less common in nature and historically been viewed as having cytotoxic

effects. To better understand the functional differences of carbazole, delta-carboline and beta-carboline

scaffolds we sought out to prepare analogs varying in the core scaffold. In the process, we have identified

two-step robust formation of delta-carbolines via reactions of benzyne and 2-halo-aminopyridines,

followed by microwave intramolecular cyclization.





Enantioselective Recognition of Chiral Porphyrins Diamino-1, 1-Binapthalene Hybrids

Sulihat Mudasiru, Stephen Starnes*



Category: Graduate


Biological molecules such as proteins exist as chirally pure single enantiomers which selectively

recognize chiral substrates or selectively catalyze the biosynthesis of single enantiomer chiral products.

This project aims to mimic biological molecules in the body. In this report, host complexes consisting of

tetraphenylporphyrins (TTP) diamino-1,1-binapthalene were synthesized by attaching (S)-(-) 2, 2-diamino-

1,1-binapthalene and (R)-(+)-2,2-diamino-1,1-binapthalene to TTP isocyanate in order to improve the

selectivity of this host in its chiral guest binding properties, with the ultimate goal of studying affinities of

host to the guests. Chiral guests studied were L-nicotine, R and S mandelate, and D-n-acetyl and L-n-

acetyl phenylalanine. Proton NMR, Mass spectrometry, UV-Vis and CD spectroscopy were used to

characterize the compounds and study their chiral host-guest binding properties. We proposed that R-

guests will bind selectively with R-TTP host molecules while S-guest will bind preferentially to S-TTP

molecules. L-Nicotine was found to show moderate selectivity with the S-TTP complex compared to other

guests studied that showed little to no selectivity in the host-guest complex. Future work will focus on

synthesizing new host-guest complexes and studying their chiral recognition properties.




Section 5



11:00 -11:15 Maha Aljowni Southern Methodist University

Synthesis of anti-cancer drugs to inhibit P-gp pumping action

11:15-11:30 Sampath B. Alahakoon University of Texas at Dallas

Improved Structural Arrangement in 2D Azine-linked Covalent Organic Frameworks upon Fluorination

11:30-11:45 Udaya Sree Dakarapu University of Texas at Arlington

Lewis Base Activation of Silyl Acetals: Iridium-Catalyzed Reductive Horner-Wadsworth-Emmons Olefination

11:45-12:00 Lawton A. Seal II University of Texas at Arlington

Studies Toward the Total Synthesis of (-)-Spiroleucettadine

12:00-12:15 Jayendra Chunduru Texas A&M University – Commerce

Isolation of a Pyrimidine Biosynthetic Pathway Mutant in Pseudomonas monteilii

12:15-12:30 Robert Green Southern Methodist University

Oxidative stress sensing mechanisms in ZEITLUPE




Synthesis of anti-cancer drugs to inhibit P-gp pumping action

Maha Aljowni, Alexander Lippert*



Category: Graduate


In recent years, many cancer chemotherapeutic agents have not shown much promise because they

have failed to accumulate in cancer cells long enough to have any effect. This is due to the overexpression

of a plasma membrane protein called P-glycoprotein (P-gp). Generally, the role of P-gp is to protect the

cells from any toxins or foreign substances by pumping these toxins (including chemotherapeutic drugs)

out of the cell. As part of my graduate research, biologists at SMU are using a computer-generated

model to predict the structures of P-gp inhibitors that can be synthesized in order to stop or inhibit the

action of P-gp. This model is proposed to help researchers stop P-gp pumping after docking with new

drugs and to understand the mechanism of it. Furthermore, my current research is focused on a

collaboration with the chemistry and biology departments for synthesizing multiple drug analogues that

can inhibit the P-gp protein. These are being tested in cancer cell lines for efficacy and strength of

inhibition so that future chemotherapeutic drugs can work effectively in cells.





Improved Structural Arrangement in 2D Azine-linked Covalent Organic Frameworks upon Fluorination

Sampath B. Alahakoon, Gregory T. McCandless, Arosha A. K. Karunathilake, Christina M.

Thompson, Ronald A. Smaldone*



Category: Graduate


Here, we report a structural analysis of a series of azine-liked 2D covalent organic frameworks (COFs)

synthesized utilizing two novel fluorinated monomers to their non-fluorinated equivalent. We found that

the fluorinated monomers could produce 2D-COFs with enhanced material properties. The fluorinated

COFs displayed BET surface areas over 2000 m2 g−1 compared to the non-fluorinated COF (760 m2 g−1).

And also, displayed more well-defined meso-pores with improved crystallinity. To get a greater insight to

the mechanism of formation, we studied the COF formation under varying reaction times and

temperatures.





Lewis Base Activation of Silyl Acetals: Iridium-Catalyzed Reductive Horner-Wadsworth-Emmons Olefination

Udaya Sree Dakarapu, Apparao Bokka, Parham Asgari, Gabriela Trog, Yuanda Hua, Hiep H

Nguyen, Nawal Rahman, Junha Jeon*

Department of Chemistry & Biochemistry, University of Texas at Arlington


Category: Graduate


Homologation of esters to α ,β -unsaturated esters is a useful transformation in organic synthesis. We

have developed a new approach for the Ir-catalyzed reductive Horner-Wadsworth-Emmons olefination of

esters; a one-pot method for the transformation of esters to α ,β -unsaturated esters utilizing silyl acetals

as aldehyde equivalents followed by Horner-Wadsworth-Emmons olefination. Lewis based activation of

silyl acetals formed by Ir-catalyzed hydrosilylation of esters initially generates putative penta-coordinate

silicate acetals which fragment into aldehydes, silanes and alkoxides in situ . The alkoxides deprotonate

phosphonate esters which subsequently react with the aldehydes to furnish α ,β -unsaturated esters.

Resulting α ,β -unsaturated esters are subsequently reduced chemoselectively. This method is

operationally simple compared with aluminium hydride-based reductive Horner-Wadsworth-Emmons

olefination. Notably, Horner-Wadsworth-Emmons olefination of traditionally challenging substrates such

as aryl, alkenyl and alkynl esters furnishes the corresponding α ,β - unsaturated esters at room

temperature with excellent stereoselectivities (E/Z > 20:1) and moderate to excellent yields (48–91%).

This transformation will contribute to enhancing the utility of silyl acetals in synthetic chemistry.





Studies Toward the Total Synthesis of (-)-Spiroleucettadine

Lawton A. Seal II, Carl Lovely*

Department of Chemistry & Biochemistry, University of Texas-Arlington


Category: Graduate


Total synthesis of natural products can lead to the innovation of new reactions, support or refute

proposed structural assignments of the isolated natural product, and provide sizable quantities suitable

for testing the biological activity of the compound. Our lab has devised a route for the total synthesis

spiroleucettadine, that not only would accomplish all three of the aforementioned scientific objectives,

but also, if successful, this would be the first reported total synthesis of this molecule. Our strategy was

to first utilize methodological techniques to thoroughly explore the scope of a novel oxidative addition

reaction previously discovered in our lab, and attempt to utilize it in a key step of our synthesis. With the

methodology study mostly completed, total synthesis of the molecule has commenced. During this oral

discussion we will present our findings thus far with respect to the methodology and total synthesis of

spiroleucettadine.





Isolation of a Pyrimidine Biosynthetic Pathway Mutant in Pseudomonas monteilii

Jayendra Chunduru, Thomas P. West*



Category: Graduate


The isolation of a pyrimidine biosynthetic pathway mutant in Pseudomonas monteilii ATCC 700476 was

investigated. Initially, the ATCC 700476 cells were subjected to chemical mutagenesis with 1%

ethylmethane sulfonate. The mutagenized cells were next subjected to two rounds of D-cycloserine (1

mg/ml) counter selection in glucose minimal medium for 2 hours at 30oC with aeration to eliminate wild-

type cells. The surviving cells were screened for uracil auxotrophy and one uracil auxotroph was

identified. This mutant grew at 30oC on uracil, cytosine or uridine when either 0.4% glucose or succinate

was the carbon source. Also, the uracil auxotroph grew on 50 mg/l orotic acid if glucose was the carbon

source. The activities of the pyrimidine biosynthetic pathway enzymes aspartate transcarbamoylase,

dihydroorotase, dihydroorotate dehydrogenase, orotate phosphoribosyltransferase and orotidine 5’-

monophosphate decarboxylase were measured in the mutant cells grown at 30oC on glucose or

succinate minimal medium containing uracil. The activity of dihydroorotase was found to be substantially

reduced in the mutant cells whether grown on glucose or succinate as a carbon source in the uracil-

containing medium. Overall, this study demonstrates that the isolation of a pyrimidine biosynthetic

pathway mutant strain from P. monteilii ATCC 700476 is feasible using conventional mutagenesis and

selection procedures.





Oxidative stress sensing mechanisms in ZEITLUPE

Robert Green, Brian D. Zoltowski*



Category: Graduate

Division: Biophysics

Organisms have evolved to sense and adapt to daily and seasonal environmental ques to maximize their

fitness through biological responses. Proteins containing Light, Oxygen, or Voltage (LOV) domains act at

signaling nodes to integrate oxidative stress, metabolism and light into circadian, reproductive and

stress pathways. In plants the ZEITLUPE (ZTL) family of blue-light photoreceptors are responsible for

integrating these signals into circadian and photoperiodic responses by allosteric regulation. These

mechanisms are likely conserved in plants, fungi and mammals but are still poorly understood. To better

understand the allosteric mechanisms that allow ZTL signaling, we focused on residue G46 which is in

close proximity to Q154, a residue involved in signal transduction. Mutating this residue to S46 forces

Q154 to a buried conformation which mimics the light-state. This allows direct analysis of the light-driven

global conformational response. Using chemical, biophysical, and in vivo approaches we have identified

oxidative stress sensing mechanisms in ZTL that integrate environmental stress, light and circadian

function.




Section 5



01:30 -01:45 Charles Ochoa Texas Christian University

Intramolecular deMayo Photocyclization: The Total Synthesis of Hippadine and Pratosine

01:45-02:00 Caleb M. Bunton Southern Methodist University

Catalyst controlled Thiol-Michael reactions for the study of catalyst efficiency

02:00-02:15 Shital Kale Southern Methodist University

Study of blue-light photoreceptor proteins in Soybean and Brassica rapa

02:15-02:30 Marlius Castillo Texas Christian University

Small molecule fluorophores as environmental probes

02:30-02:45 Christopher O. Obondi University of North Texas

Photoinduced charge separation in wide-band capturing, multi-modular bis(donor styryl)BODIPY-fullerene systems

02:45-03:00 Adam Montoya Texas Christian University

Steps towards the Synthesis of Phenanthridone Analogs

03:00-03:15 Vishal Rajat Sharma Texas Christian University

Triazine-substituted Hydrazones as Potential Drug Delivery Analogs




Intramolecular deMayo Photocyclization: The Total Synthesis of

Hippadine and Pratosine

Charles Ochoa, Dr. David E. Minter*



Category: Graduate


Various total syntheses of the Lycorine-type pharmacologically active alkaloids hippadine and pratosine

have been developed. However, most of these synthetic routes require prohibitively expensive materials

and/or achieve yields that are subpar, making these schemes unlikely to be used in an industrial setting.

Current research involves developing better synthetic methods for these two alkaloids starting with a

6,7-disubstituted isoquinoline. These syntheses are appealing since they utilize readily available starting

materials and avoid expensive catalysts. The key step in the synthetic scheme centers around an

intramolecular de Mayo photocyclization which involves a reaction between an alkene moiety in the

isocarbostyril system and a 1,3-diketone (a functionalized tether on nitrogen), which forms a third ring

in the structure of the molecule. Research on a model system (an isocarbostyril without the substituents

at positions 6 and 7) for these natural products has been done in order to elucidate the optimal

conditions for each step on the synthetic strategy. The established synthetic strategy led to compounds

along the synthetic route that had very undesirable solubility properties. To resolve this issue, the

substituents were replaced with bulkier, more non-polar moieties in order to increase the solubility of

the compound in ethyl ether.





Catalyst controlled Thiol-Michael reactions for the study of catalyst

efficiency

Caleb M. Bunton, David Son*

Department of Chemistry and Biochemistry, Southern Methodist University


Category: Graduate


The thiol-Michael addition reaction is a versatile tool that has recently found its way into the

toolbox of many chemists. Although this reaction follows a Michael addition reaction pathway,

the nucleophilic initiated thiol-Michael reaction may proceed under mild conditions, with the use

of a trace amount of catalyst, and may proceed quickly with high conversion. Ultimately the

efficiency of the nucleophilic initiated thiol-Michael addition rests solely on the nature of the

catalyst used. It is therefore important to determine the most efficient catalyst to utilize for a

specific chemical system, especially when the tuning of the properties of the final product is

desired.

In this study, a selection of amine catalysts was utilized in conjunction with multi-substituted thiol

and acrylate substrates to determine reaction efficiency in a catalytic mediated thiol-Michael

addition reaction. The efficiency of the catalytic mediated thiol-Michael reaction was determined

in terms of reaction completion rate in the presence of varying temperature, catalytic

nucleophilicity, as well as catalytic steric considerations. Increasing the efficiency of these

reactions facilitates the ability to produce a wide range of tunable designer materials at a large

scale while maintaining cost effectiveness.





Study of blue-light photoreceptor proteins in Soybean and Brassica rapa

Shital Kale, Brian Zoltowski*



Category: Graduate


Plants utilize light not only for growth and development but also to synchronize physiological process with

daily environmental changes. Arabidopsis thaliana is a useful model for plant circadian rhythms and

photoperiodic flowering. In Arabidopsis, LOV domain containing blue-light photoreceptors Zeitlupe (ZTL),

Flavin-Kelch-Fbox-1 (FKF1) and LOV-Kelch-Protein-2 (LKP2) are involved in the regulation of the circadian

clock and seasonal flowering. These plant photoreceptors contribute to agricultural productivity.

Therefore, we extended these plant photoreceptor studies to Soybean and Brassica rapa, the world’s

major agricultural crops. Sequence alignments of photoreceptor ZTL/FKF1 of Arabidopsis similar to

the Brassica rapa LKP2 families as well as Soybean ZTL/FKF1 family members. In order to understand

biological functions of Soybean and Brassica rapa, it is vital to understand its photocycle and chemical

activation. Accordingly, we studied photochemical characterization to confirm the recovery rates of

these LOV domain photoreceptors.





Small molecule fluorophores as environmental probes

Marlius Castillo, Sergei V. Dzyuba*



Category: Graduate


Fluorescence probes are notably important due to the numerous applications they have. This is the case

in BODIPY dyes which have been considered in biological and supramolecular labeling, photodynamic

therapy, material sciences and synthetic chemistry, among many others applications. Our interest in

BODIPY structures is given by its remarkable characteristics, such as high brightness and good solubility

and spectroscopy properties that can be easily tuned. It is our goal to develop BODIPY dyes that can be

used as viscosity sensors since this is one fundamental physical property in biological assemblies.

In this focus, we synthesized and studied two novel BODIPY based viscometers were through their

absorption, emission, and fluorescence lifetime in different solvents. Also, the unusual aggregation of

BODIPY fluorophores in 1,1-dichloroethane was analyzed using spectroscopy techniques. Furthermore,

we are currently investigating a porphyrin homodimer dye that might be capable of novel melting point

assessment of gels constituted of low molecular weight gelatin with molecular solvents and ionic liquids.

The applications of the presented contributions on environmental probes have the potential to help

develop and advance the analysis of biological systems between other research areas.





Photoinduced charge separation in wide-band capturing, multi-modular

bis(donor styryl)BODIPY-fullerene systems

Christopher O. Obondi,a Gary N. Lim,a Paul A. Karr,b Vladimir N. Nesterov,a Francis D’Souzaa,*

aDepartment of Chemistry, University of North Texas

bDepartment of Physical Sciences and Mathematics, Wayne State College


Category: Graduate


A series of multi-modular donor-acceptor systems capable of exhibiting photoinduced charge separation

have been designed, synthesized and characterized using various techniques. In this series, the electron

donor was a BF2-chelated dipyrromethene (BODIPY) appended with two styryl linkers carrying two

electron rich triphenylamine or phenothiazine entities. Fulleropyrrolidine linked at the meso-position of

the BODIPY ring served as an electron acceptor. As a result of extended conjugation and multiple

electroactive chromophore entities, the bis-styryl BODIPY revealed absorbance and emission well-into

the near-infrared region covering 300-850 nm spectral range. Using redox, computational, absorbance

and emission data, an energy level diagram was constructed that helped in envisioning the different

photochemical events. Spectral evidence for photoinduced charge separation in these systems was

established from femtosecond and nanosecond transient absorption studies. The measured rate

constants indicated fast charge separation and relatively slow charge recombination revealing their

usefulness in light energy harvesting and optoelectronic device building applications.





Steps towards the Synthesis of Phenanthridone Analogs

Adam Montoya, David E. Minter*



Category: Graduate


Phenanthridone-type alkaloids isolated from certain plants of the Amaryllidaceae family are of interest

due to their pharmaceutically active nature. The compounds are commonly used in research concerning

cancer, Alzheimer’s disease and other human illnesses. One of the main hindrances to such research

is the limited availability of many of these compounds. The Minter group is interested in the development

of procedures for synthesizing such alkaloids in a cost-effective and time efficient manner, while at the

same time maintaining fair to excellent yields. Techniques toward the synthesis of natural products of

the Phenanthridone type are presented herein. Manipulations were tested and optimized on a model

system in order to save both time and funds while developing a synthetic pathway to be utilized in the

formation of more complex compounds. Setbacks such as the reduction of a tetra-substituted double

bond have been encountered. However, adjustments are being made to avoid such difficulties in the

future. Ideally, the proposed scheme will ultimately allow for the synthesis of several phenanthridone

analogues.





Triazine-substituted Hydrazones as Potential Drug Delivery Analogs

Vishal Rajat Sharma, Eric E. Simanek*



Category: Graduate


The hydrazone functional group has been extensively studied due to its versatile applications, simple

synthesis, and unique structural properties. Among those, the acid-labile property can be utilized to

control hydrolysis rates at different pH conditions. Here, we exploited the triazine ring system to

introduce the hydrazone groups. To improve the solubility of hydrazones in water, the chlorine atoms of

the triazine ring were substituted by bigger polar groups, aminoethoxyethanol. Thus, substituted triazine

ring system can potentially be used to deliver drugs that have poor water solubility. The hydrolysis rate

of various hydrazones were studied under different pH conditions. Furthermore, presence of different

groups (-H, -CH3, or -C6H5) on N2 of the same hydrazone show different hydrolysis rates under the same

pH conditions. Among three groups on N2, hydrazones with –CH3 hydrolyzed the fastest as its electron

donating nature makes N1 more nucleophilic. This presentation introduces different hydrazones,

including their release studies in different pH solutions, as well as future plans for incorporating drugs

in our substituted triazine-ring systems.




Section 6

Physical/Computational Chemistry 1 Sid W. Richardson Physical Sciences Building: SWR 360


08:45-09:00 Peter Niedbalski University of Texas at Dallas

Dynamic Nuclear Polarization: Boosting 13C MRI Signals by >10,000-fold

09:00-09:15 Ahmad Najafian University of North Texas

DFT Study of Methane Activation by 3d Metal Alkoxides

09:15-09:30 Erik Antonio Vázquez-Montelongo University of North Texas

Computational Investigation of Intermolecular Interactions Between Functionalized Single-walled Carbon Nanotubes and Polyethylene Terephthalate

09:30-09:45 Qing Wang University of Texas at Dallas

Hyperpolarized 89Y-EDTP and 89Y-DTPP as pH Sensitive MRI Agents

09:45-10:00 Stephanie I. Jones Texas Christian University

Acid Catalyzed Hydrolysis of Lignin Model

Compounds with β-O-4 Linkages

10:00-10:15 Riffat Parveen University of North Texas

Effect of Ancillary Ligands on Oxidative Addition of CH4 to Re(III) Complexes: A = B, Al, CH, SiH, N, P Using MP2, CCSD(T) and MCSCF Methods

10:15-10:30 Christopher Parish University of Texas at Dallas

Mechanisms of 13C Dynamic Nuclear Polarization in a Mixture of Two Free Radicals

Physical/Computational Chemistry 1 SWR 360



Dynamic Nuclear Polarization: Boosting 13C MRI Signals by >10,000-fold

Peter Niedbalski, Christopher Parish, Qing Wang, Lloyd Lumata*

Department of Physics, The University of Texas at Dallas


Category: Graduate

Division: Physical Chemistry

Dissolution dynamic nuclear polarization (DNP) has become a widely used technique for created highly

polarized liquid-state solutions of nuclear spins that may then be monitored using nuclear magnetic

resonance (NMR) or magnetic resonance imaging (MRI). The already-impressive signal enhancements

gained through DNP can be further enhanced by the addition of trace amounts of gadolinium or holmium

ions to the sample. Typically, these ions are chelated within a stable ligand in order to render them inert

for biomedical applications. We have investigated the use of two other ions in the lanthanide family,

dysprosium and terbium, and found that they too yield significant 13C polarization enhancement. In the

case of terbium, polarization levels similar to those achieved with gadolinium may be reached with only

a fraction of the ion concentration required of gadolinium. In addition to terbium and dysprosium, we

have explored the use of gadolinium chelated in a novel trimeric ligand, 3-Gd, and found that its

performance as a DNP additive rivals that of conventional monomeric gadolinium complexes. The

physical mechanisms as to how to achieve 13C MRI signal enhancements of >10,000-fold will be

discussed.





DFT Study of Methane Activation by 3d Metal Alkoxides

Ahmad Najafian, Thomas Cundari*

Department of Chemistry, Center of Advanced Scientific Computing and Modeling (CASCaM),

University of North Texas


Category: Graduate

Division: Computational Chemistry

Conversion of methane (natural gas) to methanol, an easily transportable liquid, is an important reaction

to industry. In this study, the reaction pathway and thermodynamics for methane-to-methanol conversion

by first-row transition metal methoxide complexes are evaluated using density functional theory (DFT).

Three supporting ligands with different formal charges give an opportunity to evaluate different formal

oxidation states of the metal (MI, MII, MIII) as a factor to control the C-H activation reaction, as well as the

number of d-electrons on the metal. Several interesting conclusions have been derived thus far from the

calculations. First, d-orbital occupation plays a more significant role in controlling the thermodynamics

and kinetics of the methane activation reaction than either the metal formal charge and the properties

of the supporting ligand. Second, moving toward first row late-transition metals in periodic table showed

more thermoneutral reactions for 3d metal ions with high d-counts. Third, for the earlier 3d metals

studied thus far, the reaction seems to go through a four-centered transition state via a σ-bond

metathesis mechanism, but for the later 3d metals, activation of the methane C-H bond occurs through

an oxidative hydrogen migration mechanism.





Computational Investigation of Intermolecular Interactions Between Functionalized Single-walled Carbon Nanotubes and Polyethylene

Terephthalate

Erik Antonio Vázquez-Montelongo1,2, Adrián Rico-Campos3, Dalyndha Aztatzi-Pluma3,

Juan Francisco Javier Alvarado3, Edgar Omar Castrejón-González3, G. Andrés Cisneros1,2*

1 Department of Chemistry, University of North Texas, Denton.

2 Center for Advanced Scientific Computing and Modeling, University of North Texas.

3 Departamento de Ingeniería Química, Instituto Tecnológico de Celaya, Celaya, Gto. México.


Category: Graduate


Carbon nanotubes (CNTs) have been used as reinforcing agents for polymers. However, CNTs form

stable aggregates, which make it complicated to disperse them into the polymeric matrix. A popular

method to overcome this issue is by functionalizing the CNTs with compatible chemical groups with the

polymeric matrix. Therefore, knowing the specific type of functional group and its non-covalent

interactions with a given CNT is useful to achieve a proper CNT dispersion into polymeric matrices. Non-

covalent interactions analysis (NCI) and zeroth order symmetry-adapted perturbation theory (SAPT0)

calculations were performed to study intermolecular interactions of several single-walled carbon

nanotubes (SWCNT) functionalized with carboxyl (-COOH), amine (-NH2), hydroxyl (-OH) and phenyl (-Ph)

groups, interacting with a polyethylene terephthalate (PET) chain. We identified hydrogen bonds (HBs)

between donors from the functional groups on the SWCNT (-OH, -COOH and -NH2) and acceptors

(carbonyl oxygens) on the PET chain. Additional attractive interactions were observed between the

aromatic groups in the PET polymer chain and the SWCNT (PET/SWCNT-Ph and PET/SWCNT

interfaces). Details of the intermolecular interactions calculated with NCI and SAPT will be presented.





Hyperpolarized 89Y-EDTP and 89Y-DTPP as pH Sensitive MRI Agents

Qing Wang, Peter Niedbalski, Christopher Parish, and Lloyd Lumata*



Category: Graduate


Nuclear magnetic resonance (NMR) is widely used for decades due to its many advantages, but plenty

of low gyromagnetic ratio nuclei are limited by their inherent insensitivity, such as 89Y. However,

dissolution dynamic nuclear polarization (DNP) has made fast acquisition of 89Y NMR spectra possible by

producing a highly polarized liquid-state sample whose signal persists for relatively long time. This

technology successfully enhanced 89Y NMR signal greater than 60,000-fold. Due to this solid signal

buildup, 89Y complexes were found that they tend to be sensitive to pH. In order to study this interesting

phenomenon, two ligands, Y-EDTP and Y-DTPP, were chosen as candidates. They were polarized and

introduced into various pH buffers solutions, followed by high resolution NMR spectroscopy on these

samples, and their chemical shift dispersion was tested. The result shows that Y-EDTP behaves very well

that the chemical shift of it is highly dependent on different pH between pH 5.7 to 9.15 but no signal is

discovered below pH 5. On the other hand, the chemical shift of Y-DTPP is almost constant between pH

7 and 9. In comparison, 89Y-EDTP have more potential to be a pH sensitive agent in hyperpolarized MRI.





Acid Catalyzed Hydrolysis of Lignin Model Compounds with β-O-4

Linkages

Stephanie I. Jones, Benjamin G. Janesko*



Category: Graduate


Lignocellulose is produced at about 170 billion metric tons annually, but lignin (a component of

lignocellulose) is a waste stream in biorefinery processes. Lignin accounts for up to 40% by energy in

lignocellulose and is a polymerization of three major phenolic components: p-coumaryl alcohol, coniferyl

alcohol and sinapyl alcohol. The ratio between these components vary in different plants, wood tissues,

and cell wall layers. Improving lignin valorization is likely important for lignocellulose-based biorefineries

for there are only a limited number of utilizations in lignin derivatives. In this study, we use computational

chemistry to study two acid-catalyzed hydrolysis mechanisms of lignin model compounds: E1 elimination

and dehydration versus protonation and nucleophilic substitution.





Effect of Ancillary Ligands on Oxidative Addition of CH4 to Re(III) Complexes: A = B, Al, CH, SiH, N, P Using MP2, CCSD(T) and MCSCF

Methods

Riffat Parveen, Thomas R. Cundari*




Category: Graduate


A computational study for oxidative addition of methane to Re(OC2H4)3A (where A may act as an ancillary

ligand and thus can interact with the metal) was carried out. The choice of ancillary ligands have been

made based on their electronic properties: A = B or Al (Lewis acid), CH or SiH (electron precise), N (σ-

donor) and P (σ-donor/π-acid). The main objective of this study was to understand that how variation in

A affects the structural and electronic properties of the reactant d4-Re(III) complex, which can ultimately

tune the kinetics and thermodynamic of OA. Results obtained from MP2 calculations revealed that for

OA of CH4 to Re(OC2H4)3A, the order of ΔG≠ for a choice of ancillary ligand is B > Al > SiH > CH > N > P, thus

making Re(OC2H4)3P the best candidate for OA of methane. Single point calculations for ΔG≠ obtained with

CCSD(T) showed excellent agreement with those computed with MP2 methods. MCSCF calculations

indicated that oxidative addition transition states are well described by a single electronic configuration,

giving further confidence in the MP2 approach used for geometry optimization and ΔG≠ determination,

and that the transition states are more like the d4 Re(III) reactant than the d2-Re(V) product.





Mechanisms of 13C Dynamic Nuclear Polarization in a Mixture of Two Free Radicals

Christopher Parish, Peter Niedbalski, Qing Wang, Andhika Kiswandhi, Likai Song and Lloyd

Lumata*



Category: Graduate


Dynamic nuclear polarization (DNP) describes the transfer of the free radicals’ high electron polarization

to the nuclei via microwave irradiation of a diamagnetic sample homogeneously distributed throughout

a glassing matrix at low temperatures and high magnetic fields. Dissolution DNP extends this high

polarization to apply to liquids. As such, the properties of the free radical(s) used may significantly impact

the DNP results. We have examined the effect of varying the wide linewidth free radical 4-Oxo-TEMPO’s

concentration while in the presence of the narrow linewidth free radical trityl OX063 at optimum

concentration. The polarization profiles and intensities were compared for different 4-Oxo-TEMPO

concentrations. This study found that, if the sample was polarized about trityl OX063’s spin-up peak,

increasing 4-Oxo-TEMPO concentrations led to the intensity maxima decreasing before plateauing;

whereas, if the sample was polarized about trityl OX063’s spin-down peak, increasing 4-Oxo-TEMPO

concentrations led to the intensity maxima increasing and passing through zero before plateauing.

Additionally, the temperature-dependent electron spin resonance (ESR) behavior and ESR spectra were

acquired. Two possible mechanisms for this DNP behavior will be discussed.




Section 6



11:00 -11:15 Feng Wang Southern Methodist University

Atomic Details of Binding Modes between Antibiotics and Bacteria Cell Wall through Molecular Dynamics Simulations

11:15-11:30 Azadeh Nazemi University of North Texas

Control of C-H Activation by Mo-Oxo Complexes: pKa or BDFE?

11:30-11:45 Susana Aguirre-Medel University of Texas at Arlington

Porous Silicon Oxycarbide (SiCO) Materials

11:45-12:00 Siying Lyu Southern Methodist University

The Role of H-bonding in DNA

12:00-12:15 Zhicheng (Daniel) Sun University of North Texas

Computational Study of C-H Activation of Methane by Diiminopyridine Nitride Complexes

12:15-12:30 Vytor Oliveira Southern Methodist University

Exploring the Nature and Strength of Chalcogen Bonding for the Rational Design of New Materials




Atomic Details of Binding Modes between Antibiotics and Bacteria Cell Wall through Molecular Dynamics Simulations

Feng Wang, Hongyu Zhou, Sung Joon Kim, and Peng Tao*



Category: Graduate


Vancomycin is an antibiotic used as the first line treatment for many infections like skin and bloodstream

infections. It can inhibit the cell wall synthesis of Gram-positive bacteria through binding to the cell wall

structure. It is proposed that the vancomycin binds to a peptide chain of cell wall, and prevents the

completion of cell wall synthesis through crossing linking. Due to the limitation of experimental approach,

the atomic details of binding mode of vancomycin and the target peptide chain of cell wall structure are

yet to be obtained. To address this need, we carried out molecular dynamics (MD) simulation of the

systems of vancomycin bound with S.aureus peptidoglycan unit. We also carried out similar MD

simulations of vancomycin and desleucyl-vancomycin. Our simulations provided atomic details of

vancomycin and related compounds binding with cell wall peptide. According to our simulations,

desleucyl-vancomycin doesn’t bind to bacterial cell wall tightly even under restraints based on solid

nuclear magnetic resonance (NMR) experimental results. This agrees with the fact that desleucyl-

vancomycin is a much less antibiotic than vancomycin.





Control of C-H Activation by Mo-Oxo Complexes: pKa or BDFE?

Azadeh Nazemi, Thomas R. Cundari*




Category: Graduate


Based on previous research in our group, the deprotonation of a methyl ligand is a competing side

reaction in the reductive functionalization (RF) of metal-methyl complexes.1,2 In this research, a DFT study

was carried out to understand what controls the pKa of C-H bonds, and how these factors impact

competing and productive C-H functionalization processes. First, several levels of theory were calibrated

by optimizing 18 carbon acids for which experimental pKa’s are available. BMK/6-31+G(d)3 was thus

selected as the ideal basis set/functional combination for subsequent calculations, which involved C-H

activation of substituted toluenes by a Mo-oxo complex. Previous studies on RF of metal-methyl

complexes suggested Group 6 as a good target for catalytic functionalization of hydrocarbons.1 A

molybdenum-oxo complex (related to the active site of the enzyme, ethylbenzene dehydrogenase4) with a

potentially redox non-innocent supporting ligand was chosen as a catalyst to investigate C-H activation,

specifically benzylic substrates like toluene and meta/para-substituted-toluene. The purpose is to assess

whether pKa or the bond dissociation free energy (BDFE) – or some other factor – is more important

for facile C-H bond activation via deprotonation (C-H bond heterolysis) or H atom abstraction (C-H bond

homolysis), respectively, pathways.

1. Fallah, H.; Cundari, T, R.; Organometallics. 2016, 35, 950 - 958.

2. Fallah, H.; Cundari, T, R.; Comput. Theor. Chem. 2015, 1069, 86 - 95.

3. Ho, J.; Coote, M.; J. Chem. Theory Comput. 2009, 5, 295 - 306.

4. Szaleniec, M. et al. J. Inorg. Biochem. 2014, 139, 9 - 20.





Porous Silicon Oxycarbide (SiCO) Materials

Susana Aguirre-Medel, Peter Kroll*

Department of Chemistry & Biochemistry, University of Texas at Arlington


Category: Graduate


We report synthesis of porous silicon oxycarbide (SiCO) materials, their microstructural characterization

and performance in environmental applications. One of processes consists of reacting siloxane

precursors containing Si-H bonds with cross-linkers bearing vinyl groups using a platinum catalyst. The

reaction in diluted solutions (80-95 vol%) converts the siloxanes into aerogels after supercritical drying

in CO2. The other synthesis method involves hydrolysis and condensation reactions to obtain a cross-

linked gel which is slowly dried at 45 °C to obtain a porous material.

Porous SiCO materials are transformed via thermal treatment in controlled atmospheres into SiCO

ceramics. In addition, we augment the chemical synthesis by various treatments to tailor microstructural

and chemical properties of aerogels. We characterize the porous SiCO materials’ specific surface area,

nanoparticle size, pore size distribution, average pore size and total porosity. We emphasize the

microstructural tailoring by heat treatment atmosphere and additional post-synthesis methods. We

also study the potential applications of these materials, specifically the effects of different

microstructures on their properties.





The Role of H-bonding in DNA

Siying Lyu, Elfi Kraka,* Dieter Cremer

Computational and Theoretical Chemistry Group (CATCO), Department of Chemistry, Southern

Methodist University


Category: Graduate


The strands of the DNA double helix are hold together by the hydrogen bonds of the base pairs whereas

the strands themselves are influenced by the conformational flexibility of the deoxyribose rings, which

depends on their pseudolibration modes and the rotation of the side groups. The latter are also

influenced by hydrogen bonding, which couples pseudolibration and side group rotations.

In this work, the strength of the H-bonds keeping the various base pairs together is determined and

compared with that in the deoxyribose rings. Based on the calculated local stretching force constants

of the type O…H or N…H there is a clear preference of H-bonding in the base pairs compared to that in the

deoxyribose rings, which for the first time is quantified. H-bonding in the deoxyribose rings is undergoing

a large amplitude oscillation guided by the pseudolibrational motion of the five-membered ring.





Computational Study of C-H Activation of Methane by Diiminopyridine Nitride Complexes

Zhicheng (Daniel) Sun, Olivia A. Hull, Thomas R. Cundari*




Category: Graduate


2,6- diiminopyridine (PDI) complexes have been under intense investigation due to their catalytic ability

and versatility in binding many different metals and main group elements. Some known applications of

PDI complexes involve olefin polymerization, nitrogen-hydrogen bond activation, hydrosilylation, and

hydrogenation. However, there are few reported cases of carbon-hydrogen bond activation via PDI or

nitride complexes. The aliphatic C-H bond is thermodynamically strong and kinetically inert, making it

harder to activate, especially in light alkanes such as methane. Being able to functionalize cheap and

abundant light alkanes through catalysis can avoid traditional combustion technologies, which are

harmful to environment. In our studies, calculations were made using DFT methods and the Gaussian

09 software to study (PhPDI)MN [PhPDI = 2,6-(PhN=CMe)2C5H3N] (M = VIII, MnIII, FeIII, CoIII, NiIII, AlIII, PIII), and

their reactions with methane to form (PhPDI)M—N(H)CH3. Three different methane C-H bond activation

pathways were studied, including insertion, hydrogen atom abstraction (HAA), and [2+2] addition. Our

results show that early transition metals PDI nitride complexes favor the [2+2] pathway, while later

transition metals favor the HAA pathway. Activation barriers and free energy change of reactions were

calculated. Electron density analysis is used to examine the redox non-innocence of the PDI ligand in

these reactions.





Exploring the Nature and Strength of Chalcogen Bonding for the Rational Design of New Materials

Vytor Oliveira, Elfi Kraka*, Dieter Cremer




Category: Graduate


Non-covalent interactions guide the self-assembly of macromolecules such as proteins, DNA/RNA,

polymers, and are responsible for drug-receptor recognition, ion-transport, etc. Besides the well-known

hydrogen bonds, chalcogens (O, S, Se, Te) are also able to form short, directional, non-covalent

interactions, called chalcogen-bonding. Since this interaction is less explored than hydrogen bonding and

other non-covalent bonds, chalcogen compounds are interesting candidates for the development of

materials with unique properties. We studied 90 chalcogen-bonded complexes, calculated their local

stretching force constant, and analyzed their electron density distributions. We found out that most

chalcogen bonds involve the charge transfer of lone pair of a heteroatom A to the antibonding orbital

σ*(Y-E) involving the chalcogen E and a suitable atom (group) Y. The strength of chalcogen bonding

depends on the polarizability of E, polarizing power of Y, and electron donor ability of A. In a divalent

chalcogen, the second ligand can enhance the strength of the bond by withdrawing charge from the lone

pair of E and decreasing exchange-repulsion between E and A. There are more possibilities to fine-tune

a divalent chalcogen compared to a monovalent halogen or hydrogen. Based on this study, a receipt for

creating new chalcogen-bonded building blocks is given.




Section 6



01:30 -01:45 Yunwen Tao Southern Methodist University

Why does warm water freeze faster than cold water? - An explanation based on different ways of hydrogen bonding

01:45-02:00 Dineli Ranathunga University of Texas at Dallas

Molecular Dynamics Simulations of Glutathione coated Gold Nanoparticles

02:00-02:15 Hongyu Zhou Southern Methodist University

Direct Pathway Dynamics Sampling

02:15-02:30 Seunga Kim Texas A&M University – Commerce

Co-precipitation synthesis of palladium and cerium solid solution as efficient catalysts for selective hydrogenation of acetylene in ethylene

02:30-02:45 Li Shen Southern Methodist University

Catalytic Mechanism of β-Lactamases:

Chemical Driving Force behind Antibiotic Resistance

02:45-03:00 Alan Humason Southern Methodist University

Deciphering the Nature of the Pancake Bonding Interaction - Are these the Longest Bonds is Chemistry?




Why does warm water freeze faster than cold water? - An explanation

based on different ways of hydrogen bonding

Yunwen Tao,† Wenli Zou,† Junteng Jia,‡ Wei Li,‡ Dieter Cremer*,†

†Department of Chemistry, Southern Methodist University

‡Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic

Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, China


Category: Graduate


Water has many unusual physical and chemical properties, which are related to the network of hydrogen

bonds in the liquid. One of the most peculiar properties leads to the observation that warm water freezes

faster than cold water (Mpemba effect). Knowledge and use of the Mpemba effect goes back to Aristotle

(350 AC), Francis Beacon (1561-1626), or Rene Descartes (1596-1650) who all described the use of

this effect. The Mpemba effect is as interesting as it has been discussed controversially in the literature.

We investigated changes in the hydrogen bond network of liquid water using molecular dynamics

simulations. We could identify 36 different hydrogen bonding situations of which 16 are relevant for the

discussion. We determine the temperature dependence of H-bonding showing that at higher

temperature weaker H-bonds are broken whereas strong H-bonds dominantly remain. Our results

provide a molecular explanation of Newton’s law of cooling and the Mpemba effect.





Molecular Dynamics Simulations of Glutathione coated Gold

Nanoparticles

Dineli Ranathunga, Steven O. Nielsen*



Category: Graduate


Ligand coated gold nanoparticles have shown promise in many bio-medical applications such as cancer

detection, clinical chemistry, biosensors and targeted drug delivery. Use of glutathione as the ligand has

been shown to give a renal clearable fluorescent probe. The organization of the ligands on the gold

surface has been shown to affect the emission wavelength. The organization can be affected by the pH

and the ligand density. Here we show a general method to prepare glutathione coated gold nanoparticles

for study using molecular dynamics computer simulations. We determined that the ligand density

depends on the curvature of the gold surface and is smaller than that of straight chain ligands such as

alkane thiols. This general method will be applied to study the physical properties of different biosensors

built on this platform.





Direct Pathway Dynamics Sampling

Hongyu Zhou, Peng Tao*



Category: Graduate


Molecular Dynamics is a sophisticated method to deal with the protein dynamics problem. However, the

deficient sampling space in protein system becomes a limitation of this method. Therefore, enhancing

sampling has raised enormous interests in this area. In the current work, a new method named Direct

Pathway Dynamic Sampling has been developed. Here we applied a well-known reaction pathway

searching method, the Chain-of-States method, to perform molecular dynamics simulation. The result

has showed a strongly sampling efficiency increasing compared with normal simulations. Several testing

cases in different scales have been conducted. Starting with a simple example, alanine dipeptide, the

sampling efficiency has been thoroughly investigated. A complete contour plot has been generated to

show the sampling space. The huge sampling efficiency increasing of our method proved the

effectiveness of our method. Besides that, the beta-hairpin peptide folding process and beta-lactam

dissociation reaction process have also been thoroughly investigated. All those cases show a great

increasing sampling efficiency of our DPDS method compared with normal MD simulation. In conclusion,

the new developed method, Direct Pathway Dynamics Sampling has been successfully enhanced

sampling compared with normal molecular dynamics simulation.





Co-precipitation synthesis of palladium and cerium solid solution as

efficient catalysts for selective hydrogenation of acetylene in ethylene

Seunga Kim, Ben W.L. Jang*



Category: Graduate


Palladium based materials are well-known commercial catalysts for selective hydrogenation of acetylene

in ethylene for the multi-billion polyethylene industry. Recently, ceria has been demonstrated to show high

selectivity and considerable activity for selective hydrogenation at high temperatures. The objective of

this investigation is to develop ceria based catalysts with high activity and high selective for the selective

hydrogenation of acetylene in ethylene at lower temperatures. The approach is to combine Pd with ceria

into one catalyst system using the co-precipitation technique followed by post treatment procedures.

Such Pd-ceria catalysts with 0.15% and 0.2% of Pd have been synthesized and studied at various

temperatures, including 50℃, 75℃, 100℃, 125℃, 150℃, 175℃, and 200℃ after 1 hour of hydrogen

reduction at 200℃. The results show that the activity of 0.15%Pd-ceria is good with ~90% conversion

at 100C. However, its selectivity is below 0% due to the hydrogenation of ethylene in the feed. Calcination

at 600C decreases its activity but increases the selectivity. Further investigation on the effects of the

calcination time and temperature as well as hydrogenation reduction temperature on the behavior of

the catalyst will be studied and compared with the 0.2%Pd-ceria catalyst samples.





Catalytic Mechanism of β-Lactamases: Chemical Driving Force behind

Antibiotic Resistance

Li Shen, Peng Tao*



Category: Graduate


β-Lactamases are enzymes that hydrolyze β-lactam antibiotics. They are the main cause of antimicrobial

resistance, and continuously evolve adaptive mechanisms in a biological arms race with the development

of antibiotics. Elucidating and predicting β-lactamase evolution are crucial for the future development of

antibiotics with low or even no resistance. β-Lactamases cause antibiotics resistance by breaking the β-

lactam ring of antibiotics, rendering them ineffective. Therefore, we carried out hybrid quantum

mechanical and molecular mechanical (QM/MM) calculations within chain-of-states framework to

obtain minimum energy pathways (MEP) representing catalytic mechanisms of key β-lactamases. These

pathways from different β-lactamases are superimposed and compared to shed lights on evolution of β-

lactamase catalytic mechanisms. TEM-1(class A), DD-peptidase and penicillin binding protein A (PBP-A)

are investigated. Key structures along the reaction pathways of TEM-1, DD-peptidase and PBP-A are

superimposed. The results show that these proteins have similar structures along the pathways.

Reaction mechanism of penicillin-G hydrolysis is conserved among TEM-1 (Class A β-lactamase), DD-

peptidase and PBP-A, confirming our hypothesis that catalytic mechanisms are conserved among these

related proteins.





Deciphering the Nature of the Pancake Bonding Interaction – Are

these the Longest Bonds is Chemistry?

Alan Humason, Dieter Cremer*




Category: Graduate


Free radical molecules are generally short-lived because of their tendency to selfdimerize into more

stable covalently bonded species. Mulliken proposed that novel chemistry could be observed by creating

a sterically hindered free radical molecule, which could not dimerize, due to steric repulsion. He named

this proposed, but unobserved, interaction ‘pancake bonding.’

Once synthesized, studies of magnetic properties and X-ray structures of these pancake bonded

compounds found that the molecules exist as stacked dimers, at distances longer than normal covalent

bonding distances, but shorter than the sum of their van der Waals radii. This led to speculations about

the nature of the interaction.

In this work, we employ quantum chemistry (Coupled Cluster and DFT methods) to study the bond/dimer

dissociation energies of five pancake bonded species. We use the analysis of vibrational modes to

determine the local stretching force constants between the dimers, which give a reliable measure of the

strength of the interaction between them. We use the critical points of the electron density distribution

to characterize the interactions between the monomers. We demonstrate that pancake bonding is not

a covalent bonding interaction, and that the so-called ‘pancake bonds’ are a result of dispersion

interactions between two radicals.




Presenters Index

Presenting Author Page # Presenting Author Page #

Adam Montoya 109 Gayan A. Appuhamillage 78

Aditi Nagar 94 Habtom B. Gobeze 86

Ahmad Najafian 113 Hannah Johnston 55

Alan Humason 132 Hector Villegas 15

Alexander T. Brown 46 Hiep Nguyen 85

Anne D’Achille 63 Hongyu Zhou 129

Anthony B. Samuel 14 Iain W. H. Oswald 26

Apparao Bokka 87 Jacob W. McCabe 67

Apsara K. Herath 83 Jason B. Miller 89

Audrey Reeves 13 Jason Lin 30

Avichal Vaish 41 Jayendra Chunduru 101

Azadeh Nazemi 121 Jian Cao 91

Brandon J. Foley 22 Jonathan Buford 57

Brian L Kamras 49 Joshua Burge 20

Brooke M. Otten 40 Joshua F. Ivy 51

Caleb M. Bunton 105 Juan P. Vizuet 31

Charles Ochoa 104 Katherine A. Benavides 43

Christiana Agbo 18 Kelly Schostag 12

Christopher O. Obondi 108 Kenneth J. MacKenzie 59

Christopher Parish 118 Khaled Shennara 61

Christopher Williams 58 Kortney M. Melancon 47

Daniel Korir 54 Lauren M. Harris 34

Darrell D. Mayberry 27 Lawton A. Seal II 100

Diego F. Zometa 9 Li Shen 131

Dineli Ranathunga 128 Lindsay Davis 90

Do Nguyen 44 Luke Ryan 80

Enrique Barragan 73 Mackenzie Young 11

Erik Antonio V. Montelongo 114 Maddie M. Barnett 7

Erin N. Benton 38 Maha Aljowni 97

Feng Wang 120 Maribel Barrera 5



Presenting Author Page # Presenting Author Page #

Marlius Castillo 107 Sinjinee Sardar 64

Melissa Orr 4 Siying Lyu 123

Miguel E. Quimbar 21 Stephanie I. Jones 116

Mikaela Wilk 29 Stephen M. Budy 77

Misty S. Martin 19 Sulihat Mudasiru 95

Mohammed Irfan Zakir Omer 62 Susana Aguirre-Medel 122

Nimmy Mammoottil 75 Swetha Chinthala 70

Noonikara Poyil 92 Taniya M.S.K. Pathiranage 68

Olatunji Ojo 93 Tharun T. Ponduru 48

P. Sotelo 50 Thirupataiah Avullala 76

P.B Jayathilaka 52 Thomas Howlett 16

Parham Asgari 69 Udaya Sree Dakarapu 99

Patricia Nance 6 Vishal Rajat Sharma 110

Pawan Thapa 84 Vytor Oliveira 125

Peter Niedbalski 112 Waleed Yaseen 28

Philip M. Palacios 36 Wijayantha A. Perera 37

Qing Wang 115 Yakun Cao 33

Rajesh Kumar 65 Yi Hu 71

Ravi P. Singh 82 Yixin Ren 25

Riffat Parveen 117 Yunwen Tao 127

Robert Green 102 Zhicheng (Daniel) Sun 124

Ruaa Almotawa 56

Samantha M. Brewer 35

Sampath B. Alahakoon 98

Samuel Weber 23

Sanjana Ravi 8

Seunga Kim 130

Seyed Majid Farvid 42

Shital Kale 106

Shivaraj Yellappa 72

Shreya Patel 3

Shuai Shao 79

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