studies of cluster-assembled materials: from gas …

The Pennsylvania State University

The Graduate School

Department of Chemistry

STUDIES OF CLUSTER-ASSEMBLED MATERIALS

FROM GAS PHASE TO CONDENSED PHASE

A Thesis in

Chemistry by

Lin Gao

copy 2008 Lin Gao

Submitted in Partial Fulfillment of the Requirements

for the Degree of

Doctor of Philosophy

May 2008

The thesis of Lin Gao was reviewed and approved by the following

A Welford Castleman Jr Evan Pugh Professor of Chemistry and Physics Eberly Distinguished Chair in Science Thesis Advisor Chair of Committee

Thomas Mallouk DuPont Professor of Materials Chemistry and Physics

Ayusman Sen Professor of Chemistry Head of the Department of Chemistry

Elizabeth Dickey Associated Professor of Material Science and Engineering Associate Director of Material Research Institute

Signatures are on file in the Graduate School

iii

Abstract

Clusters defined as ldquoa number of similar things that occur togetherrdquo in Websterrsquos

dictionary has different meanings depending on the given subject To physicists and

chemists the word cluster means ldquoa group of atoms or molecules formed by interactions

ranging from very weak van der Waals interactions to strong ionic bondsrdquo Unlike

molecules which are made by nature and are stable under ambient conditions clusters

discovered in a laboratory are often metastable Molecules have specific stoichiometry

whereas the clusterrsquos composition can usually be altered atom by atom Thus clusters can

be taken as intrinsically ldquoartificial moleculesrdquo with considerably more tunabilities in their

properties Research into the relative stability and instability of clusters has in recent

years become a very active research area especially following the study by Khanna and

Castleman that first suggested that by varying size and composition clusters can expand

the periodic table to the 3rd-dimension that is clusters can mimic the chemistry of atoms

and may therefore be used as the building blocks of new materials

The discovery of Met-Cars has drawn worldwide interests and has been actively

investigated by researchers from a variety of fields including physics chemistry and

material science However the unsuccessful search for a solvent capable of isolating

Met-Cars has impeded progress in characterizing the material in the condensed state and

hence limited its potential applications as a novel nanoscale material An alternative

iv method involving the deposition of mass-gated species and the subsequent structural

investigation via Transmission Electron Microscopy (TEM) has been employed With

particularly interesting results soft-landed deposits of zirconium Met-Cars were found to

form a face-centered-cubic (FCC) structure with a lattice parameter ~ 15Aring

The production of Met-Cars is conducted with the direct laser vaporization (DLV)

of metalgraphite composite pellets After being mass gated in a reflectron equipped

time-of-flight mass spectrometer (TOF-MS) and deposited onto TEM grids the resultant

specimens can be loaded onto high-resolution TEM investigation via electron diffraction

In conclusion soft-landing of mass selected clusters has been shown to be a

successful approach to obtain structural information on Zr-Met-Car cluster-assembled

materials collected from the gas phase TEM images indicate the richness of the

morphologies associated with these cluster crystals However passivation methods are

expected to be examined further to overcome the limited stabilities of these novel

clusters From this initial study itrsquos shown the promising opportunity to study other Met-

Cars species and more cluster-based materials

Experimental results of reactions run with a solvothermal synthesis method

obtained while searching for new Zr-C cluster assembled materials are reported One

unexpected product in single crystal form was isolated and tentatively identified by X-ray

diffraction to be [Zr O(OH) O ]middot2[N(Bu) ] 6i

12 6 4 with space group P21n and lattice

parameters of a =1244 Aring b=2206 Aring c =1840 Aring α = 90deg β = 105deg γ = 90deg V = 4875

Aring 3 and R1=315 for the total observed data (I ge2 σI) and ωR2 = 282 This novel

hexanuclear Zr(IV)ndashoxo-hydroxide cluster anion may be the first member in

v polyoxometalates class with metal atoms from the IVB group and having Oh symmetry

Alternatively it may be the first member in [(Zr6Z)X12]X6m- class with halides replaced

by oxo- and hydroxyl groups and with an increased oxidation state of Zr It is predicted

to bear application potentials directed by both families This work could suggest a

direction in which the preparation of Zr-C cluster-assembled materials in a liquid

environment may be eventually fulfilled

13-Bis(diethylphosphino)propane (depp) protected small gold clusters are studied

via multiple techniques including Electrospray Ionization Mass Spectrometry (ESI-MS)

Ultraviolet-Visible Spectroscopy (Uv-Vis) Nuclear Magnetic Resonance (NMR) for

solution phase and Transmission Electron Microscopy (TEM) for the condensed phase

In particular undeca- dodeca- and trideca-gold clusters protected by depp and halogen

ligands ie[Au11-13(depp)4Cl2-4]+ are found to be all predominant and persist in solution

for months while they gradually and spontaneously grow into a monomial tridecagold

clusters series The unique preferred ligand combination depp along with Cl is

discussed in terms of the ligand-core interaction and the closed-shell electronic

configurations of the Aun (n=11-13) cores which enables them to serve as building units

for larger cluster-assembled nanoparticles and form Self-Assembled Arrays (SAAs) as

discovered by TEM measurements Such spontaneous-growth behavior and the resultant

SAAs observations are correlated by icosahedra-close-packing modes of clusters

following ldquomagic numbersrdquo rules ~7 shells of such cluster packing are proposed to be in

the SAAs

vi Table of Contents

Chapter 1 Introduction1

11 Background Introduction 1 12 Motivation5 13 Thesis Organization 11 14 References13

Chapter 2 Mass Deposition and Preliminary Structural Study of Met-Cars via Transmission Electron Microscopy (TEM)18

21 Abstract18 22 Introduction20 23 Experimental22 24 Results24 25 Discussion28 26 Conclusion 33 27 Acknowledgements35 28 References35

Chapter 3 Application of Solvothermal Synthesis to IsolateSynthesize Cluster-Assembled Materials in a Liquid Environment38

31 Abstract38 32 Introduction39 33 Experimental46

331 Material Synthesis 46 332 Single Crystal Growth 48 333 Structures Determination49 334 Mass Spectrometry Analysis 50 335 Other Techniques for All Immediate Analysis51

34 Results52 341 Start with ZrCl4 (Case I)52 342 Start with Zr-graphite Soot (Case II) 53 343 Start with ZrC (Case III)54 3431 By-products 54 3432 Significant Crystallographic Results 56 3433 Mass Spectrometric Results 65

35 Discussion68 351 Atomic Arrangement in the Structure 68 352 Mass Spectra70 353 Classification 74 354 Possible Formation Pathway 76

vii 355 What is the origin of the organic cation78 356 Prospects79 357 How likely could the ligands be alkyl groups 81 358 Repeatability and Future Work 86

36 Conclusions88 37 Acknowledgements90 38 References91

Chapter 4 Studies on Small Monolayer Protected Gold Clusters (Au-MPCs) Ligand-core Interactions Spontaneous Growth and Self-Assembling103


431 Materials and Preparation107 432 Characterizations 109 433 Calculation111

44 Results112 441 ESI-MS and Uv-Vis Spectra on Fresh Products112 442 ESI-MS and Uv-Vis Spectra on Aged Products115 443 P-NMR31 122 444 TEM125

45 Discussion131 451 Au -MPCmdash a Model Cluster for Comparison Studies11 131 452 Au -MPC mdash the Destination as well as the Starting Point13 133 453 Au -MPC ndash- a Missed Entity in Mingosrsquo ldquoMaprdquo12 136 454 Each Atom Matters138 455 Aggregation and Self-Assembling of Small Au-MPCs

Speculations 140 46 Future Work143 47 Conclusions143 48 Acknowledgements144 4-9 References 145

Chapter 5 153

Conclusion Remarks 153

References155

Appendix A156

Zr-Met-Cars Deposition from Direct-Laser Vaporization (DLV) Source Technique Chemical and Crystallographic Difficulties 156

viii A1 Technique Limitations 156 A2 Chemical Reactivities 161 A3 Crystallographic Challenges 162 A4 Summary and Prospective 164 A5 Acknowledgements166 A6 References166

Appendix B 169

Supporting Information for Chapter 4 169

B1 Proposed two-step vs one-step reaction kinetics169 B2 Supporting Uv-vis and ESI-MS for TEM results172 B3 Supporting ESI-MS and H-NMR for Figure 4-5c1 174 B4 Detailed analysis of all small peaks presented in Figure 4-5176 B6 Summary of Uv-Vis on Au to Au11 13181 B7 References183

Appendix C185

Calibration Documents of Negative-MALDI1 185

ix List of Figures

Figure 1-1 Stable clusters with closed-shell electronic structure have the potential to mimic the properties of atoms in the periodic table to expand it into 3D (from reference )6 2

Figure 1-2 C60 with I symmetry (from reference )h15 3

Figure 1-3 Mass distribution of Ti C clusters generated from the reaction s of titanium with CH ( from reference )

m n+

4 12 5

Figure 1-4 The optimized geometries of the Ti C with various symmetries (from reference )

8 1240 7

Figure 1-5 Two views of the Td structures of Met-Car (from reference ) with emphasis on M-C π bonds and M-C σ bonds (spheres in light Ti in dark C)

45

2 2 8

Figure 1-6 Proposed Met-Car cage (T ) and double- triple- and quadruple-cage the metal atoms are represented in purple and the carbon atoms are represented in green (from reference )

h

49 8

Figure 1-7 Various of dimmer structures (from reference )40 9

Figure 1-8 Calculated B C of Met-Car stoichiometry in solid FCC phase shown to be metallic and with strong electron-phonon coupling and high T superconductive behaviors (from reference )

8 12

c60 10

Figure 1-9 Illustration of the potential hydrogen storage application of Met-Cars to achieve up to 56 wt H capacity approaching the minimum requirement of 6 wt for practical applications (from reference )27 11

Figure 2-1 Schematic of the experiment setup a)overall configuration b)hard landing c) soft-landing deposition arrangements Note that during the soft-landing deposition of the mass gated packets the species are deposited with a small distribution of energies arising from the spatial distribution in the extraction region of the time-of-flight (slightly modified from reference with permission)

20

23

Figure 2-2 The subparts (i) (ii) and (iii) indicate images taken from different area in the TEM specimen (A) HRTEM images of ZrC deposits mass gated at Zr8C12 The species were deposited with ~228 kV of kinetic energy (B) Two-dimensional fast Fourier transformations (FFT) of the images The sketches show the d-spacings obtained from the FFT images that correspond

x to the above images respectively Errors associated with the FFT are evident from the asymmetry of the d-spacings shown in the sketches (modified from reference with indexing analysis results)20 25

Figure 2-3 HR-TEM images of soft-landed ZrC species mass gated at Zr8C12 (A) and corresponding diffraction pattern (B) (scale bar 15 nm) (modified from reference with indexing analysis results)20 27

Figure 2-4 Courtesy contribution and cited with permission theoretical calculation supports the proposed FCC packing for Ti-Met-Cars (in T symmetry) solids

27

d30

Figure 3-1 Ti-Met-Car reaction with pyridine and methyl alcohol9 10 42

Figure 3-2 Structures of (left) Kegginrsquos ion and (the right) and [(Zr ZX )L ](M=metal Z=interstitial atom X=halogen atoms with two position X and

X )

696 12 6

m-

52 i

a 44

Figure 3-3 Basic illustration of experimental setup 47

Figure 3-4 Crystals in mother liquor (30times)48

Figure 3-5 Single-crystal reflection resolved C H N structure (blue-shaded ball N gray-shaded C hydrogen was omitted for clarity adopted from )

6 14 4101 53

Figure 3-6Ball-stick presentation of the crystal structure of [Zr O(OH) O ]middot 2[N( Bu) ] Atoms are number- as well as color- labeled The centre oxygen is O100 and bridging oxygen atoms are O10 ( =1 to 12) Colored labels red for oxygen green for zirconium and blue for nitrogen gray for carbon

6 12 6n-

4

56

Figure 3-7 Ball-stick presentation of the crystal structure of [Zr O(OH) O ]middot 2[N( Bu) ] (From the top left to the right) views from four-fold and three-fold axes and (the bottom middle) the packing for one unit cell (colored lines represent a (red) b(green) c (blue) axes respectively) Colored labels red for oxygen green for zirconium and blue for nitrogen gray for carbon Notice the relative orientation and distance between the red and the gray balls which indicates that strong hydrogen bonding Hydrogen atoms are omitted for clarity

6 12 6n-

4

58

Figure 3-8 The measurements of selected bond angles (top) the result table (middle) and the schematic representation of the bisect view (bottom) with the averaged angles labled 116deg (Zr- O-Zr) 90deg (Zr- O-Zr) 103deg ( O-Zr-O)

micro i oxo

micro 64

xi Figure 3-9 Negative-ESI-MS results convey the stoichiometric information

which can rationalize all major peaks to be associated with one anionic species [Zr O(OH) O ] (inset blown-up region around 8804 amu right (experimental) and left (simulated) )

6 12 62-

66

Figure 3-10 Negative-MALDI result exhibits a protonated [Zr O(OH) O ][H] peak with 2 amu shift compared with the simulated (inset) pattern See detailed discussion in the text

6 12 6-

67

Figure 3-11 Three types of M -ligand clusters (Taken from reference )680 76

Figure 3-12 hypothesized ldquoprototyperdquo cluster in 3D lattice prior to being excised5076

Figure 3-13 Proposed linking modes enabling the Zr super lattice with chiral properties

6105 81

Figure 4-1 Diphosphine ligands involved in this report 1 3-Bis (diphenylphosphino) propane (dppp) and 1 3-Bis (diethylphosphino) propane (depp) and other starting materials The bottom box shows the potential degradation fragments P1 and P2 for short of depp induced upon oxidation (Note Ph = C H Me = middotCH Et = C H Pr = C H as chemical convention)

6 5 3 2 5 3 7108

Figure 4-2 (a) The representative ESI-MS of the fresh Audepp solution with the predominant peak of [Au depp (PPh ) Cl ] (3421 mz) and (b) Equation 4-1 chemical reactions for the formations of [Au depp Cl ] (3117 mz) and [Au depp (PPh ) Cl ] (3421 mz)

11 3 3 2 2+

11 4 2+

11 3 3 2 2+ 113

Figure 4-3 The Uv-Vis of a) the fresh Audepp solution (inset un-zoomed whole spectra) and b) the precursor AuClPPh (both are taken in 11 MeOhCHCl solvent)

3 3114

Figure 4-4 Comparison of the Uv-Vis of the aged Audepp (in orange solid line) with the fresh Audepp (already seen in Figure 4-3 now in red and dashed line) Both are taken in 11 MeOhCHCl solvent3 115

Figure 4-5 Periodic measurements on Audepp solutions as-prepared by ESI-MS (diluted in MeOH ~ 15) reveals an interesting spontaneous growth behavior The relative ratio of [Au (depp) Cl ] to [Au (depp) Cl ] to [Au (depp) Cl ] gradually switches toward the higher mz range

11 4 2+

12 4 3+

13 4 4+ 117

Figure 4-6 Close examination at the peaks beyond the depp-oxidation adduction in Figure 4-5 reveals more dodeca- and tridecagold-based cluster series

xii More profoundly they were found to be ldquoscavengedrdquo during the conversion toward tridecagold 119

Figure 4-7 Mass assignments for a) [Au (depp) Cl ] (3117mz) [Au (depp) Cl ] (3551 mz) [Au (depp) Cl ] (3583 mz) b) [Au (depp) Cl ] (3583 mz) and [Au (depp-O) Cl ] (3599 mz) were confirmed by the isotope pattern simulated by MassLynx 30

11 4 2+

12 4 3+

13 4 4+

13 4 4+

13 4 4+

80 121

Figure 4-8 Proposed chemical equations 2 and 3 for cluster aggregation in presence of precursor from Au to Au and Au 11 12 13 122

Figure 4-9 P-NMR spectra of a) pristine depp (unbound free ligand) b) precursor AuClPPh c) aged (95months) Audepp measured in CDCl

31

3 3 123

Figure 4-10 Bright-field TEM images a) to d) for AuDepp solution with different concentrations all exhibit narrow size distributions as shown with the histograms in e) and f) EDS g) elemental information provides further evidence for the core-ligand composition inferred from ESI-MS (Philips EM-420T)127

Figure 4-11 HR-TEM (bright-field images) on particles in Figure 4-10 c) from fresh Audepp solution without dilution (JEOL EM-2010 LaB )6 128

Figure 4-12 Bright-filed TEM images of the zoomed view of Figure 4-10 d) from fresh and concentrated Audepp products solution (scale bar 40 nm taken on Philips EM-420T)128

Figure 4-13 a) HR-TEM images of the as-prepared Au-MPCs b) the global FFT and c) the selected-area FFT both reveal lt111gt as the preferred orientations of the Au-MPCs on such 2-D structures (JEOL EM-2010F at 200kV) 129

Figure 4-14 Proposed surface potential diagram for the auto-cluster-conversion the multiple ldquoblue linesrdquo represent a few metastable states (in Figure 4-5 and 4-6) close-lying to the [Au depp Cl ] the energy barrier from Au to Au to Au are supposed to be low Thus the profile of the surface potential is supposed to be very soft

13 4 4+

11 12

1370137

Figure 4-15 Idealized nanoclusters of close-packed icosahedron with one to five shells of atoms together with the numbers of atoms (magic numbers) in these clusters (reproduced with permission from )65 142

Figure 4-16 Equation 4 for he total number of atoms N in a Mackay icosahedron composed of K shells where K is referred to as the shell index in the given equation below K is defined to be 0 for the central atom

64

142

xiii Figure A-1 Mass-gating effect showing that only signals (baseline width of

~13micros) of Zr-Met-Cars are selected from the equation derived (inset) the energy dispersity of species in the ~13 micros time window is ~350V (S = ~260 m m =872 amu q =1 e)

9

8

158

Figure A-2 Second-Ion Mass Spectrometry (SIMS) of the Zr-Met-Cars deposit on TEM grid as prepared reveals much more low-mass species which is supposed to be at least partially from the defragmentation of Zr-Met-Cars upon landing on the surface

10

159

Figure A-3 Energy Dispersive Spectra (EDS) (left) and the corresponding bright-filed TEM images (right) of contaminant deposit The source of such contaminants is not clear 160

Figure A-4 X-ray Photo Spectroscopy (XPS) measurement on as-deposited Zr-Met-car on TEM grids data deconvolution reveals 8 binding modes which can be classified into ZrO (495) ZrC (368) Zr(0) (45) There are other two peaks at 18096 eV (545) and 17855 eV (363) could be potentially assigned to be the binding modes in Zr(0) with 11 and -03 relative error respectively These results suggest the O -sensitivity of Zr-Met-cars and the landing-energy induced decomposition of Met-cars into carbides

2

2

162

Figure A-5 Nanocrystals observed from the deposited species However the Selected-Area Diffraction Pattern (SADP as the inset) reveals the d-spacing of ZrC [220] planes (~235Aring) from lt100gt zone axis164

Figure A-6 Schematic design of newly funded instrumentation165

Figure B-1 ESI-MS of fresh Audepp clusters a) Occasional observation of monodispersed [Au11(depp)4Cl2]+ in the high mass range b) higher population of 3117 mz over 3421 mz was achieved by having higher ratio of depp in the starting materials170

Figure B-2 Kinetic mechanisms with 11 ratio of depp gold precursor the production of [Au11depp3(PPh3)2Cl2]+ (3421 mz) is favored with 141 ratio the production of [Au11depp4Cl2]+ (3117 mz )is favored with ratio in between mixed effect is observed Along the time kinetic factors becomes leveled off by thermodynamic factors thus more depp-substituted [Au11depp4Cl2]+ is formed171

Figure B-3 The Uv-Vis absorption of Audepp clusters measured at a series of timing points on a Hewlett-Packard 8453 diode-array spectrometer The spectra were recorded as ldquotiffrdquo file by the Agilent ChemStation software (inset an independently measured Uv-vis on fresh Audepp prepared in the

xiv same way as reported in Chapter 4 was collected on a dual beam Varian Cary 3C Uv-Vis spectrophotometer at NIST )4 172

Figure B-4 Pre-TEM analysis (for Figure 4-9 and 4-11) on Audepp product solution via ESI-MS the population of [Au11depp4(Ph3)2Cl2]+ (3421 mz) is dominant other clusters including [Au11depp4(Ph3)2Cl2]+ (3117 mz) are observable No prediction can be made regarding the potential kinetics-controlled reactions during product solution condensation 173

Figure B-5 Proposed mechanism for the formation of three ligand-substituted clusters induced by oxidation on depp174

Figure B-6 Zoomed-in look at Figure 4-5c Other than one oxygen-adduction peaks other small peaks could be negligible in intensity the relative cleanness forms sharp contrast with what is shown in Figure 4-6 174

Figure B-7 Two possible oxidation-induced fragmentation on depp lead to two possible mass assignments to the Au13 derivatives being equivalent in mass and supported by the isotope distribution175

Figure B-8 H-NMR (in CDCl3) of 95 month Audepp showing distinguished high-field and low-filed resonances for alkyl protons and phenyl protons respectively

1

176

Figure B-9 Selected isotope comparison between experimental detection and simulation (in-source tool of MassLynx 30) for all peaks presented in Chapter 4178

Figure B-9 (Cont)Selected isotope comparison between experimental detection and simulation (in-source tool of MassLynx 30) for all peaks presented in Chapter 4179

Figure B-9 (Cont)Selected isotope comparison between experimental detection and simulation (in-source tool of MassLyn 30) for all peaks presented in Chapter 4180

Figure C-1 Negative-MALDI calibration was conducted using Bio-Cal3 which is primary for high mass range calibration for proteomics studies The low mass calibration range is around 800 mz

1

185

xv

List of Tables

Table 2-1 Index results of hard-landing ZrC system along [110] zone axis26

Table 2-2 Index results of soft-landing ZrC system along [361] zone axis28

Table 2-3 Lattice parameter calculation for Zr-Met-Carsrdquo cubic unit shown in Figure 2- 2B31

Table 2-4 Illustration of experimental setup for ablation in a beaker 31

Table 2-5 Radii (handbook) comparison between titanium and zirconium28 32

Table 3-1 Summary of Met-Cars reactivityrsquos studied experimentally in the gas phase 42

Table 3-2 By-product crystals from Case II indicating some organic reaction pathways 54

c Crystals grew from the top polar solvent phase when phase separation was observed55

Table 3-3 Lattice parameters of selected by-products crystals 55

Table 3-4 Crystallographic Data for [Zr O(OH) ]O middot2N( Bu)6 12 6n

457

Table 3-5 Atomic positions of [Zr O(OH) ]O middot2N( Bu)6 12 6n

4 59

Table 3-5 (continued) Atomic positions of [Zr O(OH) ]O middot2N( Bu)6 12 6n

4 60


4 61


4 62

Table 3-6 Selected bond lengths of [Zr O(OH) ]O middot2N( Bu)6 12 6n

4 63

Table 3-7 Summary of related properties of Fischer and Schrock carbenes and carbynes 83

Table 3-8 Summary of all possible ligands combinations The resultant charge status and mass are highlighted in colored areas 85

xvi Table 4-1 Mass assignments for all peaks (major peaks are in bold) in Figure 4-5

to 4-6 showing their close association with tridecagold Species with ldquordquoare ambiguous in the electron status andor surfacevolume ratio due to the complication caused by O which could be associated with phosphorus or bound to Au They are assumed to be associated with lower symmetry structures120

Table 4-2 Crystallographic data of bulk Au with FCC symmetry85 130

Table A-1 Summary of technique limitations on employed instrument (NOVA) compared with recently funded new instrumentation (ldquoDURIPrdquo) which was designed accordingly to overcome these drawbacks 165

Table B-1 Mass assignments for all significant peaks (red and bold) and small oxidize peaks (recognizable in Figure 4-5 and detailed in Figure 7) 177

Table B-2 Summary of Uv-Vis absorption from all recent publications 182

xvii Acknowledgements

ldquoTeach me and I will forget show me and I will remember involve me and I

will understandrdquo I was drawn to join Dr Castlemanrsquos group by reading his vision from

the group website Throughout the years I have developed from a merely good student

with not-so-good memory into an instrumentationalist I have also expanded the

applications of my previous kowledge on crystallography into the facinating field of

cluster based materials thanks to Willrsquos patient guidance and support during this

academic growth I would also like to thank my committee members past and present

Dr Jones Dr Mallouk Dr Sen and Dr Dickey for their insightful teachings support

and understanding through these years It is who you are that makes it not a coincidnece

that much academic guidance was passed on from your students to me with which

problems were solved I know you are not far away in my heart Other faculty members

inside PSU and outside PSU DrMaroncelli Dr Anderson Dr Jin (CMU) and

DrCorbett are cordially appreciated by their mentorings friendships and suggestions in

proofreading my writings

During semesters when funding sources were limited it was my previlidge to

work with a few the wonderful professors in the undergraduate education program they

are DrKeiser DrUcak-Astarlioglu and DrSykes Without their support I could not

have gone through those difficult times Their keen insterest in undergraduate education

has ignited my interest in pursuing similar roles in an acedemic environment

My journey on the Met-cars project was very lonely at the starting point

Throughout years what enabled me to ldquokeep goingrdquo was the great help from many senior

group members in addition to Willrsquos guidance I feel very grateful for your teachings

experience sharing and friendship Of particular mention are Dr Dermota Dr Hydustky

DrBergeron and Dr Kooi And I will never forget you Dr Lyn although you went

onto your next journey quickly so that I missed the opportunity of working with you

your hard work in initiating the instrument and considerate personality have more than

often came into my mind and highly appreciated Castleman group thank you for the all

xviii discussions jokes cookies etc which have been both entertaining and enlightening

Special thanks to David my cloest Lab partners thank you for making me finally

understand that maintaining an instrument needs as much patience as bottle-feeding the

cattle on your farm Pat as well a smart nice and talented young scientist to whom I

feel so approachable for any cross-the-filed discussions I am also lucky to have

extended ldquogroup membersrdquo in DrMallouk Dr Sen and Dr Dickeyrsquos groups thank you

all In particular Qinglei Hongqi Trevor Matt with your offering expertise on TEM I

could have spent more time in the darkrooms

I wanted to be a scientist when I was just a little girl But even with the little

dream I often feel frustrated along the way to pursue it What cheered me up every time

were the many Chinese friends in Chemistry Department Yanyan Weiran Caiyan

Leiliang Hui Jin Yiying Peng and Jian Feng thank you DrQingyi Lu and DrFeng

Gao thanks for your most wonderful friendship and allowing me to use your Lab

hydrothermal setups to try new ideas

Finally I donrsquot know how to present my thanks to my familie enough My father

Yuxiang Gao and my mother Qunying Dong who took much extra effort in bringing up

an often-sick kid ( me) and encouraged me to pursue the advanced degree in science in a

place half globe away Not only those your loving and caring for Alice only made my

current stage possible My husband Dr Ruoxin Li and my life-long friend thank you

for taking me to be your life partner even when I was diagnosed to have potential life-

threatening health problem Finally we grew out Alice the most adorable little creature

Life itself is a miracle giving a life is only a bigger miracle Thank you Alice you are

my miracle

xix Dedicated To

My dear families

Mentors and friends

Chapter 1

Introduction

11 Background Introduction

ldquoFor several millennia mankind has quested for new and better materials from the

earliest days of wood and stone tools to the more recent plastics and alloysrdquo1 It was

alchemists2 who first approached the search for new materials with a scientific

perspective Following the efforts of these ancient scientists chemists as well as

material engineers material physicists are continuing to underpin the mission to acquire

new materials A major school of thought leading to the work presented in this thesis is

the application of bottom-up method to establish the concept of assembling materials

from clusters as the basic building blocks

Cluster defined as ldquoa number of similar things that occur togetherrdquo in Websterrsquos


chemists3 the word cluster means ldquoa group of atoms or molecules formed by interactions

ranging from very weak van der Waals interactions to strong ionic bondsrdquo Differently

from molecules which are made by nature and are stable under ambient conditions

clusters discovered in a laboratory often are metastable Molecules have specific

stoichiometry whereas the clusterrsquos composition can usually be altered atom by atom

Thus clusters can be taken as intrinsically ldquoartificial moleculesrdquo with much more

2 tunabilities in their properties3 It became a very active research area recently especially

after Khanna and Castleman4 5 first suggested that by varying the size and composition

clusters have a chance to expand the periodic table to the 3rd-dimention where clusters

can mimic the chemistry of atoms and may be used as building blocks for new materials

(Figure 1-1)

Figure 1-1 Stable clusters with closed-shell electronic structure have the potential to mimic the properties of atoms in the periodic table to expand it into 3D (from reference6)

Historically and technologically applying mass spectrometry and molecular

beams to study cluster materials began to emerge in the 1950s and quickly became a

subject of considerable interest in the 1970s and 1980s3 The advent of the laser

vaporization technique7 enable researchers to generate clusters from virtually any

refractory elements and various compositions beyond systems of volatile materials

which had been the focus in the beginning For this field clusters are often taken to

symbolize a new embryonic form of matter that is intermediate between atoms and their

bulk counterpart 3 and do not exhibit simple monotonous scaling relation from atom to

3 bulk Cluster studies provide a very unique perspective in gaining insights of these

phenomena in an environment in-between the gas phase and condensed phase

Clusters actually have existed in nature much longer than they are named as can

be exampled by finite particles and dust grains in interstellar media and identified

heterogeneous reactions occurring in the stratosphere3 More commonly noticed is the

major role of clusters in catalysis found in nature8 Nitrogen is converted to ammonia via

the Fe-Mo-S cluster at the heart of the nitrogenase Carbon monoxide is oxidized to

carbon dioxide by carbon monoxide dehydrogenase composed of Fe2 and Ni-Fe clusters

With the discovery of the famous buckminsterfullerene9 and the sequentially

revolutionized advancement in nano-material science cluster-assembled materials

(CAMrsquos)10 11 gradually merged as new and appealing subjects of research interest

Symmetries seem to be favored by clusters especially those with material

application potentials from C60 (a covalently bonded cluster in Figure 1-2)

Metallocarbohedrene12 13 (a compound cluster and will be referred to as ldquoMet-Carrdquo for

Figure 1-2 C60 with Ih symmetry (from reference15)

short) Au2014 (a metal scluster) to Al13

- anionic cluster16 These distinguished geometric

structural features are closely related to their electronic structures While there is no

4 generalization of a uniform model to explain the evolution of cluster electronic structures

there are generally two models being discussed mostly and largely capable of being

consistent with the experimental discoveries The polyhedral skeletal electron pair theory

or Wades electron counting rules17 predict trends in the stability and structures of clusters

bound with small organic ligands while the Jellium11 model is often used to explain the

stability of naked metal clusters Ligand stabilized metal-clusters are prominently found

with refractory metals18 19 These metal centers with large d-orbitals form stable clusters

because of the favorable overlap of valence orbitals Thus metals with a low oxidation

state and therefore small effective charges tend to form stable clusters17 The Jellium

model11 is based on the assumption of spherical and uniform positive charge density and

the valence electrons of the cluster fill the energy levels in accordance with the Pauli

principle20 Each time an electronic shell is full the corresponding cluster should exhibit

pronounced stability with magic electron counts of 2 8 20 40hellipMore recent self-

consistent models take the Jahn-Teller distortion effect into account and the model seems

to be able to predict the stability of virtually all structures to more refined extent21

Bearing many unique structural and electronic features clusters find applications

in multidisciplinary areas3 For example in the petroleum industry due to its large

surface-to-volume ratio the unique behavior of these low-dimensional species composed

of noble metal clusters have been extensively studied for catalytic applications either as

free clusters22 or as supported media23 where many important reactions can be catalyzed

such as CO conversion to CO2 Clusters can also be used as magnetic materials (such as

5 sensors24 and memory devices25) luminescent materials (such as optoelectronics26

tagging agent24) and high energy density16 and H2 storage media27

12 Motivation

It has been commented that Met-Cars are so far the only other molecular cluster in

addition to C603 with even more tunabilities with the widely variable compositions and

richer chemical catalytic electronic and magnetic properties owing to the introduction of

transition metals

The Ti-Met-Car with stoichiometry Ti8C12 was the first discovered member of this

family12 during the course of studying the dehydrogenation reactions of hydrocarbons by

titanium atoms ions and cluster in the similar way as the C60+

was discovered by mass

spectrometry It showed up as a ldquomagic numberrdquo peak against the overall distribution

(Figure 1-3) The composition was confirmed with ND3 titration to show 8 metal atoms

Figure 1-3 Mass distribution of TimCn+ clusters generated from the reaction s of titanium

with CH4 ( from reference12)

6 are exposed to the surface with similar coordination A pentagonal dodecahedral

structure of Th point group symmetry was proposed to explain its unusual stabilities

Soon after that a wide range of other members of Met-Car family were observed

including Zr Hf V Nb13 28 29 in our group as well as subsequently Cr Fe Mo

containing species by Duncan30 Binary Met-Cars composed of the combination of two

of the above metals in the constituent have also be reported31-33 Furthermore other

metals31 32 34 including Y Ta W Si (as an exception being a non-metal dopant into a

metal position) which do not commonly form the pure Met-Car can be doped into the

metal position of Ti-Met-Cars as proved experimentally Other non-metal dopants were

largely tested by ab initio quantum mechanical calculation a series of hypothetical (Bl Nm

Sin)C12 (m + n + l = 8 ) clusters35 were identified by Domingos to have high stabilities

Diversity in composition of Met-Car families has further potentially expanded onto the C

position based on some theoretical calculations showing the stabilities of Sc8B1236 and

Co12B837 All of these findings together strongly indicate the prospective of Met-Cars as

the basic tunable building blocks for new assembled materials

It has been both experimentally12 13 28 and theoretically38 suggested that the

principle bonding motif of Mer-Cars is M-C2 bound through both σ and π interactions

indicatively labeled as [M8(C2)6] by Dance39 Although Th symmetry could well account

for the original ND3 titration results12 many other structures39 40 with lower symmetry

(Td D2d D3d C3v C2v) (Figure 1- 4) have been suggested to have lower surface potentials

and thus be more stable isomers Among them Td symmetry has been mostly selected to

7

Figure 1-4 The optimized geometries of the Ti8C12 with various symmetries (from reference40)

model the electronic structures and the related chemical properties of Met-Cars as a

reasonable approximation for the symmetry unless there are necessities involving lower

symmetries41 Therefore the author will mainly follow the same approximation fashion

for the rest of the discussions in this thesis

In the Met-Cars of Td as suggested by the well-established organometallic

chemical bonding principles17 itrsquos well accepted that for the 24 bonds in the T symmetry

there are 12 M-C σ-bonds (in Figure1-5 right) and 12 Ti-C2 π-bonds42 43 (in Figure1-5

left) Such M-C2 bonding units were first suggested by Castleman et al12 28 and further

supported by Duncanrsquos photodissociation experiments44 on TiZr-Met-Car which

8

Figure 1-5 Two views of the Td structures of Met-Car (from reference45) with emphasis on M-C2 π bonds and M-C2 σ bonds (spheres in light Ti in dark C)

indicated the elimination of M-C2 as one of the decomposition channels as well the IR

studies46 47 by Meijer and Helden in Netherlands showing only one C-C stretch vibration

at ~1400 cm-1 and corresponding to the symmetry and the equivalent bonding

environments for all C=C units

The potential of using Met-Cars as the building blocks for larger assembled

materials not only finds basis from their diversity of composition and unique stabilities

but research has shown that they can form into multicages48 49 (up to 4 cages) by sharing

pentagonal faces or dimerize through C-M four member rings40 As shown in Figure 1-6

Figure 1-6 Proposed Met-Car cage (Th) and double- triple- and quadruple-cage the metal atoms are represented in purple and the carbon atoms are represented in green (from reference49)

9 Proposed possible structures from a unusual structural growth pattern observed in ZrmCn

+

mss spectra including the region beyond the mass of Zr8C12+ masses bearing the magic

numbers of double cage Zr13C22+ triple cage Zr14C2123

+ and quadruple cage Zr18C29+

were rigorously consistent with expectations for the formation of multicage structures

Shown in Figure 1-7 a calculation done by Pederson showed the possibility of two

Figure 1-7 Various of dimmer structures (from reference40)

Ti-Met-Cars coalescing to form a stable dimer in which both the individual Met-Cars

retain their identity They both form a basis for future studies on Met-Car based

molecular solids at least regarding the growth into low-dimensional structures Indeed

an interesting simulation has proposed new ldquohybridrdquo nanostructures50 consisting of linear

chains of (Sc Ti V)-Met-Cars located inside single-walled carbon or boron-nitrogen

nanotubes This type of hybrid material is expected to have tunable electronic properties

attainable by chemically varying the composition of the Met-Cars

Some of Met-Carsrsquo exciting properties have been demonstrated both

experimentally and theoretically such as their good catalytic properties for the oxidation

10 of CO S and SO251-55 delayed ionization behavior56 57 and low ionization potential33

Some of them are drawing more attention through theoretical calculations such as the

and superconductivities58 (Figure 1-8) and hydrogen storage properties27 59 (Figure 1-9)

Figure 1-8 Calculated B8C12 of Met-Car stoichiometry in solid FCC phase shown to be metallic and with strong electron-phonon coupling and high Tc superconductive behaviors (from reference60)

Determining the exact structure of Met-Cars becomes the key-issue to rationalize

these properties and to access their unique functions chemically Attempts made to

analyze the deposited Met-Car on TEM grids and to use ligand-protection method to

capture Met-Cars in liquid phase are presented in details throughout the thesis with such

motivations

11

Figure 1-9 Illustration of the potential hydrogen storage application of Met-Cars to achieve up to 56 wt H capacity approaching the minimum requirement of 6 wt for practical applications (from reference27)

There are other closely related clusters of stoichiometry of Ti14C13 and Ti13C22

being discovered parallelly in many experiments under similar conditions as in the

discoveries of Met-Cars and have been termed as ldquometal carbon nonacrystalsrdquo since such

species are mostly well-studied in anion forms These are not the focus of the subject of

this thesis and interested readers are referred to the recent report61 and cited references

therein

13 Thesis Organization

Following the introductory chapter Chapter 2 reports preliminary results of

depositing mass-gated Zr-Met-Cars on TEM grids and the structural investigation via

electron diffraction technique62 The production of Met-Cars is conducted with the direct

laser vaporization (DLV) of metalgraphite composite pellets After being mass gated in

a reflectron equipped time-of-flight mass spectrometer (TOF-MS) and deposited onto

12 TEM grids the resultant specimens can be loaded onto a high-resolution TEM for

investigation via electron diffraction Soft-landing of mass selected clusters has been

shown to be a successful approach to obtain structural information on Zr-Met-Car cluster-

assembled materials collected from the gas phase TEM images indicate a large FCC

lattice with parameters comparable with FCC-C60 and are attributed to the formation of

Zr-Met-Cars cluster-assembled material (CAMrsquos)

Attempts of using the solvothermal synthesis method to prepare Met-Cars clusters

and the preliminary results are presented in Chapter 3 It came to my realization that

due to the limited cluster ion intensity per unit time and the complicated interactions

between the deposit and the substrate little control could be made over the cluster

nanocrystal formation Stabilization of metal-carbon clusters through surface ligation in

the liquid phase should offer an opportunity to isolate Met-Car-like structural motifs in

the liquid phase One successful experiment generated a product in the form of a single

crystal and the structure is resolved through single crystal X-ray diffraction showing a

[OZr6(OH)12O6 ] cluster anion63 Itrsquos expected that the endeavor along this direction will

lead to the liquid-phase synthesis of at least Met-Car analogous metallo-compounds

My collaboration with DrBergeron from NIST on Monolayer Protected Gold

Clusters (Au-MPC) is based on this plan and is presented in Chapter 4 Studying surface

protected clusters became my interest because what could be learned there is anticipated

to help future designing of synthesis methods towards the isolation of Met-Cars from

liquid phase We studied the ligand-core interactions between Aun (n=10 11 12) cluster

cores and the bi-dentate diphosphino ligand shells through mainly electrospray ionization

13 characterization64 Very interestingly undeca- dodeca- and trideca-gold clusters

protected by depp and halogen ligands ie[Au11-13(depp)4Cl2-4]+ are found to be all

predominant and persist in solution for months while they gradually self-grow into

monomial tridecagold clusters series65 Such self-growth behaviors and the resultant

Self-Assembled Arrays (SAA) observations from TEM are correlated by icosahedra-

close-packing modes of clusters following ldquomagic numbersrdquo rules

Chapter 5 concludes these studies As the exploration of these cluster-assembled

materials is only just beginning the gas phase deposition and ligand protected clusters

both represent the very promising methodologies to bringing the gaseous clusters into

condensed phases and hope to demonstrate some important yet predicted impacts on

nanomaterial advancement in the near future

14 References

1 Toleno B J Metallocarbohedrenes the quest for new materials PhD Thesis

PSU Penn State University University Park 1998

2 Byko M Converting trivia to cash Alchemists win the first TMS Materials

Bowl 2007 Vol 59 p 64-64

3 Castleman A W Jr and Jena P PNAS 2006 103(28) 10552

4 Khanna S N Jena P Physical Review Letters 1992 69 (11) 1664-1667

5 Castleman A W Jr International Journal of Mass Spectrometry and Ion

Processes 1992 118 167-189

6 Abraham S A Extending the Periodic Table of Elements Introducing multiple

valence superatoms VCU News Center 112206 2006

14 7 Dietz T G Duncan M A Powers D E Smalley R E Journal of Chemical

Physics 1981 74 (11) 6511-6512

8 Fish R H Jaouen G Organometallics 2003 22 (11) 2166-2177

9 Kroto H W Heath J R Obrien S C Curl R F Smalley R E Nature

1985 318 (6042) 162-163

10 Jena P Khanna S N Rao B K Surface Review and Letters 1996 3 (1) 993-

999

11 Gronbeck H Rosen A Surface Review and Letters 1996 3 (1) 1001-1006

12 Guo B C Kerns K P Castleman A W Jr Science 1992 255 (5050) 1411-

1413

13 Guo B C Wei S Purnell J Buzza S Castleman A W Jr Science 1992

256 (5056) 515-516

14 Li J Li X Zhai H J Wang L S Science 2003 299 (5608) 864-867

15 wwwindividualutorontocapeterschool

16 Bergeron D E Castleman A W Jr Morisato T Khanna S N Science

2004 304 (5667) 84-87

17 Cotton F A Wilkinson G Murillo C A Bochmann M Advanced Inorganic

Chemistry 6th ed John Wileyamp Sons Inc New York 1999

18 Schmid G Clusters and Colloids From Theory to Applications Weinheim

New York 1994

19 Meiwes-Broer K Metal Clusters at Surfaces Strucure Quantum Properties

Physical Chemistry Sringer Berlin 2000

20 Pauli W Science 1946 103 (2669) 213-215

21 Deheer W A Reviews of Modern Physics 1993 65 (3) 611-676

22 Kimble M L Moore N A Castleman A W Burgel C Mitric R Bonacic-

Koutecky V European Physical Journal D 2007 43 (1-3) 205-208

23 Arenz M Landman U Heiz U Chemphyschem 2006 7 (9) 1871-1879

24 Qiang Y Antony J Sharma A Nutting J Sikes D Meyer D Journal of

Nanoparticle Research 2006 8 (3-4) 489-496

15 25 Lau C N Stewart D R Williams R S Bockrath M Nano Letters 2004 4

(4) 569-572

26 Borsella E Cattaruzza E De Marchi G Gonella F Mattei G Mazzoldi P

Quaranta A Battaglin G Polloni R Journal of Non-Crystalline Solids 1999 245

122-128

27 Akman N Durgun E Yildirim T Ciraci S Journal of Physics-Condensed

Matter 2006 18 (41) 9509-9517

28 Wei S Guo B C Purnell J Buzza S Castleman A W Jr Journal of

Physical Chemistry 1992 96 (11) 4166-4168

29 Purnell J Wei S Castleman A W Chemical Physics Letters 1994 229 (1-2)

105-110

30 Pilgrim J S Duncan M A Journal of the American Chemical Society 1993

115 (15) 6958-6961

31 Cartier S F Chen Z Y Walder G J Sleppy C R Castleman A W

Science 1993 260 (5105) 195-196

32 May B D Kooi S E Toleno B J Castleman A W Jr Journal of Chemical

Physics 1997 106 (6) 2231-2238

33 Sakurai H Castleman A W Jr Journal of Physical Chemistry A 1998 102

(51) 10486-10492

34 Deng H T Guo B C Kerns KP and Castleman A W Jr International

Journal of Mass Spectrometry and Ion Processes 1994 138 275-281

35 Domingos H S Modelling and Simulation in Materials Science and

Engineering 2006 14 (4) 637-646

36 Clouthier S C Collinson S K Kay W W Molecular Microbiology 1994 12

(6) 893-901

37 He C N Zhao N Q Shi C S Du X W Li J J Journal of Alloys and

Compounds 2007 433 (1-2) 79-83

38 Rohmer M M Benard M Poblet J M Chemical Reviews 2000 100 (2)

495-542

16 39 Dance I W E a H H Chem Eur J 2002 8 (15) 3497-3511

40 Baruah T Pederson M R Physical Review B 2002 66 (24)

41 Sobhy M A Castleman A W Jr Sofo J O Journal of Chemical Physics

2005 123 (15)

42 Krantzman K D Kingsbury D B Garrison B J Applied Surface Science

2006 252 (19) 6463-6465

43 Martinez J I Castro A Rubio A Poblet J M Alonso J A Chemical

Physics Letters 2004 398 (4-6) 292-296


115 (10) 4395-4396

45 Dance I Wenger E Harris H Chemistry-a European Journal 2002 8 (15)

3497-3511

46 Heijnsbergen D Helden G Duncan M A Roij A J A Meijer G Physical

Review Letters 1999 83 (24) 4983-4986

47 Heijnsbergen D Duncan M A Meijer G von Helden G Chemical Physics

Letters 2001 349 (3-4) 220-226

48 Wei S Castleman A W Jr Chemical Physics Letters 1994 227 (3) 305-311

49 Wei S Guo B C Purnell J Buzza S Castleman A W Jr Science 1992

256 (5058) 818-820

50 Sofronov A A Ivanovskaya V V Makurin Y N Ivanovskii A L

Chemical Physics Letters 2002 351 (1-2) 35-41

51 Lightstone J M Mann H A Wu M Johnson P M White M G Journal of

Physical Chemistry B 2003 107 (38) 10359-10366

52 Lightstone J M Patterson M J Liu P White M G Journal of Physical

Chemistry A 2006 110 (10) 3505-3513

53 Liu P Rodriguez J A Muckerman J T Journal of Molecular Catalysis a-

Chemical 2005 239 (1-2) 116-124

54 Liu P Rodriguez J A Muckerman J T Journal of Physical Chemistry B

2004 108 (49) 18796-18798

17 55 Liu P Rodriguez J A Journal of Chemical Physics 2003 119 (20) 10895-

10903

56 Davis K M Peppernick S J Castleman A W Jr Journal of Chemical

Physics 2006 124 (16)

57 Stairs J Calculations of the Geometrical Sizes Met-Cars in Th

58 Domingos H S Bristowe P D Journal of Physics-Condensed Matter 2003

15 (25) 4341-4348

59 Zhao Y F Dillon A C Kim Y H Heben M J Zhang S B Chemical

Physics Letters 2006 425 (4-6) 273-277

60 Domingos H S JPhysCondensed Matter 2005 17 2571

61 Patzschke M Sundholm D J Phys Chem B 2005 109 12503-12508

62 Gao L Lyn M E Bergeron D E Castleman A W Jr International Journal

of Mass Spectrometry 2003 229 (1-2) 11-17

63 Gao L Castleman A W Jr Ugrinov A Liquid Phase Synthesis of

Hexanuclear Zr hydroxy-oxo-clusters In 2008

64 Golightly J S G L Castleman A W Jr Bergeron D E Hudgens J W

Magyar R J Gonzalez C A Journal of Physical Chemistry C 2007 111 (40) 14625-

14627

65 Gao L Bergeron D E Castleman A W Jr A Spontaneous Growth Behavior

of Phosphino Ligands Protected Aun(n=11-13)-MPCs and the Possible Correlation with

Self-Assembled Arrays In 2008

18

Chapter 2

Mass Deposition and Preliminary Structural Study of Met-Cars via Transmission

Electron Microscopy (TEM)

21 Abstract

The discovery of Met-Cars has drawn worldwide interest and has been actively





method involving the deposition of mass-gated species and the followed structural







specimens can be loaded onto high-resolution TEM for investigation via electron

diffraction

19 In conclusion soft-landing of mass selected clusters has been proven as a





clusters From this initial study the promising opportunity to study other Met-Cars

species and more cluster-based materials is shown

20

22 Introduction

As reviewed in Chapter 1 despite extensive theoretical and experimental efforts

the structural determination of Met-Cars remains a central unresolved question In

general structural determination via analysis of diffraction measurements is most

desirable and still holds as the most direct evidence of the spatial arrangement at the

atomic level1 2 Parks et al have utilized the Trapped Ion electron Diffraction (TIED)

technique1 2 to probe small metal cluster structures trapped and collisionally relaxed in a

Paul trap However in addition to the complicated instrumentation successes have been

mainly in noble metal cluster systems due to the needed stable cluster intensity and no

compound clusters have been studied Other structural investigations were made mainly

from theoretical calculations3 and indirect experimental studies such as ion mobility4 and

Photoelectron Spectroscopy (PES) measurements5 6 providing either rough structural

classification as being a cage instead of other motifs or pointing out the Td symmetry of

free Met-Car clusters in gas phase From the material application point of view

formation of cluster-assembled solids7 would be desired and should in principle enable

diffraction techniques to probe the structures of the individual cluster units as well as the

packing motifs

Soon after the discovery of Met-Cars8 it has been demonstrated the ability to

produce Met-Cars in the solid state was determined9 The unsuccessful search for a

solvent capable of isolating the clusters has impeded progress in characterizing the

21 material in the condensed state and in contrast to the bulk carbides10 11 these potential

new nanoscale materials are under-explored12

Most of our knowledge about the properties of Met-Cars is based on gas phase

studies (see Chapter 13) The individual Met-Car differs from the rock-salt structure of

the conventional carbide and grows with an independent cage structure under appropriate

conditions13-16 Structures with a variety of bonding motifs have been considered

theoretically to account for the Met-Carsrsquo stability with experiments and theory tending

to support a Td structure rather than one with the originally proposed Th symmetry6-8 (for

extensive review of experimental and theoretical Met-Car studies see reference17) Avery

recent calculation has established that the C3v structure has the lowest energy among the

variants considered18

In view of difficulties in finding a suitable solvent for isolating Met-Cars an

alternative method involving the deposition of mass gated species was employed in the

present study19 Foregoing questions of the stability of Met-Cars when exposed to air the

experiments20 reported herein were conducted to produce Met-Cars from the direct laser

vaporization (DLV) of metalgraphite composite electrodes After being mass gated

and deposited onto carbon-covered transmission electron microscopy grids the resultant

specimens were loaded onto the high-resolution transmission electron microscope

(HRTEM) for electron diffraction studies Preliminary results of the structural

investigation of deposited Met-Cars via the diffraction analysis are reported herein

22 23 Experimental

The deposition experiments were conducted by DrLyn and detailed description

has been reported20 What is related to the results reported herein is given briefly below

with the schematic of the experimental configuration shown in Figure 2-1

The Zr-Met-Cars were obtained from a home-built time-of-flight mass

spectrometer (Figure 2-1A) equipped with the DLV cluster generation source using the

second harmonic 532nm (with duration of ~7ns) from a GCR-3 NdYAG laser operated

at 10 Hz After a confirmative observation of the desired cluster signal (at 872 amu for

Zr-Met-Carsrsquo mass center) was made the distribution of cluster species was mass gated

at the time point when the Zr-Met-Cars were passing the deflector plates20 (and see

Figure 2-1B) The followed deposition of the gated species onto TEM grids were

conducted under either hard (with ~228 keV20 landing energy) or soft (with lt 20 eV20

landing energy) conditions where in the latter a reflectron was employed to decrease the

kinetic energies of the impacting cluster ions ( Figure 2-1C)

23

Figure 2-1 Schematic of the experiment setup a)overall configuration b)hard landing c) soft-landing deposition arrangements Note that during the soft-landing deposition of the mass gated packets the species are deposited with a small distribution of energies arising from the spatial distribution in the extraction region of the time-of-flight (slightly modified from reference20 with permission)

24 The deposition substrate ndashlacey carbon covered Cu TEM grids (Electron

Microscopy Sciences) ndashwas chosen because the carbon layer is amorphous allowing for

facile identification of deposited crystalline species as well as minimizing the potential

for any epitaxial growth processes The HRTEM examination was conducted on JEOL

model JEM 200CX operated at 200kV accelerating voltage The Selected-Area

Diffraction Pattern (SADP) was recorded with the camera of 40 cm

It is of mention that all species are exposed to air for short periods of time during

the transfer from the mass spectrometer to the electron microscope While Met-Cars

have been found to be air sensitive under energetic collision conditions they have been

found to be stable for short exposure to air9 21 22 Also as discussed below theoretical

calculations suggest that the Met-Cars bond into a stable cubic structure in the condensed

state While elemental analysis indicated the presence of some oxygen on the grids it

should be noted that upon careful analysis of the electron diffraction images none of the

diffraction features of the deposits described here were found to exhibit the crystalline

characteristics of bulk oxides23

24 Results

Under the hard-landing conditions TEM images of nanocrystals ~2 Aring in diameter

could be seen from the deposition of ZrC species mass gated at Zr8C12 (Figure 2-2A)

No clear diffraction pattern (DP) could be obtained Without DP it is hard to

quantitatively estimate the representative quality of the selected nanocrystals versus all

25 nanocrystalline features on the grid surface The features selected for detailed study were

chosen for their amenability to fast Fourier transformation (FFT) shown in Figure 2-2B

Similar patterns were observed in some other spots in the images Implementing the two

dimensional FFT (Program Matlab from Mathsoft) analysis of the images shown in

Figure 2-2A revealed d-spacings (Table 2-1) that correspond to the conventional rock-

salt zirconium carbide24 A limited number of diffraction spots (six at most) were

extracted These are indexed as belonging to two family planes (111)(111)(111)(111)

and (002)(00 2 ) associated with the [110] zone axis in a FCC lattice

Figure 2-2 The subparts (i) (ii) and (iii) indicate images taken from different area in the TEM specimen (A) HRTEM images of ZrC deposits mass gated at Zr8C12 Thespecies were deposited with ~228 kV of kinetic energy (B) Two-dimensional fast Fourier transformations (FFT) of the images The sketches show the d-spacings obtained from the FFT images that correspond to the above images respectively Errorsassociated with the FFT are evident from the asymmetry of the d-spacings shown in the sketches (modified from reference20 with indexing analysis results)

26 As seen in the sketches (Figure 2-2B above) for these FFT results the d-spacings

are in good agreement with those reported in Table 2-1 (below) which are obtained by

calculation using Equation (1) and are very close to the literature values with less than

1 relative errors

i hkl 3

Ri (mm) (Reciprocal

Vector Mode) Comparison

Di (Aring) (D-spacing value)

θri-r12 (Inter-

planar angle)

DiD1 (Spacing

Ratio)

Exp Value 295(11) 709ordm 1 Ref Value1 2709 7052ordm 1 1 111 341(13)

Relative error 88 054 0 Exp Value 252(6) 5435ordm 1168 Ref Value1 2346 5474ordm 1155 2 200 398(9)

Relative error 75 -071 054

1 ZrC powder diffraction data24 2 θri-r1 = cos-1 [ (hi ki li) (h1 k1 l1) (hi ki li)12 (h1 k1 l1)12

] 3 The corresponding diffraction pattern obtained from computer simulation (not presented here) is in good agreement with the experimental pattern Table 2-1 Index results of hard-landing ZrC system along [110] zone axis

Following tests under hard-landing conditions a soft landing experiment was

conducted for the ZrC system using the arrangement in Figure 2-1C Soft-landed ZrC

species that were mass gated at Zr8C12 are shown in Figure 2-3A A comprehensive set

of diffraction spots with well-defined positions were indexed yielding three sets of

family planes (113)( 113 ) (3 13)(31 3 ) and ( 4 20)(4 2 0) along with an unusually high

order zone axis of [361] in a FCC lattice

27

Figure 2-3 HR-TEM images of soft-landed ZrC species mass gated at Zr8C12 (A) and corresponding diffraction pattern (B) (scale bar 15 nm) (modified from reference20 with indexing analysis results)

(A)

(B)

+ [361]

(-313)

(-420)

(-11-3)

(3-1-3)

(4-20)

(1-13)

In Table 2-2 (below) it is seen that the relative ratios between d-spacings deviate

from theoretical values by only 21 at most This indicates a great degree of certainty

in indexing the diffraction spots Three d-spacings 4666 3746 and 3440 Aring could be

determined from the diffraction pattern (Figure 2-3B) obtained from a region in the

image shown in Figure 2-3A These calculated d-spacings (Table 2-2) do not correspond

to those of either ZrC or ZrO2 The average value of the lattice parameter of the cubic

unit cell is calculated to be 1534 Aring

28

i hkl 2

Ri (mm) (Reciprocal



θri-r11 (Inter-

planar angle)

DiD1 (Spacing

Ratio) Exp Value 467(11) 680ordm 1 Ref Value NA 6977ordm 1 1 311 215(5)

Relative error NA 054 0 Exp Value 348(6) 680ordm 134 Ref Value NA 6977ordm 1314 2 331 289(5)

Relative error NA 25 21 Exp Value 344(6) 660 136 Ref Value NA 6614 1348 3 420 298(5)

Relative error NA 021 06

1 θri-r1 = cos-1 [ (hi ki li) (h1 k1 l1) (hi ki li)12 (h1 k1 l1)12 ]

2 The corresponding diffraction pattern obtained from computer simulation (not presented here) is in good agreement with the experimental pattern Table 2-2 Index results of soft-landing ZrC system along [361] zone axis

25 Discussion

All experimental d-spacings presented in Tables 2-1 2-2 were calculated based

on the Bragg Diffraction equation25 with the first-order approximation

d cong λLr (1)

29 where the λ L and r represnt the wavelength of the electron beam (00251Aring25 with

accelerating voltage of 200kV) the camera length (40cm see Experimental section) and

the measured reciprocal distances25 in the diffraction patterns respectively

On the basis of the FFT results we conclude that only the metal carbide species

ZrC with a much simpler structure and smaller lattice parameter than expected for Met-

Cars are dominant in the TEM specimen produced under hard-landing conditions The

possibility of impact-stimulated formation of surface alloys as the mechanism responsible

for the observed carbide bulk structure cannot be excluded24 26 In fact it is considered

likely that the clustersrsquo collision energy could be transformed simultaneously into

embedding energy andor fragmentation energy allowing the deposits to re-construct

freely through interactions with the substrate Evidently under these conditions the

deposited Met-Cars and larger Zr-C species underwent atomic rearrangements to produce

the conventional metal carbide ZrC instead of assemblies of Met-Cars or larger clusters

Significantly the image acquired under soft landing conditions was quite

different Indeed the ZrC deposition revealed the presence of a species that may be Zr-

Met-Cars (or possibly a composite with larger cluster assemblies) displaying a

substantially larger lattice parameters namely 1534 Aring than the cubic ZrC24 with the

same FCC type packing mode This value provides encouraging evidence for cluster

assembly which is further supported by preliminary calculation27 based plane-wave

pseudopotential GGA methods as illustrated below

30

Figure 2-4 Courtesy contribution and cited with permission27 theoretical calculation supports the proposed FCC packing for Ti-Met-Cars (in Td symmetry) solids

In these unpublished preliminary results Zhao27 found that the FCC phase has the

lowest energy and the equilibrium FCC lattice constant is ~71Aring ldquoBoth the cell length

and the cell angle (60 degree) are stable upon fully relaxation of all the cell parametersrdquo

Thus the deduced structure of the Zr-Met-Cars solids in FCC lattice was assigned with

confidence

However it is important to note that whether through discharging or through

impact-induced structural rearrangement it is possible that geometrical perturbations of

the Met-Car structure might occur As the structures for neutral and charged Met-Cars

are not completely characterized any such perturbations would be unobservable in the

present experiments

31 We also note that there are moderately large differences between this value and

those of Ti Met-Cars deduced from a theoretical calculation27 (see Table 2-3 and 2-4

below)

d (Aring) (d-spacing) hkl (Muumlller

indices) (h2 + k2 + l2)12 a (Aring)1 (lattice constant)

467(11) 311 (11) frac12 1548(36) 348(6) 331 (19) frac12 1515(26) 344(6) 420 (20) frac12 1538(27)

Average a (Aring) 1534(30) r (Aring)2 (Size of packing ball) 542(10)

1 The lattice constant a is calculated based on the formula a = dhkl (h2 + k2 + l2)12

2 The size of the packing unit is calculated based on the lsquocloset hard-sphere modelrsquo and the corresponding geometrical relationship between a and r 4r = (2)12 a Table 2-3 Lattice parameter calculation for Zr-Met-Carsrdquo cubic unit shown in Figure 2- 2B

Spacing

Methods Radius of Zr-Met-Cars (Aring)

Radius of Ti-Met-Cars (Aring)

Radii Ratio

experiment (lattice parameter a)1 542 (1534) NA theoretical2 (lattice parameter a) NA 355 (1004)

15

1 Calculated based on the relationship between a and r 4r = (2)12 a 2 From27 Table 2-4 Illustration of experimental setup for ablation in a beaker

32 These differences likely arise at least partially because of the consideration

discussed as follows Zirconium is located one row below titanium in group IV in the

periodic table with larger radii in both the 0 and +4 oxidation states than those of

titanium (Table 2-5) When Zr and Ti participate in constructing a Met-Car structure

similar trends between the two structural parameters for the corresponding Met-Cars

would be anticipated This trend is still significantly smaller than those shown in Table

2-4 A better understanding of the differences brought about by the replacement of Ti by

Zr must await structural calculations specific for the Zr-Met-Cars solid lattice Whether

or not there should be a necessarily linear relationship of the radii between naked atoms

or ions and Met-Cars is still an open question

Oxidation State Radius of Ti (Aring) Radius of Zr (Aring) Radii Ratio

+4 068 080 12 0 149 160 11

Table 2-5 Radii28 (handbook) comparison between titanium and zirconium

Before drawing the final conclusion for the studies presented herein we wish to

point out some limitations in our study of using TEM to derive structural information on

Met-Cars Previous studies have concluded that Met-Cars usually behave like giant

atoms Inspired by this view we assume that the cluster-assembled species in the TEM

33 specimen examined in scatters the oncoming electron beam as a hard-sphere This

assumption serves to explain why our current TEM images alone cannot provide fine

structure information regarding the arrangements of the individual metal and carbon

atoms

The second limitation lies in the intrinsic accuracy limit of TEM itself Even with

high quality data usually TEM results alone cannot provide enough precision to fully

characterize material structures In most cases TEM investigations should be used only

as one complementary technique along with other measurements such as X-ray

diffraction and extended X-ray edge fine-structure analysis to provide additional

information which could either support or refute the initial tentative characterization

Therefore with only limited d-spacing values from the TEM image analysis the data

presented in this paper should only be taken as a preliminary study towards our ultimate

goal characterizing deposited Met-Cars and their assemblies

26 Conclusion

The presented results indicate that under hard-landing conditions zirconium Met-

Cars and larger metal-carbon species undergo atomic rearrangement to produce the

respective metal carbide while a significantly larger species packed in a FCC structure

with a lattice parameter of 1534 Aring was found under soft-landing conditions We cannot

specifically ensure the deposits are comprised only of Met-Cars with the current

34 experimental set up however the large dimensions of the FCC lattice suggests cluster

assembly

The regular lattice of the deposited material is indicative of the assembly of

uniform particles The statistical distribution of clusters larger than Met-Cars seems an

unlikely source for the building blocks of such a regular assembly In addition the

clusters higher in mass than the Met-Cars are thought to have essentially nanocrystalline

carbide structures Intuitively the coalescence of such clusters would yield features with

lattice characteristics resembling bulk carbides No such features were observed in the

present study and so it is tentatively suggested that the assemblies described here are

likely composed mainly of Met-Cars Further investigations with a narrower mass

selection window will eventually allow direct comparison of carbide cluster and Met-Car

deposit characteristics

The results obtained thus far provide two prospects First the hardsoft-landing

deposition method builds a bridge between the DLV coupled mass spectrometry and

TEM as a tool for structural investigation This combination yields a very valuable route

to study some novel clusters that are initially observed in the gas phase and can neither be

immediately synthesized nor isolated in the solid state in relatively large quantities

Secondly the experimental conditions used in this preliminary investigation lay the

foundation for a new platform for further studies aiming at producing Met-Car-based

materials in macroscopic quantities and gaining insights into the interaction and

arrangements of nanometric caged carbide species (Met-Cars) on surfaces

35 27 Acknowledgements

The authors would like to thank Professor Elizabeth Dickey of the Department of

Materials Science and Engineering at Pennsylvania State University for the enlightening

discussions regarding TEM image indexing and Jinguo Wang of the Materials Research

Institute at the Pennsylvania State University for assistance in TEM imaging Finally we

gratefully acknowledge financial support from the AFOSR Grant No F49620-01-1-0122

for the soft-landing studies and the NSF-NIRT Grant NoDMR01-03585 for the hard-

landing investigations

28 References

1 Xing X P Danell R M Garzon I L Michaelian K Blom M N Burns M

M Parks J H Physical Review B 2005 72 (8)

2 Xing X P Yoon B Landman U Parks J H Physical Review B 2006 74

(16)

3 Gao L Chapter 1 of the PhD Thesis In 2008

4 Lee S H Gotts N G Vonhelden G Bowers M T Science 1995 267

(5200) 999-1001

5 Wang L S Li S Wu H B Journal of Physical Chemistry 1996 100 (50)

19211-19214

6 Li S Wu H B Wang L S Journal of the American Chemical Society 1997

119 (32) 7417-7422

36 7 Khanna S N Jena P Physical Review Letters 1992 69 (11) 1664-1667


1413

9 Cartier S F Chen Z Y Walder G J Sleppy C R Castleman A W Jr

Science 1993 260 (5105) 195-196

10 Oyama T Encyclopedia of Chem Tech 4 ed Wiley New York 1991 p 1890-

1957

11 Pierson H O Handbook of refractory carbides and nitrides properties

characteristics processing and applications Park Ridge NJ 1996

12 Weiss P S McCarty G S Keating C D Fuchs D J Abstracts of Papers of

the American Chemical Society 1999 218 U426-U426


(42) 7695-7698





256 (5058) 818-820


495-542




20 Lyn M E Progress Towards Studying Metallocarbohedrenes in The Condensed

Phase Pennsylvania State University University Park 2002

21 Guo B C Kerns K P Castleman A W Jr Journal of the American Chemical

Society 1993 115 (16) 7415-7418

22 Deng H T Kerns K P Bell R C Castleman A W Jr International Journal

of Mass Spectrometry 1997 167 615-625

37 23 File 27-997 20-684 powder Diffraction File International Centre for

Diffraction Data 1601 Park Lane Swarthmore PA 2006

24 35784 Powder Diffraction File International Centre for Diffraction Data

PA 2006

25 Williams D B Carter C B Transmission Electron Microscopy Springger

Science New York N Y 10013 1996

26 Pauwels B Van Tendeloo G Bouwen W Kuhn L T Lievens P Lei H

Hou M Physical Review B 2000 62 (15) 10383-10393

27 Zhao J J Post Doctor University of North Carolina 2002 current contact

information zhaojjdluteducn

28 Handbook of Chemistry and Physics 36th Ed Chemical Rubber Publishing Co

1954-1955

38

Chapter 3

Application of Solvothermal Synthesis to IsolateSynthesize Cluster-Assembled

Materials in a Liquid Environment

31 Abstract

Experimental results of reactions run with the solvothermal synthesis method in

the search for new Zr-C cluster assembled materials are reported One unexpected

product in single crystal form was isolated and identified by X-ray diffraction to be

[Zr6iO(OH)12O6]middot2[N(Bu)4] with space group P21n and lattice parameters of a =1244 Aring

b=2206 Aring c =1840 Aring α = 90deg β = 105deg γ = 90deg V = 4875 Aring 3 and R1=315 for the

total observed data (I ge2 σI) and ωR2 = 282 This novel hexanuclear Zr(IV)ndashoxo-

hydroxide cluster anion may be the first member in the polyoxometalates class with metal

atoms solely from IVB group and having Oh symmetry or the first member in the

[(Zr6ZX12)L6]m- ion class with halides replaced by oxo- and hydroxyl groups and with an

increased oxidation state of Zr It is predicted to have potential application directed by

both families This work suggests a direction in which the preparation of Zr-C cluster-

assembled materials in a liquid environmentmay eventually be fulfilled

39 32 Introduction

It became evident to me that the deposition of Met-Carsrsquo from the gas-phase has

and inherent bottleneck due to the limited quantity of Met-Cars in cluster beams

generated by the DLV methods and in the low control over the crystallinity of the

deposits Given the same source configuration and deposition surface without suitable

modification the situation is not expected to be easily amended Alternative synthesis

strategies need to be designed and evaluated

Synthesis and isolation efforts for compound (different from C60 ) nanoclusters

including Met-Cars have received limited attention in the literature1-4 This could be due

to limited advances in technique developments in this field In order to bring more

success to isolating unique compound clusters it should be beneficial to understand the

similarities as well as the differences between C60 and Met-Cars Therefore a brief

comparison is given below

In 1990 Kraumltschmer and Huffman5 reported the macroscopic production and

characterization of C60 it thus became the first example of a cluster molecule found in

gas phase experiments to be isolated This discovery spawned a new field of cluster-

based materials science including metallo-fullerenes carbon nanotubes and metal-filled

nanotubes6 These species are relatively inert and can often be extracted from soot and

dissolved directly as they are produced in ordinary solvents6-8 Unfortunately these

favorable properties are not often found in metal-containing compound clusters1 Met-

Cars case is of no exception2 With the exposed transition metals on the surface Met-

40 Cars have proven to be highly reactive in preparation experiments9-11 theoretical

calculations12-17 and based on spectroscopic evidence18 19 Exposure to air or solvents is

likely to lead to decomposition3 although there is some evidence to the contrary20

Suggestions have been made on the unlikelihood of making bare Met-Cars without

surface passivation18 Another problem is the solubility So far attempts to find a solvent

capable of efficiently dissolving Met-Cars have not met with success2 The best chance

of altering the solubility behaviors of Met-Cars is expected to be found in either surface

ligation21 or in a very unique solvent environment such as supercritical liquid media22

Herein I report a new experimental strategy designed by combining the ideas of in-situ

ligand passivation and supercritical solvation to isolate Met-Cars (or any related

structures) in macroscopic quantity and with sufficient crystalline quality for the desired

structural determination

The hydrothermal method was originally employed to generate zeolite

materials23 However its application has been recently broadened to include cluster-like

material synthesis24-26 In typical hydrothermal synthesis reactions are carried out in

sealed autoclave vessels with Teflonreg liners in the temperature range of 100degC to a few

hundred degrees Celsius under autogenous pressure (generally 10ndash30 atm) Such

conditions exploit the self-assembly of the product from soluble precursors27 When an

organic solvent is used instead of water the method is known as solvothermal synthesis

to distinguish it from the more prototypical hydrothermal method28 In both cases in

general the temperature employed is below the critical temperature of the solvent being

used and this is found to be sufficient29 The advantages of using a hydro(solvo)thermal

41 process for seeking new opportunities to bulk-produce of Met-Cars specifically are

considered in the following terms a) many products prepared by this method have a

cage-like structure which serves as a strong reminiscent feature (in my opinion) shared

by both Met-Cars and zeolites b) new metastable phases rather than the thermodynamic

phase are more likely to be isolated under such non-equilibrium conditions27 28

probably similar to those favoring the formation of Met-Cars through kinetic control30 c)

single-crystal formation is often found in such conditions which has been correlated with

the reduced viscosity of solvents in the vessel so that the diffusion processes are

enhanced to favor crystal growth27 This point is important to realize the structural

solvation of Met-Cars d) altered solubility behaviors22 for both products and solvents are

found which has revolutionary impact in working with conventionally immiscible

solutendashsolvent pairs Moreover ligand capping onto the cluster surface can take place in-

situ due to the close-to-critical conditions27 This represents a very promising technique

in providing alternative pathways to prepare crystalline complexes that are difficult to

obtain by routine synthetic methods31-33 And last such methods are very versatile so that

small changes in one or more of the reaction variables such as reaction duration reaction

temperature pH value of solutions reactants stoichiometry can have a profound

influence on the reaction outcome34 Reports on transition metal-carbido and metal-

carbide species prepared by such methods have been reported in the literature35 36

Therefore it was taken as a promising direction to start and a suitable target to establish

some foundational results

42 Specific experimental designs have to rely on the specific chemical properties of

the target species Therefore chemical reactivates of Met-Cars studied in the gas phase

were carefully reviewed They suggest that Met-Cars have very distinctive

differentiation in ligation tendency with respect to different ligands as exemplified in

Figure 3-1 and summarized in Table 3-1

In summary

Figure 3-1 Ti-Met-Car reaction with pyridine9 and methyl alcohol10

Number of

Adducts (L) Adduct Molecule (common features)

Interaction Types

(Met-Cars-L)

810 Butanol methanol water ND3 (moderate size and polar)

Ion-dipole association

49 Acetonitrile pyridine acetone benzene (π-bonding system)

Molecular associationsurface

complexation

111

CH4 Cl2 CHCl3 C6H5Cl CH2F2 (small nonpolar or

halogen-containing) Atom abstractionoxidation

Table 3-1 Summary of Met-Cars reactivityrsquos studied experimentally in the gas phase

43 Options of the capping ligands and the solvent are then evaluated Pyridine

(boiling point 1152 degC37) was chosen as the capping ligand with special attention paid to

avoid introducing any oxygen-containing species This consideration is based on the fact

that oxidation often causes metal-carbon clusters to decompose into simple metal

carbides3 In addition its low boiling point fits the temperature requirement (below 250

degC ) suggested by the manufacturerrsquos (Parrreg Scientific Instrument) for Teflon liners

Toluene （boiling point of 1106 degC and critical point of 319 degC and 41 bar38）and

ethylenediamine (ldquoEDArdquo for short boiling point of 116 degC critical point of 305 degC and

1634 bar39) were chosen as the reaction solvent out of similar reasoning as well as its

availability in practice

However ldquonot everything can take place according to the planrdquo40 searching new

Zr-C clusters a new hexanuclear Zr(IV)ndashoxo-hydroxide cluster being electrostatically

stabilized by tetrabutylammonium cations and with formula [Zr6iO(OH)12O6]middot2[N(Bu)4]

was isolated and tentatively identified by single crystal diffraction Its space groups is

P21n and lattice parameters are a =1244 Aring b=2206 Aring c =1840 Aring α = 90deg β = 105deg

γ = 90deg V = 4875 Aring3 and R1=315 for the total collected reflection (I ge2 σI) and ωR2 =

282 Being reported for the first tine it may represent a new member (or bridge) of

two families simultaneously see Figure 32 and the following discussion (vide infra)

For instance the oxidation state and the coordination environment of metal resemble

those in polyoxometalates (discovered by Keggin41 ldquoPOMrdquo for short) but with group

IVB metal for the first time42 On the other hand its global symmetry relative atomic

44 positions (including the interstitial atom which is not necessary in POM) electron

counting43 and possible 3D linkage are almost identical with the [(Zr6ZX12)L6]m- ions44-57

having generalized formula [(Zr6ZX12)L6]m- (X = Cl Br I as the bridging ligands Z = H

Be B C N Al Si P Fe Co Ni Cr Mn as the interstitial element) The only obvious

difference with this model is the ligands which are not composed of halogens but rather

being replaced by oxo- and hydroxyl groups To the authorrsquos best knowledge such

deviation from the classical Corbett model is reported for the first time It is the two-fold

resemblance to two families of clusters that suggests that it may have diverse potential

applications including molecular spin qubits58 enantio-selective oxidation59-61 negative

thermal expansion62 63 piezoelectric64-66 and superconductive materials67 68

Figure 3-2 Structures of (left) Kegginrsquos ion69 and (the right) and [(Zr6ZX12)L6]m-52(M=metal Z=interstitial atom X=halogen atoms with two position Xi and Xa)

As one will see soon the focus of the current report will be on the structural

analysis from X-ray diffraction results on this new cluster so the majority of correlation

will be made based on the [(Zr6ZX12)L6]m- ion unless otherwise specified A brief review

45 is given here with related aspects Interested readers may be referred to a few excellent

reviews devoted just to this structure49 52 70-72 First Corbett and his colleagues

pioneered the synthesis and crystallographic characterization of the ldquocentered

hexanuclear zirconium halide clustersrdquo starting from mid-1980rsquos44-48 54-57 73-75

Continued family growth came from contributions made by more extended research

groups in addition to Corbettrsquos76-78joined by Hughbankrsquos53 79-89 and Cottonrsquos90-95 with

different research focuses While Hughbanks and his colleagues reported a series elegant

excision methods which enabled cyclic voltammetric analysis for the redox properties

Cottonrsquos group focused on the hydride (H- centered) Zr6-halide clusters studies for both

fundamental and energy application reasons They have well-established a counting rule

of the ldquocluster-bonding electronsrdquo (CBE)54 to be 14e for Z = main group elements

(extendable to be 12e or 16e in some cases) and 18e for Z= transition metal elements

based the Extended Huumlckel Molecular Orbitals (EHMO) calculations57 79 Such theorems

repeatedly explain the stabilities of this family of clusters

This field is featured by heavy-reliability on the single crystal diffraction results

to identify new phases thus providing a solid basis for the discussion herein Except for

the voltammetric studies focused by Hughbanks other auxiliary techniques72 have been

limited to Z(interstitial)-NMR (such as 11B-NMR86 1H-NMR91 92 95 and 13C-NMR80 96

55 as well as Mn-NMR80 ) and Z(interstitial)-Moumlssbauer97 only

46 33 Experimental

331 Material Synthesis

All manipulations were carried out under ambient conditions

Zirconium chloride (ZrCl4) zirconium carbide (ZrC4 100 mesh) were purchased

from Sigma-Aldrich and kept in a sealed desiccators prior to and after the experimental

manipulation Laser-ablated Zr-graphite (in 23 molar ratio) soot was collected by

peeling off from the inner wall of the pellet holder (in Chapter 2) Estimated weight is

~300mg No more purification was performed on any solid materials All organic

solventsreactants EDA( (-CH2NH2)2 Alfa-Aesar 99) pyridine (C5H5N Aldrich

HPLC) toluene (C6H5-CH3 Burdick amp Jackson ACSHPLC) 1 2 4-

Trichlorobenzene (C6H3Cl3 ldquoTCBrdquo for short Aldrich ReagentPlusreg ge99) acetonitrile

(CH3CN guaranteed reagent ACS Grade 995 minby GC VWRreg) n-hexane (Alfa-

Aesar environmental Grade 95+ ) and concentrated HCl acid (37 density 118

gml Ashland Chemical) were used as received Liquid transfer was conducted with

disposable Pasteur pipettes (flint glass 146 cm long estimated volumedrop is 004

mldrop 14672-200 VWRreg)

The general synthesis reaction was carried out under conventional hydrothermal

conditions In a typical process (Figure 32) 2 mmole of metal-containing starting

material (except for the soot which is very limited in quantity and all was used) was

added with 10 ml EDA or 1~25 ml pyridine plus 9~75 ml toluene were placed in a

Teflon-lined stainless steel autoclave (Parr instrument company volume 45 ml) After

47 sealing the autoclave was kept at 200degC for 16 to 20 hours and then cooled to room

temperature The products were collected by centrifugation at 2000 rpm for ~10 minutes

and washed with the employed solvent (either EDA or a mixture of pyridine and toluene)

and several times subjected to centrifugation solids were then dried in air at room

temperature for immediate powder X-ray diffraction (P-XRD) analysis Liquids were

collected as supernatant from each sample in disposable borosilicate glass scintillation

vials (20 ml 66022-081 VWRreg) for immediate nuclear magnetic resonance (NMR)

analysis and then capped (polypropylene cap VWRreg) in the vials

Figure 3-3 Basic illustration of experimental setup

48 332 Single Crystal Growth

Only in case I where the ZrCl4 was used needle-like yellow crystals formed

within a few days after the reaction and with high yield (~85 based on EDA amount)

Other reaction products did not exhibit good crystalline purity to be able to be identified

However over ~15 years sitting on shelf oily particles with color from amber or dark

brown were observed (Figure 34) from the ZrC soot and ZrC sample solutions A few

cycles of re-dissolving (solution volume ranged from ~4 to 12ml depending on the

observed amount of solid particles) assisted with sonication (3 to 5 hr) and slow-

evaporation (1 to 3 days) in vacuum-connected desiccators (backed with in-house

vacuum-line Chemistry Research Building University Park PA) were employed to seek

the appropriate solvent for crystal growth in large quantity and improved quality

Figure 3-4 Crystals in mother liquor (30times)

The dissolving solvent including the crystalline products as solute was layered

with another solvent which is immiscible lower in density lower in boiling point and

lower in the soluent-solubility (by estimation and trial-and-test) The evaluated

49 dissolvinglayering solvent pairs ranged from pyridinetoluene tolueneacetonitrile

124-trichlorobenzeneMilliporereg water 124-trichlorobenzeneacetonitrile with the last

combination worked most effectively Polar solvents such as pyridine did not dissolve

the particles well The strong non-polar solvent n-hexane often caused precipitate 124-

trichlorobenzene dissolved the solid most properly

The high viscosity made the dissolving slow and difficult in general During the

later dissolving trials 2 small drops of 37 concentrated HCl was carefully added to the

layering solvent without disturbing the interfacial layers and phase separation was

observed immediately yellow oily liquids for the bottom phase amber or dark brown

from the top phase Different crystals were grown from the liquors from both phases as

by-products listed in Table 32 and Table 33 as the Zr6-oxo-hydroxide cluster (from the

bottom yellow oily phase) in Table 34 in the Results Section

333 Structures Determination

Crystals with sufficient size and of good quality for diffraction analysis were

grown for ~3-4 weeks duration after the above described treatment They were inspected

and separated from the solvent manually using a Leica MZ75 10-80X stereomicroscope

Paratone oil was used to secure the crystals onto the fiber loop of the holder The X-ray

diffraction data of [Zr6O(OH)12O6]2- cluster anion (vide infra) in particular was collected

from one crystal (approximate dimensions 022 mm times 035 mm times 025 mm) on a Bruker

SMART 98 APEX diffractometer equipped with a graphite-monochromatic Mo Kα

radiation (λ=071073Aring) employing a CCD area detector at 110 K The collection frames

50 were integrated with the Bruker SAINT Software package using a narrow-frame

integration algorithm The structure was solved by direct methods in P-1 and refined on

F-2 (full matrix absorption corrections with SADABS) using the SHELXTL V614

package99

334 Mass Spectrometry Analysis

In order to confirm the stoichiometric information inferred from the diffraction

characterization mass spectrometry analysis was performed on the single crystal of Zr6-

clusters in solution phase The crystal sample was picked up manually under microscope

(~three grains estimated weight ~01mg) and dissolved in acetonitrile for mass

spectrometry measurement

Electrospray Ionization Mass Spectra (ESI-MS) in negative-ion mode and in

normal mass confirmation mode (plusmn 01 for integer value for mz around and larger than

1000) were recorded on a Micromass Quattro-LC single quadropole mass spectrometer

(100 degC source temperature 125 degC desolvation temperature 20-28 kV capillary

voltage 50V cone voltage) The samples were introduced by direct infusion with a

Harvard syringe pump at 10 microlmin using mobile phase solution of 95 acetonitrile and

5 10mM CH3COO-NH4 (referred to as ldquoNH4OAcrdquo later)

Matrix-Assisted Laser Desorption Ionization mass spectra (MALDI-MS) in a

negative-ion reflectron and singlet-ion mode were recorded on an ABI 4800 MALDI

TOFTOF proteomic analyzer (at Hershey Medical School of the Pennsylvanian State

51 University Hershey PA) The matrix was re-crystallized α-cyano-4-hydroxycinnamic

acid (CHCA) 5mg in 1ml H2OAcetonitrile (vv=11) with 01 trifluoroacetic acid

(HTFA) to eliminate any adverse effects potentially caused by salt ion (Na+ and NH4+)

adducts 200microl of the above mentioned single crystal solution was loaded with the matrix

on a sample plate which was exposed to 500 laser (NdYAG at 353nm) shots per spot

The spot size is about 15 mm in diameter by estimation Calibration was performed

using the PerSeptive Biosystems (Framingham MA) ldquoCal mix 5rdquo to calibrate the mass of

singlet in the range of 790 to 2000amu

The mass assignment is made based on the integers closest to the center mass

maxima of each isotope multiplet by comparing with the characteristic isotope

distribution pattern simulated with open-source software ldquoisotope distribution calculator

and mass spec plotterrdquo by Scientific Instrument Service Inc100

335 Other Techniques for All Immediate Analysis

Powder X-ray diffraction (P-XRD) patterns were obtained on a Phillips X-Pert

MPD diffract meter (operated at 35 kV voltage and 30 mA) using monochromatized

CuKα ( λ =15418 Aring) radiation Scans were done in θ-θ geometry with samples held on

a quartz zero- background plate under ambient conditions The samples were deposited

on slides and dried at room temperature

NMR spectra were recorded in CDCl3 on the high-resolution liquid-state NMR

spectrometers (Brukers AV-360 for H-NMR and Brukers DPX-300 for 13C-NMR) at the

NMR Facility Chemistry Department University Park operating at 9056 MHz for H-

52 NMR and 7548 MHz for C-NMR with a 30_ tip angle (3 micros) and a 2 s recycle delay on

a 5mm QNP probe and multinuclear BBO probe respectively Chemical shifts were

reported in ppm downfield from tetramethylsilane (TMS) with the solvent resonance as

the internal standard for 1H and 13C

34 Results

341 Start with ZrCl4 (Case I)

In reactions with pyridine in EDA ZrCl4 produced a light-yellowish translucent

prism single-crystal species in high yield (~85 by estimation) This crystalline product

was identified by single-crystal-XRD to be trans-1458-tetraazodecalin101 (C6H14N4)

(see Figure 3-5) This conclusion is further confirmed by the 1H-NMR and P-XRD (less

significant omitted here) characterizations which show excellent agreement with those

reported101

53

Figure 3-5 Single-crystal reflection resolved C6H14N4 structure (blue-shaded ball N gray-shaded C hydrogen was omitted for clarity adopted from101)

Even being situationally non-significant such bidentate ligands produced in-situ

could be used as spacer units to link metal clusters into 3D networks60 It could be part of

a future exploration which might lead to novel hierarchical structures and applications

342 Start with Zr-graphite Soot (Case II)

Immediate 13C-NMR analysis on the liquid product showed three interesting

resonances at ~ 130ppm ((s)1286 ppm (d)1332 ppm-1306 ppm) possibly indicating a

motif where the metal atom is coupled with carbon-carbon double bonds59 P-XRD data

on the solid product could not provide indexable patterns for phase identification

Over lengthy setting times or upon the acidification of the mother liquor some

single crystals were acquired Results from these single crystals (partially refined and

54 therefore named after the documentation record) are listed in Table 32 being referred to

as ldquoby-productrdquo with respect to the ldquomain productrdquo [Zr6O(OH)12O6]2- (vide infra)

File Name (Log pg)

Lattice Constant Formula a

Starting

material Note

aug48 (pg B40) [N(CH3)4] middot [C6H5-COO]a ZrC soot yellow

supernatant

jlg2 (pg B42)

jlg5 (pg 27) [ZrCl4] and [ZrCl4]2

a ZrC soot clear

(a bc)(αβ γ)(V) for

jlg5

542Aring 505 Aring 2172 Aring 90deg 91deg

90deg V=1203Aring3

a Structures are approximately refined by SHETXL V64 omitting hydrogen atoms with R of ~5 to

8 Table 3-2 By-product crystals from Case II indicating some organic reaction pathways

343 Start with ZrC (Case III)

3431 By-products

Immediate analysis on fresh products showed similar results as those in case II

Similarly also long setting times (15 year) enabled some single crystals to be able to be

isolated and characterized by XRD listed in Table 33 Although not significant by

themselves (thus being referred to as ldquoby-productsrdquo as well) they (together with products

listed in Table 32) are very valuable in terms of being ldquosign polesrdquo of minor reaction

55 routes in addition to the possible ldquomainrdquo formation pathways We will revisit these two

tables in Discussion 356 and 357

File Name (Log pg)

Lattice Constant

Formula a b Starting material

Note

jlg6 (pg 31) [ZrCl3] middot [C6H5-COO]a ZrC clear

(a b c)(αβ γ)(V)

1994 Aring 137 Aring 44 Aring 9015deg 958deg 9001deg

591 Aring3

jlg8 (pg 32) jlg9 (pg 87)

[tBu-NH3]middotClb ZrC

brown top

phase c

(a b c)(αβ

γ)(V) 86 Aring 89Aring 178Aring

90deg 90deg 90deg

1373 Aring3

jlg10 (pg 91) [(CH3)3N-(CH2)6-N(CH3)3] middot 2Cl middot H2Ob ZrC amber

top phase c

(a b c)(αβ γ)(V)

761Aring 826Aring 838Aring 99deg 912deg

916deg 520 Aring3


8 b Structures are identified based on the matching of the lattice parameters (collected by SMART software package) with in-line Cambridge Crystallographic Data Centre (CCDC) database searching c Crystals grew from the top polar solvent phase when phase separation was observed

Table 3-3 Lattice parameters of selected by-products crystals

56 3432 Significant Crystallographic Results

Characterizations of one single crystal product produced after a lengthy (~15

years) setting period revealed a fascinating structure (see Figure 36 below) with a cluster

anion with a high symmetry configuration ie Oh It was composed of a Zr6 core capped

by twelve hydroxyl (micro-OH) groups and six oxo-ligands (oxo-O) and centered by one

interstitial oxygen (i-O) (Note that ldquomicro-ldquo ldquooxo-ldquo and ldquo i-ldquo in left superscript forms are

used throughout this chapter to indicate the bridging terminal oxo and interstitial

characters of these ligands respectively) It bears two units of negative charge balanced

by two cations [N(nBu)4]+ to form a neutral cluster molecules [Zr6O(OH)12O6]middot

2[N(nBu)4]

Figure 3-6Ball-stick presentation of the crystal structure of [Zr6O(OH)12O6]middot 2[N(n-Bu)4] Atoms are number- as well as color- labeled The centre oxygen is O100 and bridging oxygen atoms are O10 ( =1 to 12) Colored labels red for oxygen green for zirconium and blue for nitrogen gray for carbon

57 The crystallographic and structure refinement details are listed in Table 3-4

below One can tell the excellent quality of the refinement reflected by the impressively

low R values residual charge density and the goodness-of-fit

Formula C32H84N2O19Zr6

Formula weight 134833 Wavelength of the Mo(Kα) (Aring) 071073 Generator power 1600 W (50 kV 32 mA) Detector distance (cm) 58 Data collection method φ-2θ scans θ range for collection (degree) 147-2830 Temperature (K) 110 (1) Crystal size (mm3) 022 times 035 times 025 Crystal habit Brown cube Crystal system Monoclinic Space group P21n Unit cell dimensions a (Aring) 124375(18) b (Aring) 22061(3) c (Aring) 18402(3) Α (deg) 9000 Β (deg) 105102(3) γ (deg) 9000 Volume (Aring3) 487494(12) Z 4 Density (calculated) ( gcm3) 1837 Reflection collected 23033 No of observations (Igt2σI) 10638 F(000) (e)- 2728 Restrainsparameters 0533 Absorption coefficient (m-1) 1304 Goodness-of-fit on F2 1118 Final R indices [Igt2σ(I)] 282 Final R indices (all data) 315 Largest diff peakhole (e Aring3) 0694-0995

[ ] ( )

( )

1 22 2

2 2 24

o c o o c o

o o

R F F F R F F F

with F F

ω ω

ω σ

= minus = minus

=

⎡ ⎤⎣ ⎦⎡ ⎤⎣ ⎦

sum sum sum sum

Table 3-4 Crystallographic Data for [Zr6O(OH)12]O6middot2N(nBu)4

58 Each unit cell is composed of four such cluster molecules making it belong to

ldquomolecular crystalsrdquo43 Alternatively it can be viewed as being composed of giant

cations and giant anions ionically bound in one unit cell in a 12 ratios From this point

of view this species can be classified as an ldquoionic compoundsrdquo More views along the

symmetry axes of the anions are presented in Figure 37 along with the packing motif

which contains a very intense hydrogen-boding network presented by the relative

orientation between the red (oxygen) and the gray (carbon with hydrogen atoms) balls

Figure 3-7 Ball-stick presentation of the crystal structure of [Zr6O(OH)12O6]middot 2[N(n-Bu)4] (From the top left to the right) views from four-fold and three-fold axes and (the bottom middle) the packing for one unit cell (colored lines represent a (red) b(green) c (blue) axes respectively) Colored labels red for oxygen green for zirconium and blue for nitrogen gray for carbon Notice the relative orientation and distance between the red and the gray balls which indicatesthat strong hydrogen bonding Hydrogen atoms are omitted for clarity

Views from symmetry axes and packing motif containing hydrogen networks

59 More crystallographic details are listed in Table 3-5 to Table 3-7 based on the

numbering labels in Figure 36

Atomic positions of [Zr6O(OH)12]O6middot2N(nBu)4 Atom X-frac Y-frac Z-frac Isotropic

Zr1 065564(2) 0167183(12) 0198271(13) 001585(7)Zr2 054224(2) 0152355(12) 0339232(14) 001603(7)Zr3 049081(2) 0051652(11) 0203977(13) 001431(7)Zr4 080963(2) 0130135(11) 0366079(13) 001411(7)Zr5 075826(2) 0029954(11) 0230007(14) 001598(7)Zr6 064506(2) 0015171(12) 0371397(14) 001835(7)O1 092614(18) 015888(10) 042485(12) 00253(4)O2 083724(19) -001528(10) 019068(13) 00283(5)O3 06595(2) 022160(10) 013489(12) 00289(5)O4 046536(19) 019856(11) 037834(12) 00292(5)O5 037260(18) 002580(10) 014442(12) 00265(5)O6 06405(2) -004009(11) 043412(12) 00332(5)

O101 086610(17) 007127(10) 030708(11) 00231(4)H101 09419 00635 03159 0028O102 051397(18) -000111(10) 028902(11) 00249(4)H102 04654 -00328 0291 003O103 078627(18) 018260(9) 028039(11) 00231(4)H103 08353 0214 02783 0028O104 060715(17) 000940(9) 017457(11) 00215(4)H104 05923 -00192 01361 0026O105 052629(17) 012131(10) 014978(11) 00227(4)H105 04823 01319 01024 0027O106 055796(18) 007988(10) 039878(11) 00262(5)H106 05254 0076 04387 0031O107 069358(17) 017248(9) 039507(11) 00226(4)H107 07084 0201 04336 0027O108 057102(18) 020324(10) 026015(11) 00241(4)H108 05451 02429 02528 0029O109 077488(18) 006074(10) 042088(11) 00244(4)H109 08186 00502 04683 0029O110 043422(17) 011088(10) 026323(11) 00247(4)H110 03584 01185 02548 003O111 074214(17) 010189(9) 017105(11) 00228(4)H111 07743 01056 0131 0027O112 072957(19) -002024(9) 030934(11) 00243(4)H112 07558 -00598 03168 0029O100 065036(15) 009095(8) 028505(9) 00168(4)

N2 11803(2) 002933(11) 034511(13) 00216(5) Table 3-5 Atomic positions of [Zr6O(OH)12]O6middot2N(nBu)4

60 Spacing purpose

(Cont) Atomic positions of [Zr6O(OH)12]O6middot2N(nBu)4 Atom X-frac Y-frac Z-frac Isotropic

N1 08191(2) 033959(11) 044026(13) 00230(5)C1 10035(3) 01508(2) 01541(2) 00488(10)

H1A 09484 01603 01083 0073H1B 10538 01843 01681 0073H1C 09675 01431 01934 0073C2 09832(4) 03070(2) 02577(2) 00515(11)

H2A 09997 02888 02144 0077H2B 09955 0278 02979 0077H2C 10308 03415 02734 0077C3 04553(4) 04020(2) 03572(3) 00608(13)

H3A 03864 04166 03649 0091H3B 04434 03885 03062 0091H3C 05094 0434 0367 0091C4 01955(3) 024054(17) 04586(2) 00413(8)

H4A 02426 02658 04962 0062H4B 01277 02322 04725 0062H4C 01785 0261 04109 0062C5 10883(3) 012717(16) 059798(19) 00323(7)

H5A 11335 0135 05639 0048H5B 11351 01242 06484 0048H5C 10361 01597 05952 0048C6 04433(3) -014838(15) 043809(17) 00299(7)

H6A 04753 -01823 04186 0045H6B 03916 -01627 04649 0045H6C 05013 -01256 04716 0045C7 02943(3) 024899(16) 019299(18) 00328(7)

H7A 03206 02828 02256 0049H7B 03198 0212 02192 0049H7C 02143 02493 01779 0049C8 02850(3) -007793(18) 000945(19) 00366(8)

H8A 02428 -00414 -00046 0055H8B 02828 -00896 00593 0055H8C 02535 -01096 -00253 0055C9 04032(3) 010941(13) -003200(16) 00239(6)

H9A 03998 00979 00182 0029H9B 03804 00745 -00644 0029C10 03390(3) 025358(14) 012340(17) 00259(6)

H10A 04197 02542 01389 0031 Table 3-5 (continued) Atomic positions of [Zr6O(OH)12]O6middot2N(nBu)4

61


H10B 0314 02914 00975 0031C11 11095(2) 000596(14) 039549(16) 00231(6)

H11A 11574 00004 04458 0028H11B 10553 00369 03984 0028C12 08384(3) 028833(13) 049776(16) 00241(6)

H12A 09175 02794 05126 0029H12B 08007 02525 04731 0029C13 08622(3) 032742(15) 023751(17) 00303(7)

H13A 08147 02926 02203 0036H13B 08501 03561 01962 0036C14 10257(3) 006821(15) 057650(16) 00255(6)

H14A 10787 00356 05782 0031H14B 09795 00712 05253 0031C15 03285(3) -005269(14) 039924(16) 00249(6)

H15A 03857 -00255 04273 003H15B 02829 -00655 0432 003C16 07492(2) -008206(14) 061545(16) 00236(6)

H16A 07076 -00688 05659 0028H16B 06958 -00925 06435 0028C17 03820(3) -010764(14) 037276(16) 00261(6)

H17A 04343 -00939 03453 0031H17B 03247 -01312 03385 0031C18 10477(3) -005319(14) 037066(16) 00249(6)

H18A 11007 -00857 03719 003H18B 10018 -00493 03194 003C19 04049(3) -006711(14) 000779(17) 00271(6)

H19A 04359 -00346 00423 0033H19B 04065 -00545 -00424 0033C20 02555(3) 018113(15) 045266(18) 00300(7)

H20A 03249 01899 044 0036H20B 02733 01608 05011 0036C21 02566(3) -002023(14) 033016(16) 00241(6)

H21A 03055 -00026 03026 0029H21B 02111 -00503 02977 0029

Table 3-5 (continued) Atomic positions of [Zr6O(OH)12]O6middot2N(nBu)4

Spacing purpose

62

Atom X-frac Y-frac Z-frac IsotropicC22 05231(3) 012410(14) -002960(16) 00261(6)

H22A 05503 0156 00069 0031H22B 05277 01384 -00785 0031C23 08001(3) 029944(14) 056911(16) 00243(6)

H23A 07195 03026 05566 0029H23B 08314 03371 05926 0029C24 11024(2) 004903(15) 027077(16) 00248(6)

H24A 10572 00145 02489 003H24B 10525 00797 02811 003C25 07036(3) 036725(14) 042883(17) 00264(6)

H25A 06953 03997 03923 0032H25B 06985 0385 0476 0032C26 06671(3) -018783(13) 013254(15) 00244(6)

H26A 07249 -0218 01498 0029H26B 0596 -02086 01219 0029C27 10680(3) 009479(19) 014209(19) 00405(9)

H27A 11036 0103 01021 0049H27B 10158 00618 01255 0049C28 08147(3) -013913(15) 060667(18) 00295(7)

H28A 08816 -01277 05922 0035H28B 0837 -01602 06545 0035C29 11574(3) 007416(17) 021252(18) 00324(7)

H29A 12038 00432 01987 0039H29B 12045 01082 02336 0039C30 04971(3) 034978(17) 04101(2) 00378(8)

H30A 0441 03181 04007 0045H30B 05071 03636 04614 0045C31 06073(3) 032287(16) 040217(19) 00327(7)

H31A 06232 02859 04315 0039H31B 06001 03126 03499 0039C32 06722(3) -014281(14) 019599(16) 00283(7)

H32A 06229 -0109 01771 0034H32B 07473 -01271 02135 0034


63 Selected bond lengths of [Zr6O(OH)12]O6middot2N(nBu)4

Atom1 Atom2 Length (Aring)Zr1 O3 1683(2)Zr1 O105 1913(2)Zr1 O108 1913(2)Zr1 O103 1939(2)Zr1 O111 1940(2)Zr1 O100 23318(18)Zr1 Zr2 32759(5)Zr1 Zr5 32783(5)Zr1 Zr4 32849(5)Zr1 Zr3 32897(5)Zr2 O4 1682(2)Zr2 O110 1902(2)Zr2 O106 1919(2)Zr2 O108 1944(2)Zr2 O107 1946(2)Zr2 O100 23102(18)Zr2 Zr4 32694(6)Zr2 Zr3 32727(5)Zr2 Zr6 32788(6)Zr3 O5 1688(2)Zr3 O102 1911(2)Zr3 O104 1914(2)Zr3 O105 1944(2)Zr3 O110 1947(2)Zr3 O100 23179(18)Zr3 Zr5 32701(6)Zr3 Zr6 32772(5)Zr4 O1 1690(2)Zr4 O107 1908(2)Zr4 O103 1916(2)Zr4 O101 1938(2)Zr4 O109 1943(2)Zr4 O100 23142(18)Zr4 Zr5 32756(5)Zr4 Zr6 32767(5)Zr5 O2 1690(2)Zr5 O111 1903(2)Zr5 O101 1910(2)Zr5 O112 1938(2)Zr5 O104 1944(2)Zr5 O100 23121(18)Zr5 Zr6 32814(5)Zr6 O6 1690(2)Zr6 O112 1909(2)Zr6 O109 1919(2)Zr6 O106 1936(2)Zr6 O102 1949(2)Zr6 O100 23193(18)

Table 3-6 Selected bond lengths of [Zr6O(OH)12]O6middot2N(nBu)4

64

a) Selected bong angle measurements

b) Corresponding bond angles measured Atom1 Atom2 Atom3 Degree

O4 ZR2 O107 10238O107 ZR4 O1 10278

O1 ZR4 O101 1035O101 ZR5 O2 10303

O2 ZR5 O104 10309O104 ZR3 O5 10424

O5 ZR3 O110 10202O110 ZR2 O4 10351ZR2 O107 ZR4 11601ZR4 O101 ZR5 11667ZR5 O104 ZR3 1159ZR3 O110 ZR2 11645ZR2 O100 ZR4 8995ZR4 O100 ZR5 9014ZR5 O100 ZR3 899ZR3 O100 ZR2 9002

c) Schematic bisect configuration

Figure 3-8 The measurements of selected bond angles (top) the result table (middle) and the schematic representation of the bisect view (bottom) with the averaged angles labled 116deg (Zr-microO-Zr) 90deg (Zr-iO-Zr) 103deg (oxoO-Zr-microO)

65 The average Zr-Zr bond length is 3277(6)Aring Zr-oxoO (axial position) bond length

is 1687(3)Aring Zr-microO (bridging position) bond length is 1929(16)Aring and Zr-iO (interstitial

position) bond length is 2318(8)Aring All these standard deviations are smaller than the

structural refinement factor R (28) Therefore if there is some distortion of the

symmetry from octahedron (Oh) to trigonal antiprism (C3v) it is negligible The bisect

configuration is almost identical along x y and z axes composed of Zr4(OH)4(O)4 in the

square-based shape (Figure 38) with 801 Aring as the axial(O)-axial(O) diagonal distance

further supporting its Oh symmetry Selected bond angle measurements are listed in

Figure 5 a) and b)

3433 Mass Spectrometric Results

Under the mode of normal mass confirmation all negative-ESI-MS peaks can be

assigned in reasonable consistency with the molecular formula reported in Table 34

Calculated anionic masses based on [Zr6O(OH)12]O62- are in good agreement with the

detected mass within plusmn1 amu range The negative-ES-MS results are mz 440 for

[Zr6O(OH)12O6]middot[H2O]2- (doublet is evidenced from the half-mass separation in-

between the mass signal) mz 8804 for [Zr6O(OH)12O6]middot[NH4]- (singlet is evidenced

by the unit mass separation in-between mass signals) mz 9015 for

[Zr6O(OH)12O6][NH4][H2O]- mz 11218 for [Zr6O(OH)12O6][N(nBu)4]- mz 11578

for [Zr6O(OH)12O6][N(nBu)4][2H2O]- and mz 11938 for

[Zr6O(OH)12O6][N(nBu)4][4H2O]-

66

Figure 3-9 Negative-ESI-MS results convey the stoichiometric information which can rationalize all major peaks to be associated with one anionic species [Zr6O(OH)12O6]2- (inset blown-up region around 8804 amu right (experimental) and left (simulated) )

ESI-MS is a very sensitive technique even a small drift in the

electronicmechanical component could generate responding signals All mass

assignments are made with the plusmn1 amu tolerance (especially for the high mass range102)

with respect to the maximum peak in one multiplet as well as with the very characteristic

isotope pattern of Zr6 When a plusmn1-amu-drift was observed from spectra obtained by

different timing-averages the separations in-between peaks and the overall profile for

67 each peak were carefully re-examined to assure the quality of the data Signals without

the characteristic isotope distribution andor with intensity less than 1 were omitted

Negative-MALDI-MS shows only one envelope of peaks with distinctive isotope

patterns as well as appreciable intensity centering at 864 to 866 amu It is assigned to

the singly protonated anionic cluster of [Zr6O(OH)12O6][H]- (calculated mass centers

from 862 to 864 amu detailed discussion for this discrepancy is given below) Signals

without the characteristic isotope distribution andor with intensity less than 1 are not

discussed herein

Figure 3-10 Negative-MALDI result exhibits a protonated [Zr6O(OH)12O6][H]- peak with 2 amu shift compared with the simulated (inset) pattern See detailed discussion in the text

68 35 Discussion

351 Atomic Arrangement in the Structure

The hexanuclear of zirconium atoms form an ideal octahedron with Zr-Zr-Zr

angles at 60deg and Zr-Zr distances ranges from 3270Aring to 3290Aring with an averaged value

of 3277(6)Aring This bond length is substantially larger than that in bulk Zr metals ( R Zr-Zr

= 266Aring 103) indicative very weak metal bonding Comparable bond lengths can be

found in two of Corbettrsquos ions Zr6I14C (15e) with Zr-Zr distance of 3283(2) Aring57 and of

3292(2) Aring seen from Zr6I12B (15e)56 Other factors such as the matrix effect54 and

valence radii of the interstaila atoms 104 play much less role than the electronic cause

The Zr-(2micro-OH) distance ranges from 1903(1)Aring to 1951(1)Aring with an averaged

value of 1929(16)Aring Compared with (3micro-OH)-Zr distance in [Zr6(OH)2(O)6] with a face-

bridging OH ligand105 106 itrsquos larger by ~036Aring such shortened distance could be related

with the hybridization of oxygen orbital changed from sp3 in (3micro-OH)43 to sp2 in (2micro-OH)

An average Zr-microO-Zr bond angle of 116deg (Figure 38) further supports this hybridization

mechanism Such an sp2-bridging motif does not form in classical [(Zr6ZX12)L6]m- ions

where an 83deg 56 sharp angle is found for Zr-X-Zr angles X=Cl Br I) representing typical

lone-pair electron donating feature56 for halogen ligands In other πO-Metal complexes

almost equal bond lengths (such as 1930(3)Aring 1960Aring 1970(0)Aring and 1910(6)Aring

1945(2)Aring respectively) can be found in many literature documents61 107-110 Most of

them are cyclopentadienyl (Cp) stabilized Zr(IV) complexes with a general formula as

69 (Cp)2Zr(Cl)OR The key feature in common is that the Zr is in the highest oxidation

state thus with empty (or lowndashfilled in the structure herein) d orbitals to accept π

bonding from the oxygen Such strong π bonding interactions of Zr-OH are found to the

inorganic zirconia ldquopolymerrdquo111 prepared from sol-gel methods as well This π bonding

will be further rationalized in the section following with an orbital diagram as the

reference

The Zr-oxoO distance ranges from 1682(1)Aring to 1690(1)Aring with an averaged value

of 1687(3)Aring This distance is impressively shorter than most Zr-O bond lengths in

natural minerals which range from 2035Aring to 2267Aring112 113 It will have to be correlated

with the multiple bonds between M-oxo-oxygen which have been well studied59 in the

condensed phase and occasionally discussed in the gas phase114 For example WequivO has

been found to be with 166 to 170Aring in W(O)(CHCMe3)Cl2(PR3)115 In contrast Mo=O

(Mo is in the same group as W but one row earlier in the periodic table) bond length is

found to be 1721 Aring59 supported by Infrared (IR) absorption that detected the M=O

stretching mode red-shifted with respect to that for the MequivO Zr is earlier than Mo by 2

in atomic number and presumed to have a larger ionic radus104 while 1687(3)Aring (see

Table 3-6) is even smaller than 1721 Aring (Mo=O) thus far the identification of the

bondings between Zr and the axial oxygen is ascertained to be ZrequivO not Zr-O nor Zr=O

ZrequivO has been very rarely observed before59 and thus represents a new feature of the

currently reported cluster crystal

The Zr-iO (interstitial) distance ranges from 2310(1)Aring to 2331(1)Aring with an

averaged value of 2318 (8)Aring This value is slightly larger than that in the bulk ZrO2112

70 113 but in good agreement with a reported distance 232Aring in CsZr6I14C57 This similarity

again suggests that the skeleton of the Zr6 clusters is highly dependent on its electronic

configuration other factors such as different radii from the center atoms or from

bridging ligands play a much less significant role

The stability of this cluster anions will be accounted for by its electron

configuration in the calculated Molecular Orbitals (MOs) in the future publication116

352 Mass Spectra

Limited by the quantity of sample with high phase-purity the stoichiometric

information could not have been evaluated by any other techniques except for the mass

spectrometry which has the minimum requirement for the sample concentration down to

ppm level117 Therefore results obtained from the ESI-MS and MALDI-MS constitute a

very crucial part of the characterization As reported in the Results part they reasonably

confirm the stoichiometric information and charge status inferred from the single-crystal

diffraction

Oxygen has two isotopes100 (one with 02 in abundance) H and F are both

monoisotopic100 their contribution to the overall pattern is minor Drastically different

zirconium has five natural isotopes 90(100) 91(218) 92 (333) 94 (337) and 96

(54)100 118 which will generate an isotope multiplet in MS with wide mass range and

thus very distinguishable Additionally mass signal for multiple Zrn exhibits very

characteristic alternation-patterns being up-and-down in intensity from one peak to the

71 next This feature is clearly observed in Figure310 (except for the peak 870 which

shows abnormal small intensity with an unknown reason) Letrsquos take a look at the (-)

MALDI first

Detection of protonated species is the basis of MALDI technique117 With HTFA

added in the matrix solution any common contamination of alkaline metals (from ldquopurerdquo

water in preparation of solutions) adduct could be largely suppressed117 Therefore

singly-prontonated MADLI signal should reveal the mass information closest to the

ldquonakedrdquo (with no adduct peaks) cluster stoichiometry This expectation is largely

fulfilled from the reasonable mass assignment being consistent with the diffraction

result However first the simulated pattern shows two maximum at mz 862 amu and mz

864 amu (see Figure 3-10) which is 2 amu smaller than the detected signals Second all

other isotope masses with less than 30 intensity (except for 872 with 36 intensity100)

did not show up While the second discrepancy might be related to the sensitivity limit

the mass shift by 2 amu seems to be more significant While the exact cause is unknown

it could be largely correlated with a few complications involved 1 The mass calibration

limit at the low mass range is at 792 amu (unpublished calibration record is available)

because the specific instrument (ABI 4800 see Experimental) is largely employed for

proteomics studies and the low-mass range is under-explored No other userrsquos data could

be referred to for comparison Such reference is even more unavailable119 120 for a

sample containing multiple metal atoms with multiple isotopes 2 It has been pointed

out that121 in the reflectron mode post-source decay could perturb the centroid of the

isotope multiplet ldquowhich complicates analysisrdquo121 3 Itrsquos unclear how chemically

72 possible it is that a [2H]+ could attach to one bridging OH- ligand or that a F- (from the

HCFA induced laser excitation122) could substitute it Somehow these two hypothesized

species have mass degeneracy (the fluorine has atomic number of 19 and the combination

of [OH+ 2H] has effective mass of 19 amu as well) at those shown in Figure311 ie 864

and 866 amu

Despite these errors (-)MALDI provides the most direct information regarding

the stoichionmetry of the cluster being studied The mass assignment is found with

sufficient confidence to support the diffraction result

It has been pointed out that MALDI-MS and ESI-MS are complementary

techniques119 with ESI-MS bringing more details in the metal-ligand interaction Such

complementary effects were observed and with more details in negative-ESI-MS

In Figure 39 the [NH4]+ and H2O are from the driving solvent (see

Experimental part) the [N(nBu)4]+ is from the cations in the unit cell Detection of

adduct ions (in terms of both solvent orand cationic species) is very common in ESI-

MS123 sometimes it only makes possible to detect neutral species In general and in

practice mass peaks with adducts make the stoichiometric recognition difficult but ldquonot

impairedrdquo123 This statement fits the situation in the (-)ESI-MS analysis Confidence on

the mass assignment was found with such knowledge

Moreover the inclusion of certain numbers of H2O molecules was observed as

shoulder peaks separated from the main peaks by ntimes18 (n=1 to 4) amu It seems to be

73 accidental at first glance but itrsquos actually closely related to the unique hydrogen-bonding

network formed in the intra- and inter-molecules regimes in the structure For instance

the mz 11218 of [Zr6O(OH)12O6][N(nBu)4]- have two shoulder peaks each indicating

2H2O addition to the mz 11578 of [Zr6O(OH)12O6][N(nBu)4][2H2O]- and to the mz

11938 of [Zr6O(OH)12O6][N(nBu)4][4H2O]- the first 2H2O addition could be

attributed to making up the supplementary hydrogen bonding on the ldquotwo missed

available sitesrdquo (see last section) the second 2H2O additions could be attributed to

making up some new hydrogen bonding around the two cations since now the crystals

are in the solution phase They are relatively far apart and more flexible in choosing

orientations in a state slightly away from the optimized rigid network thus creating more

H2O-adduct sites The series of small peaks starting from mz 1400 amu exhibiting

2(H2O) addition pattern 4 times could be related to the formation of dimer-anions by

sharing ligandsmetals Due to their low intensity and uncertainty about the dimer

formation without the corresponding crystallographic data no definitive formula was

assigned

Similarly as in MALDI-MS even some general agreement was reached based on

the maximum peakrsquos matching with proposed stoichiometry there are some

discrepancies in ESI-MS as well One can tell by closer inspection of the isotope

multiplets the experimental and the simulated that the experimental patterns have ~4 to

6 peaks more on each side making the total number of peaks in one multiplet to be ~28

to 30 while there are only ~17 peaks in the simulated pattern Moreover the pattern lost

the characteristic alternating-in-intensity patter of Zr6 However bearing in mind that the

74 cluster anions being studied here have a large number of OH ligands on the surface along

with the axial-O which have some special features in polarity (being slightly δ+ in

polarity59) Without being ascertained with the chemical reactivities of this cluster the

additional small peaks on both side of the assignable mutilplet are temporarily assigned

to be related to the protonhydrogen fluxionally124 in the ESI solution phase and mediated

by the variable oxidation states123 of Zr

For a system with multinuclear metal being isotope-rich and with chemically

active ligands assigning all peaks123 is very challenging even given that little is known

about the analytersquos chemical properties in the solution phase Under the situation that

measurements from two different techniques suggest the same cluster composition as

well as charge status both in agreement with diffraction results Itrsquos safe to conclude

now that MALDI-MS and ESI-MS results are consistent and supporting

353 Classification

As many aspects of Zr6O19H122- have been discussed the charge status has not

been included which has to be accounted for based on ldquoionicrdquo bonding arrangement

although it does not exist59 But it is much easier to evaluate the proposed stoichiometry

than to construct the orbital diagram for electron counting and electron-fillings

Regardless of the controversy the formal oxidation states were assigned as [Zr(IV)6O(-

II)] [(OH)(-I)12] [O(-II)4]59 (alternatively its reduced formula in ldquoinorganicrdquo form

[Zr(OH)2O117]-033 exhibits common oxidation states as in zirconia nano-powders

75 prepared with sol-gel method111) to account for the net two negative charge Comparing

it with [(Zr6ZX12)L6]m- ions125 Zr6O19H122- might be a ldquofurther oxidized [(Zr6ZX12)L6]m-

ionsrdquo being isolated for the firs time

On the other hand it was found that there is remarkably resemblance of the

crystallographic data ie the bond lengths and the angles126 127 between Zr6O19H122- and

unit of POMrsquos such as W6O192- 126 It is well known that POM usually128 have metals

from group V and group VI from the periodic table Zr6O19H122- might be the first42 129

130 ldquogroup IV POMrdquo with mixed ligands of oxo-O and microOH (which probably canrsquot be

further deprotonated to become real ldquoZr6O19rdquo POM) This classification could be further

supported by that fact that almost all [(Zr6ZX12)L6]m- ions were synthesized with the

traditional solid state synthesis methods at very elevated temperature (800degC to 1000degC)

for a few tens of hours or even a few weeks while hydrothermal methods have success

in preparing other POM compounds131 (see Experimental section of this report as well)

in much more mild temperature conditions and shorter reaction duration

Another related structural motif is worthy of brief mention as well which is the

Chevrel phase132 originally discovered by Chevrel and composed of solid networks from

low-valent metal sulfides selenides and tellurides in hexa-or higher nuclearity normally

marked as M6X8L672 Reports with hexanuclear zirconium cluster with 3micro-O 3micro-S and 3micro-

OH105 106 133-136 are available There are two informative reviews 72 80 on how metals

from different groups favor one of the classified prototypes ie M6X12L6137-143 (Figure 3-

11 a) M6X8L6144-150

(Figure 3-11 b) and (Zr6ZX12)L6 (Figure 3-11 c) Interested readers

are referred to them Zr6O19H122-

forms an exception to them

76

In summary Zr6O19H122- is a rule-breaking cluster species

354 Possible Formation Pathway

There are many linkage motifs summarized by Corbett in condensed phase

composed of [(Zr6ZX12)L6]m- ion units49-52 One example is shown below

Figure 3-11 Three types of M6-ligand clusters (Taken from reference80)


77 The proposed formation pathway starts from a similar (as the above) hypothesized

3D lattice by sharing the axial OH ligands followed by an oxidative deprotonation by

N(Bu)4+ as shown below It could be just one of the many possibilities Nevertheless it

helps in explaining some experimental observations

Scheme 1 (disfavored)

Scheme 2 (favored)

Note 1 No intermediate states are specifiedassumed 2 microη-OH is used with η represent its intramolecular hapticity as π bonding ligand and micro for its intermolecular bridging function 3 micro-OH is only intramolecular bridging ligands

N(Bu)4(OH) is well know for its role as a deprotonation agent in organic

solvent151 However such an oxidative72 deprotonation process in scheme 1 is

kinetically disfavored by the low solubility151 of N(Bu)4+ in TCB152 153 and the

immiscibility between TCB and water Upon the addition of a second polar and acidified

solvent acetonitrile plus HCl (see Experimental) the equilibrium shifts to the right by the

favoring phase transfer of H2O and N(Bu)4Cl to the polar solvent This leaves [iOZr6(micro-

OH)12(oxo-O)6]middot2N(Bu)4 with a high concentration in the nonpolar phase ie TCB at the

78 bottom An oversaturation condition is gradually reached whereupon crystallization

follows

This formation pathway is proposed based on both experimental observation and

results from by-products (Table 32 and Table 33) First from the observation based on

phase separation (aforementioned in 332) the brown color on the top polar phase is

supposed to be caused by concentrated [N(Bu)4]+151

The yellowish color was seen in the

nonpolar phase at the bottom and with an oily status A similar phenomenon has been

seen by Hughbanks80 in efforts of excising154 [(Zr6ZX12)L6]m- ions for voltammetry

analysis Even more similarly we both observed that sometimes the condensed sticky

solid could ldquomeltrdquo into oil with a so far unknown reason

More supporting evidence is from the by-products identified by single crystal X-

ray diffraction For example similar TBA salts are repeatedly isolated in crystalline form

from the top polar phase such as the amber crystal of [(CH3)3N-(CH2)6-N(CH3)3] middot

2ClmiddotH2O and the brown crystal of [tBu-NH3]middotCl These tertiary amine salts are not

exactly the same as TBA however one could speculate that they are the co-products with

TBA from many complicated organic reactions over the 15 years of storage time period

Of course there could be the possibility that there are some such species just not formed

in the crystalline that could not be identified

355 What is the origin of the organic cation

Reaction mechanisms in hydrothermal and supercritical conditions are largely

subjects still under investigation155 One recent report156 on the formation of phenol from

79 the inorganic salt NaHCO3 catalyzed by Fe powder is one of such examples Similarly in

the reported case over the 15 years of the crystallization following the solvothermal

reactions many complicated post-synthesis organic reactions could take place While the

origin of the formation of the tetra-alkyl ammonium is not clear at present it is proposed

to arise from the ring-opening reaction of pyridine37 157 and subsequent alkylation on the

nitrogen catalyzed by ZrC or potentially ZrxCy clusters158 159

This proposal is based on careful examination of both the ldquomain productrdquo

[Zr6O(OH)12O6]-2[N(nBu)4] and the ldquoby productsrdquo (in Table 32 to 33) In addition to

[N(nBu)4]+ found in the main product there are other four tertiary amine ldquopiecesrdquo

isolated [N(CH3)4]+ [(CH3)3N-(CH2)6-N(CH3)3]2+ [tBu-NH3]+ and [nBu-NH3]+

suggesting that they all possibly from the ring-opening products of pyridine Detailed

organic reaction mechanisms in form of step-by-step can not be provided since no any

intermittent species were extracted In-depth knowledge and experience sharing are

cordially welcomed and appreciated by the author

356 Prospects

Normal zirconium zirconium hydroxides160 ( Zr(OH)4 ) are amorphous white

powders hydroxyl-bridged zirconium polymer160 Zr-propionate is a white powder with

the propionate carboxyl group bound to Zr bearing polymer characters The herein

reported Zr6-oxo-hydroxide cluster formed in high symmetrical crystals must posses its

own uniqueness in its potential application More characterizations of it should greatly

enhance our knowledge about its properties and thus its potential application in many

80 fields The author has mentioned some examples in the Introduction section the

corresponding details are given as follows

Interesting optical magnetic properties could possibly be explored by

manipulating the interstitial species (from Al Si56 to Fe161 Ni Mn73 etc) For example

Loss recently reported that through electrical manipulation of the molecular redox

potential the two localized spins of the interstitial atoms in a cage can be coupled in

such a way a two-qubit gates and qubit readout can be implemented162

Related to the idea of manipulating the spin state of the electrons of the interstitial

atom even just for oxygen at the central position as reported herein alternating oxygen

vacancies have been reported to play an important role in the superconducting properties

of peroovskite structures Such related structures have been synthesized67 76 but not

shown to be superconductors but this is certainly an attractive direction for future work

As early as 1996163 efforts to substitute one vertex tungsten with Ti Zr etc in

[W6O19]2- by hydrolysis have achieved success if ldquovice versardquo is feasible introducing

hetero metal atoms to the Zr sites in the reported structure will likely bring new

piezoelectric materials since the Pb(ZrxTi1-x)O3 (PZT)64 66 164 has been well applied as a

piezoelectric and it shares much structural similarities with the newly studied crystal

There may exist various ways for them to be linked into 2D or 3D networks as

discussed in the last session One analogous 3D structure found in α-ZrW2O862 63 leads

to its distinctive negative thermal expansion property Therefore if [iOZr6(micro-OH)12(oxo-

O)6]2- can be re-assembled into a 3D network it could be expected to exhibit some

similar novel thermal properties

81 Related to the linking strategy discussed above using bidentate ligands as the

spacers creates some supramolecule hierarchy structures Examplified in Figure 3-13

such a design is employed to build enatio-selective oxidation catalysts59 106

Figure 3-13 Proposed linking modes enabling the Zr6 super lattice with chiral properties105

357 How likely could the ligands be alkyl groups

As previously mentioned the reactions were originally designed to produce Zr-C

clusters When the hexanuclear [iOZr6(OH)12(O)6]2- cluster was identified from X-ray

diffraction itrsquos reasonable to question if it contains motifs of Zr6C8-12 or other related

82 zirconium carbide clusters relevant to Zr-Met-Cars10 This question arises even though

theoretical calculations have pointed out that Zr6C8 in octahedron symmetry is much less

stable than in D6h which is almost a ring-like structure165 Not mentioned is the fact that

there was no carbon dimer unit observed The polyalkyl zirconium cluster would be the

next to consider However polyalkyl metal complexes are notoriously low in thermal

stability and high air sensitivity Examples can be found in Ti(CH3)4 which undergoes

rapid decomposition above 0deg166 and W(CH3)6 which decomposes explosively167 at

room temperature With a sharp contrast crystals containing [iOZr6(OH)12(O)6]2- were

found although the system was exposed to ambient condition during ~15 years and for

~3 weeks multiple cycles of sonicationdrying to optimize the crystallinity These facts

attest it being highly air-stable

Nevertheless considering the limited resolution of X-ray to distinguish carbon

and oxygen itrsquos very appealing to give an in-depth inspection to evaluate the possibility

of formation of Zr-C based hexanuclear clusters

Evaluation of having carbene andor carbyne168 at both axial or terminal positions

is given as follows Classified on different spin states (annotated as S Table 38) there

are two types of carbenes carbynes Fischer type and Schrock type59 169-171 They very

distinctly render their different chemical properties A summary of the related properties

of both types is given in Table 38 No intermediate type is considered which requires a

substituted halogen group on carbon in the form of M=C(halogen)2172 such a large atom

(larger than H) could have had been easily recognized in the X-ray diffraction data if any

were present

83

Table 3-7 Summary of related properties of Fischer and Schrock carbenes and carbynes

Terminal carbenes are very reactive easily undergo thermal decomposition and

oxidative cleavage by air so that they are rarely isolated59 173 Moreover when a M=C

motif is identified usually there are OR bulky R (tertiary alkyl) PRn or NRn groups

(good π donors)59 on carbon and CO (π acceptor for Fischer type) and Cl Cp PRn (π

donor for Schrock type) on metal atoms Experimentally their transient existence is

usually captured by H-NMR and the structure is deduced such as in the case of Ti=CH2

in (Cp2)(Me2AlCl)(Ti)=CH2174 Crystallographic data is found to be very scarce only

four such reports are available including Cl3(PPh3)Ta=CH(CMe3) (with Ta=C distance at

1898(2)Aring) (Cl)(CO)(PPh3)Os=CH2 (Os=C at 1856 Aring(12)175 ) O=W=CHCMe3) (W=C

at 188 Aring 115) and [(Cp)(PMe3)Zr=CHO]2 (Zr=C at 2117(7)Aring176) The fact that not only

are they larger than the 1687Aring in the reported structure but they also lack of CO Cl

PRn etc making the hypothesis of terminal Zr=C group not mechanistically plausible

Terminal carbynes again are very reactive and would form toward carbene

type59 It was summarized that MequivC formed with second and third row metals are in the

range of 175 ndash 190Aring59 in length Only one report is found where the reported MoequivC

84

bond length is 1713(9)177 this is in the form of a [MoequivC]- fragment where Mo is

stabilized by three very exotic and bulky ligands [N(tBu)Ar] which adopt a propeller

motif with the aryl rings π stacked on one side and the tert-butyl groups on the other side

forming a protective ldquopocketrdquo about the [MoequivC]- Again the bond length is generally

longer than 1687 Aring (see Table 3-7) and the metal is in lack of required protecting

ligands This hypothesis is not well supported

Likewise the Zr-(CH2)-Zr motif hardly has mechanistic or crystallographic

support as well They are frequently postulated based on 1H-NMR measurements174 as

being the transient and energetic intermediate states 2micro-bridging carbynes as

hypothesized in Zr-(CH)-Zr are unsaturated very reactive and transient59 178 forming

3micro-bridging with three metals (face-bridged) to be stabilized59 Spectroscopic study

suggests that when no M-M bond is present the M-CH2-M angle is close to (but smaller

than) 109deg when M-M is found the M-CH2-M angle is 75deg to 85deg59 None of these untis

is observed in the diffraction map which shows the Zr-microX-Zr angle has an average value

of 116deg being close to 120deg for the sp2 hybridization It is supposed to be slightly

affected by the lone pair electron repulsion which likely comes from OH

The presumed Zr-alkyl fragments is ruled out by the above detailed discussion

Globally speaking the structure refinement exhibits obviously larger deviation when O is

replaced by C such as for [iCZ6C12O6] the R (defined in Table 34) value increases to be

45 Moreover the thermal ellipsoids and the residual charge exhibit much abnormal

85 values for [iCZ6C12O6] Nevertheless all possible combinations for a [(CO)Zr6L12X6]2-

cluster anion are summarized in Table 39 below

All Possible Zr-alkyl Combinations in a [(CO)Zr6L12X6]2- skeleton Panel I Zr6C Core

briding axial LX LX Fischer Type LX w Zr(IV)w Zr(III)Schrock Type LX w Zr(IV)w Zr(III) TotalwC(-IV)w C(-IV) chargew C(-IVcharge )w C(-IV) Ion

L12 X6 massmasscharge charge total total total charge charge total total total MassAll R CH CH 13 13 -4 -10 -1 -3 -30 -10 -16 792CH2 CH2 14 14 -10 -16 -2 -2 -36 -16 -22 810CH CH2 13 14 2 -4 -1 -2 -24 -4 -10 798CH2 CH 14 13 -16 -22 -2 -3 -42 -22 -28 804

OH+ROH CH 17 13 -4 -10 -1 -3 -30 -10 -16 840OH CH2 17 14 2 -4 -1 -2 -24 -4 -10 846CH OH 13 17 2 -4 -1 -1 -18 2 -4 816CH2 OH 14 17 -10 -16 -2 -1 -30 -10 -16 828

O + RO CH 16 13 -16 -22 -2 -3 -42 -22 -28 828O CH2 16 14 -10 -16 -2 -2 -36 -16 -22 834

CH O 13 16 -4 -10 -1 -2 -24 -4 -10 810CH2 O 14 16 -16 -22 -2 -2 -36 -16 -22 822

Panel II Zr6O Corebriding axia

-1 -2 -24-2 -1 -30-1 -1 -18-2 -2 -36

-1 -2 -24-1 -1 -18-1 -1 -18-2 -1 -30

-2 -2 -36-2 -1 -30-1 -2 -24-2 -2 -36

l LX LX w Zr(IVFischer Type LX )w Zr(III)Schrock Type LX w Zr(IV)w Zr(III) TotalwO(-II) w O(-II) charge w O(-II) w O(-II) Ion

L12 X6 mascharge

smasscharge charge total total total charge charge total total total MassAll R CH CH 13 13 -2 -8 -1 -3 -30 -8 -14 794CH2 CH2 14 14 -8 -14 -2 -2 -36 -14 -20 812CH CH2 13 14 4 -2 -1 -2 -24 -2 -8 800CH2 CH 14 13 -14 -20 -2 -3 -42 -20 -26 806


O + RO CH 16 13 -14 -20 -2 -3 -42 -20 -26 830O CH2 16 14 -8 -14 -2 -2 -36 -14 -20 836

CH O 13 16 -2 -8 -1 -2 -24 -2 -8 812CH2 O 14 16 -14 -20 -2 -2 -36 -14 -20 824

-1 -2 -24-2 -1 -30-1 -1 -18-2 -2 -36

-1 -2 -24-1 -1 -18-1 -1 -18-2 -1 -30

-2 -2 -36-2 -1 -30-1 -2 -24-2 -2 -36

Table 3-8 Summary of all possible ligands combinations The resultant charge status and mass are highlighted in colored areas

86

From such a thorough survey one can tell for sure that none of the combinations

can simultaneously satisfy the charge status (light blue and light yellow-shaded are) and

mass (light green shaded area) detected from MALDI (as singly-protonated species in

principle)

Lastly the diffraction data indicates the existence of intense hydrogen bonding

networks which are less likely to form between hydrogen and carbon atoms

In conclusion even without elemental analysis performed the formation of

possible ldquozircono-alkylsrdquo can be ruled out from evaluations of chemical stability

structural parameters charge status and molecular stoichiometry

358 Repeatability and Future Work

Dedicated endeavor of re-producing the same [iOZr6(OH)12(O)6]middot2[N(nBu)6]

cluster-based crystal had been carried out intensely unfortunately without success as yet

Taking the original crystal growth condition into consideration a certain length of

time might be critical for both cations and anions to form The route in which the highly

ordered tertiary amine cation N(Bu)4+ generated in-situ and ldquoall-by-its-ownrdquo is unclear

The construction of the hierarchal structure composed of multinuclear broth from metal

atoms and from the non-metal atoms is supposed to ldquoself-assemblerdquo72 and thus it might

just need a very lengthy nucleation period without perturbation

For purpose of reproducing the findings experiments were conducted where the

choice of the cations was made strictly the same as in [iOZr6(OH)12(O)6]middot2[N(nBu)6]

87 being added ex-situ in form of N(nBu)4(PF6) Such a recipe did not prove to be the

ldquooptimizedrdquo one Because having the bulky cation in the starting materials reaction

products were often found to become very viscous sensitive to solubility resistant to the

formation of crystals (often condensed in glassy solid) and temperature sensitive All of

these properties are not surprising giving the ionic liquid characters of N(Bu)4+179 180

However these features severely impede the single crystal growth which requires

sufficient quantity and quality Previous experiments where the crystals were discovered

did not exhibit much viscosity till the later stage Such time elapse is supposed to be

critical to provide enough ldquowaitingrdquo time for the simultaneous evolution of

[iOZr6(OH)12(O)6]2- (or other similar 3D lattices) and N(Bu)4+ Complications occurred

by including P and F in the starting materials as well because both of them are both

nucleophilic59 and could competitively catch Zr (or Zr clusters) Phases identified by P-

XRD often proved this point

All aforementioned conditions made the reproduction unsuccessful Eventually

time might make difference Alternatively only if it were not for repeating rather for a

new project many other simple inorganic caions could have been tried45

Nevertheless for future work an elemental analysis should be performed

whenever the condition allows even the formulation of [iOZr6(OH)12(O)6]2- is made with

high confidence Molecular orbital calculations are expected possibly through external

collaborations 1H-NMR was missed accidentally which also well demonstrates how

adversely could the personnelrsquos limited experience and biased ldquoanticipationrdquo (toward Zr-

88 Met-Car in this case) effect the scientific investigation It should be determined

whenever the phase purity could be confirmed by powder-XRD

Trials with other metal carbides such as TiC and VC provided interesting

comparison (unpublished results) but yet cluster-containing structural motifs were found

More investigation is planned for future work

36 Conclusions

Through exquisite analysis from many aspects it can be concluded that the

[iOZr6(OH)12(O)6]2- formulation is made with high confidence Despite the impeded

reproducibility the reported lengthy cluster preparation successfully brings a new

window to appreciate the diversity in the transition metal chemistry For example

terminal oxo-Zr motif has been rarely seen while it plays an important role in stabilizing

the reported structure It is highly stable in air structurally reflected by the impressively

short metal-oxygen distance forming a solid base to be used as the building blocks for

new cluster-assembled materials

While starting largely from a scheme pointing toward the synthesis of metal-

carbon clusters the reported hexanuclear zirconium cluster stabilized by oxo- and

hydroxyl ligands in high symmetry may be taken as the first real polyoxometalates (or

ldquopolyhydroxidesrdquo) with metal solely from group IVB42 andor as the first fully oxidized

Corbett type ion The preparation method reported is rather simple in setup and

environment friendly in terms of all reacting reagents are sealed in an autoclave vessel

Compared with the convention solid state synthesis employed in those well-known

89 polyoxometalates or halide-Zr6 clusters it requires a much amiable condition which

could greatly reduce the cost The starting materials reported herein could only be a

simplified and fortuitous situation where only ternary components ZrC toluene and

pyridine were employed but such simple combination of the starting material is typical

for experiments involving hydrosolvothermal synthesis

Exploring hydrosolvothermal synthesis by using resource largely outside the

authorrsquos research group has been very challenging but a good learning process The

reported results prove it to be a very valuable platform potentially bridging the gap

between gas-phase cluster science and liquid-phase synthesis of unique cluster complex

either as one isolated broken-down unit or as building blocks being part of the assembled

super lattice Expansion of operations in the organic environment in terms of the

potential coordination ligands hydrothermal solvent and those for crystal treatment is

anticipated to bring more opportunities to discover more structures which could

eventually lead to the isolation of Met-Cars

It always takes more courage and stronger scientific evidence to prove something

new If the hypothesized ldquozircono-carbanecarbenecarbynerdquo become established as the

true nature of the compound discussed herein it only opens a more fascinating field in

the modern chemistry considering its high thermal stability under ambient condition for

a 2 year period also with various manipulations during the crystal growth


The author gratefully acknowledges the following persons for their assistance

Dr Jin and Dr Corbett provided valuable suggestions during the manuscript

proofreading

The reactions were allowed to be carried out in Dr Komarneni and Dr Mallouk

Lab space with assistant from the group members Dr Lu Dr Gao and Anna in setting

up the furnace respectively

Dr Ugrinovrsquos valuable input in solving the structure and discussion in preparing

the manuscript

Dr Mallokrsquos insightful suggestion and inspiring encouragement

Dr Senrsquos generous offer with some unusual organic solvent and access for the

glove box for Met-Car synthesis

Dr Dickeyrsquos insightful discussion on P-XRD and suggestion on SAXDF

Dr Hemantrsquos assistance in diffraction data collections and the access of the

Single Crystal Diffraction Facility

Mr J Muller (for ESI-MS) and Heikeirsquos (for MALDI-MS)rsquos assistance with all

resource in the Mass Facility

Dr Bruce and Dr Bruce (Anne)rsquos assistance in MALDI-MS measurement and the

Mass Core Facility at Hershey Medical School

Dr Kobayashirsquos help and discussion on P-XRD in the facility housed in

DrMallouk Lab space

91 DrWinograd and DrPetersonrsquos group memebersrsquo friendly allowance to the

sonicator and rotary evaporator

Financial support from AFOSR (2005 to 2006 No F49620-01-0122) MURI

(2007 No W911NF-6-1-28) as well as private support from Dr Li (2007) are greatly

appreciated

38 References

1 Ayers T M Fye J L Li Q Duncan M A Journal of Cluster Science 2003

14 (2) 97-113

2 Toleno B J Lyn M E Castleman A W Abstracts of Papers of the American

Chemical Society 1998 215 U180-U180

3 Selvan R Pradeep T Chemical Physics Letters 1999 309 (3-4) 149-156

4 Dance I Wenger E Harris H Chem Eur J 2002 8 (15) 3497-3511

5 Kratschmer W Lamb L D Fostiropoulos K Huffman D R Nature 1990

347 (6291) 354-358

6 Dresselhaus M S Dresselhaus G Eklund P C Journal of Materials Research

1993 8 (8) 2054-2097

7 Haufler R E Conceicao J Chibante L P F Chai Y Byrne N E Flanagan

S Haley M M Obrien S C Pan C Xiao Z Billups W E Ciufolini M A

Hauge R H Margrave J L Wilson L J Curl R F Smalley R E Journal of


8 Chai Y Guo T Jin C M Haufler R E Chibante L P F Fure J Wang L

H Alford J M Smalley R E Journal of Physical Chemistry 1991 95 (20) 7564-

7568

92 9 Deng H T Kerns K P Castleman A W Journal of the American Chemical

Society 1996 118 (2) 446-450

10 Guo B C K K P Castleman A W Jr JACS 1993 115 (16) 7415

11 Sakurai H Castleman A W Journal of Chemical Physics 1999 111 (4) 1462-

1466

12 Liu P Rodriguez J A Journal of Chemical Physics 2003 119 (20) 10895-

10903


5423

14 Liu P Rodriguez J A Hou H Muckerman J T Journal of Chemical

Physics 2003 118 (17) 7737-7740


2004 108 (49) 18796-18798

16 Liu P Rodriguez J A Muckerman J T Journal of Chemical Physics 2004

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Chemical 2005 239 (1-2) 116-124


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19211-19214


Science 1993 260 (5105) 195-196

21 Easom K A Klabunde K J Sorensen C M Hadjipanayis G C Polyhedron

1994 13 (8) 1197-1223

22 Cheng K W Tang M Chen Y P Fluid Phase Equilibria 2003 214 (2) 169-

186

23 Cundy C S Cox P A Microporous and Mesoporous Materials 2005 82 (1-

2) 1-78

93 24 Sun C Y Liu S X Xie L H Wang C L Gao B Zhang C D Su Z M

Journal of Solid State Chemistry 2006 179 (7) 2093-2100

25 Li D Wu T Zhou X P Zhou R Hitang X C Angewandte Chemie-

International Edition 2005 44 (27) 4175-4178

26 Michailovski A Patzke G R Chemistry-a European Journal 2006 12 (36)

9122-9134

27 Zhang X M Coordination Chemistry Reviews 2005 249 (11-12) 1201-1219

28 Komarneni S Current Science 2003 85 (12) 1730-1734

29 Rajamathi M Seshadri R Current Opinion in Solid State amp Materials Science

2002 6 (4) 337-345

30 Guo B C Wei S Purnell J Buzza S Castleman A W Science 1992 256

(5056) 515-516

31 Cushing B L Kolesnichenko V L OConnor C J Chemical Reviews 2004

104 (9) 3893-3946

32 Hanrath T Korgel B A Advanced Materials 2003 15 (5) 437-440

33 Wang X Zhuang J Peng Q Li Y D Nature 2005 437 (7055) 121-124

34 Hagrman D Hagrman P J Zubieta J Angewandte Chemie-International

Edition 1999 38 (21) 3165-3168

35 Welch E J Crawford N R M Bergman R G Long J R Journal of the

American Chemical Society 2003 125 (38) 11464-11465

36 Chang Y H Chin C W Chen Y C Wu C C Tsai C P Wang J L

Chiu H T Journal of Materials Chemistry 2002 12 (8) 2189-2191

37 Sherman A R ldquoPyridinerdquo in e-EROS (Encyclopedia of Reagents for Organic

Synthesis) J Wiley amp Sons New York 2004

38 McHugh M A Krukonis V J Supercritical Fluid Extraction 2nd Edition

Elsevier 1994

39 Emirdag M Schimek G L Kolis J W J Chem Soc Dalton Trans 1999

1531-1532

40 DrMallouk In 2007

94 41 Keggin J F Proc Roy Soc A 1934 144 851

42 Day V W Eberspacher T A Klemperer W G Park C W JACS 1993 115

8469

43 Cotton F A Murillo C A Bochmann M Advanced Inorganic Chemistry 6th

Edition Wiley-Interscience 1999

44 Ziebarth R P Corbett J D Journal of the American Chemical Society 1985

107 (15) 4571-4573


109 (16) 4844-4850

46 Ziebarth R P Corbett J D Journal of the Less-Common Metals 1988 137 (1-

2) 21-34

47 Ziebarth R P Corbett J D Journal of Solid State Chemistry 1989 80 (1) 56-

67

48 Ziebarth R P a C Inorganic Chemistry 1989 28 626

49 Corbett J D Pure and Applied Chemistry 1992 64 (10) 1395-1408

50 Corbett J D Journal of Alloys and Compounds 1995 229 (1) 10-23

51 Corbett J D Journal of the Chemical Society-Dalton Transactions 1996 (5)

575-587

52 Corbett J D Inorganic Chemistry 2000 39 (23) 5178-5191

53 Shen J Y Hughbanks T Journal of Physcal Chemistry A 2004 108 350

54 Ziebarth R P C J D Acc Chem Res 1989 22 (7) 256

55 Smith J D Corbett J D Journal of the American Chemical Society 1984 106

(16) 4618-4619


(8) 1927-1934

57 Smith J D C J D JACS 1985 107 (5704)

58 Lehmann J A G-A E Coronado and D Loss Nature Nanotechnology 2007 2

312

95 59 Crabtree R H The Organometallic Chemistry of the Transition Metals 4th

Edition Wiley-Interscience 4 edition 2005 May 5

60 YB Lei C N S a F C A Inorganic Chemistry 1996 35 (10) 3044

61 Kuhl O Blaurock S Sieler J Hey-Hawkins E Polyhedron 2001 20 (17)

2171-2177

62 Goodwin A L Calleja M Conterio M J Dove M T Evans J S O Keen

D A Peters L Tucker M G Science 2008 319 (5864) 794

63 Mary T A Evans J S O Vogt T Sleight A W Science 1996 272 90

64 Liu W J B Zhu W Applied Physics Letters 2000 77 (7) 1047

65 Rouquette J H J Bornand V Pintard M Papet Ph Bousquet C Konczewicz L

Gorelli FAHull S Phys Rev B 2004 70 014108

66 Grinberg I Cooper V R Rappe A M Physical Review B 2004 69 (14)

67 Wu E J Pell M A Genin H S Ibers J A Journal of Alloys and

Compounds 1998 278 (1-2) 123-129

68 Lo V C Journal of Applied Physics 2002 92 6778

69 Klemperer W G created this picture and has permission to release to public

domain In

70 Hughbanks T Journal of Alloys and Compounds 1995 229 (1) 40-53

71 Hughbanks T Progress in Solid State Chemistry 1989 19 (4) 329-372

72 Gray T G Coordination Chemistry Reviews 2003 243 (1-2) 213-235

73 Zhang J Corbett J D Inorganic Chemistry 1991 30 (3) 431-435

74 Zhang J Corbett J D Zeitschrift Fur Anorganische Und Allgemeine Chemie

1991 598 (7-8) 363-370

75 Zhang J Ziebarth R P Corbett J D Inorganic Chemistry 1992 31 (4) 614-

619



78 Payne M W Corbett J D Journal of Solid State Chemistry 1993 102 (2)

553-556

96 79 Sun D Hughbanks T Inorganic Chemistry 1999 38 (5) 992-997

80 Sun D Hughbanks T Inorganic Chemistry 2000 39 (9) 1964-1968

81 Xie X Hughbanks T Solid State Sciences 1999 1 (7-8) 463-471

82 Xie X B Hughbanks T Angewandte Chemie-International Edition 1999 38

(12) 1777-1779

83 Xie X B Hughbanks T Inorganic Chemistry 2000 39 (3) 555-561


85 Xie X B Jones J N Hughbanks T Inorganic Chemistry 2001 40 (3) 522-

527

86 Xie X B Reibenspies J H Hughbanks T Journal of the American Chemical

Society 1998 120 (44) 11391-11400

87 Runyan C E Hughbanks T Journal of the American Chemical Society 1994

116 (17) 7909-7910

88 Tian Y C Hughbanks T Inorganic Chemistry 1995 34 (25) 6250-6254

89 Tian Y C Hughbanks T Zeitschrift Fur Anorganische Und Allgemeine

Chemie 1996 622 (3) 425-431

90 Chen L F Cotton F A Inorganica Chimica Acta 1997 257 (1) 105-120

91 Chen L F Cotton F A Journal of Cluster Science 1998 9 (1) 63-91

92 Chen L F Cotton F A Klooster W T Koetzle T F Journal of the


93 Chen L F Cotton F A Wojtczak W A Inorganic Chemistry 1996 35 (10)

2988-2994

94 Chen L F Cotton F A Wojtczak W A Inorganica Chimica Acta 1996 252

(1-2) 239-250


4047-4054

96 Fry C G Smith J D Corbett J D 1986 25 117

97 Long G J Hautot D Mohan A Hughbanks T Xie X B Grandjean F

Journal of the American Chemical Society 1998 120 (46) 12163-12164

97 98 APEX II Manufacture SMART and SAINT software package Brucker AXS

99 Sheldrick G M SHELXTL Bruker-Nonius AXS Madison WI 2001

100 Manura J J Manura D J Isotope Distribution Calculator and Mass Spec

Plotter Scientific Instrument Services Inc 1027 Old York Rd Ringoes NJ 08551

1996-2003

101 Sanger I Lerner H W Bolte M Acta Crystallographica Section E-Structure

Reports Online 2004 60 O1847-O1848

102 Mass Facility U P Sample Submission Forms In 2007

103 Meng T Z Wang C W Wang S Y Journal of Physics Condensed Matter

2006 18 10521

104 Atkins P de Paula J The Elements of Physical Chemistry 4th ed W H

Freeman 2005

105 Reza M Y Matsushima H Koikawa M Nakashima M Tokii T

Polyhedron 1999 18 (6) 787-792

106 Reza M Y Matsushima H H Koikawa M Nakashima M Tokii T

Bulletin of the Chemical Society of Japan 1998 71 (1) 155-160

107 Chen C T Gau H M Journal of Organometallic Chemistry 1995 505 (1)

17-21

108 Palmer E J Synthesis characterization and density functional theory

investigations of tris-cyclopentadienyl compounds of zirconium and hafnium The Ohio

State University 2005

109 Atwood J L Rogers R D Bynum R V Acta Crystallographica Section C-

Crystal Structure Communications 1984 40 (NOV) 1812-1814

110 Wolczanski P T Threlkel R S Santarsiero B D Acta Crystallographica

Section C-Crystal Structure Communications 1983 39 (OCT) 1330-1333

111 Chen S G Yin Y S Wang D P Journal of Molecular Structure 2004 690

(1-3) 181-187

112 Howard C J Hill R J Reichert B E Acta Crystallographica Section B-

Structural Science 1988 44 116-120

98 113 Zhao X Y Ceresoli D Vanderbilt D Physical Review B 2005 71 (8)

114 Favre G Brennetot R Chartier F Vitorge P International Journal of Mass

Spectrometry 2007 265 (1) 15-22

115 Wengrovius J H Schrock R R Organometallics 1982 1 (1) 148-155

116 Gao L Ugrinov A Castleman A W J Isolation and Structural

Characterization of [Zr6iO(OH)12O6]bull2[N(Bu)4] In 2008

117 Hillenkamp F Peter-Katalinic J MALDI MS A Practical Guide to

Instrumentation Methods and Applications 1 edition ed Wiley-VCH 2007

118 Pickett C J Titanium Zirconium and Hafnium Wiley-VCH Verlag GmbH amp

Co KGaA 2007

119 Stapels M D F B D Analytical Chemistry 2004 76 (18) 5423

120 Kohler F H Schell A Rapid Coomunications in Mass Spectrometry 1999 13

(12) 1088

121 Dyson P J Hearley A K Johnson B F G Langridge-Smith P R R

Mclndoe J S Inorganic Chemistry 2004 43 4962


Mclndoe J S Journal of Cluster Science 2001 12 (1)

123 Di Marco V B Bombi G G Mass Spectrometry Reviews 2006 25 (3) 347-

379

124 Moraes M C B Brito-Neto J G A Juliano V F do Lago C L

International Journal of Mass Spectrometry 1998 178 (3) 129

125 Note In Corbett mode few report mentioned any charge status but the formal

oxidation state Zr(III) (assuming the interstitial elements bearing their most reduced

oxidation state as same as in other hydrides borides nitrides carbidess) can account for

all charge status of reported Z6-halide clusters In 2008

126 Fuchs J Freiwald W Hartl H Acta Crystallographica Section B-Structural

Science 1978 34 (JUN) 1764-1770

127 Allcock H R Bissell E C Shawl E T Inorganic Chemistry 1973 12 (12)

2963-2968

99 128 Huheey J E K EA Keiter R L Inorganic Chemistry Principles of Structure

and Reactivity (4th Edition) Prentice Hall 4 edition 1997

129 Dexter D D Silverton J V Journal of the American Chemical Society 1968

(3589)

130 Hollingshead J A McCarley R E JACS 1990 112 7402-7403

131 Zhao J W Zhang J Zheng S T Yang G Y Inorganic Chemistry 2007 46

(26) 10944

132 Chevrel R M S Pringent J Journal of Solida State Chemistry 1971 3 515

133 Fenske D Grissinger A Loos M Magull J Zeitschrift Fur Anorganische

Und Allgemeine Chemie 1991 598 (7-8) 121-128

134 Kickelbick G Schubert U Chemische Berichte-Recueil 1997 130 (4) 473-

477

135 Kickelbick G Schubert U Journal of the Chemical Society-Dalton

Transactions 1999 (8) 1301-1305

136 Kickelbick G Wiede P Schubert U Inorganica Chimica Acta 1999 284 (1)

1-7

137 Kohler J Tischtau R Simon A Journal of the Chemical Society-Dalton

Transactions 1991 829-832

138 Reckeweg O Meyer H J Simon A Zeitschrift Fur Anorganische Und

Allgemeine Chemie 2002 628 (5) 920-922

139 Simon A SchnerinHg Wohrle H Schafer H Zeitschrift Fur Anorganische

Und Allgemeine Chemie 1965 339 (3-4) 155-amp

140 Brnicevic N Mustovic F McCarley R E Inorganic Chemistry 1988 27 (25)

4532-4535

141 Brnicevic N Sirac S Basic I Zhang Z H McCarley R E Guzei I A

Inorganic Chemistry 1999 38 (18) 4159-+

142 Hughes B G Meyer J L Fleming P B McCarley R E Inorganic

Chemistry 1970 9 (6) 134

100 143 Planinic P Rastija V Sirac S Vojnovic M Frkanec L Brnicevic N

McCarley R E Journal of Cluster Science 2002 13 (2) 215-222

144 Artemkina S B Naumov N G Virovets A V Oeckler O Simon A

Erenburg S B Bausk N V Fedorov V E European Journal of Inorganic Chemistry

2002 (5) 1198-1202

145 Mironov Y V Yarovoi S S Naumov D Y Simon A Fedorov V E

Inorganica Chimica Acta 2007 360 (9) 2953-2957

146 Aufdembrink B A McCarley R E Journal of the American Chemical Society

1986 108 (9) 2474-2476

147 Brnicevic N Basic I Hoxha B Planinic P McCarley R E Polyhedron

2003 22 (12) 1553-1559

148 Hogue R D McCarley R E Inorganic Chemistry 1970 9 (6) 1354-amp

149 Paskach T J Hilsenbeck S J Thompson R K McCarley R E Schrader G

L Journal of Alloys and Compounds 2000 311 (2) 169-180

150 Paskach T J Schrader G L McCarley R E Journal of Catalysis 2002 211

(2) 285-295

151 Bos M E Tetra-n-butylammonium Hydroxide in Encyclopedia of Reagents for

Organic Synthesis J Wiley amp Sons New York 2004

152 Rossberg M etal Chlorinated Hydrocarbonsrdquo in Ullmannrsquos Encyclopedia of

Industrial Chemistry 2006 John Wiley-VCH Weinheim 2006

153 Wikipedia 124-Trichlorobenzene

154 Note ExcisionExcising have specific meanings in the report herein to indicate

the process of isolating one building unit from the original 3D network because Corbett

iosn are famous for etheir diversity in linking into condensed cluster compounds which

is the prototype of what we refer now cluster assemblied material In 2008

155 Reiners P W Low-temperature thermochronology techniques interpretations

and applications Mineralogical Society of America 2005

156 Tian G Yuan H M Mu Y He C Feng S H Organic Letters 2007 9 (10)

2019

101 157 Pool J A Scott B L Kiplinger J L Chemical Communications 2005 2591

158 Guo B C Castleman A W Journal of the American Chemical Society 1992

114 (15) 6152-6158

159 Guo B C Castleman A W Journal of the American Society for Mass

Spectrometry 1992 3 (4) 464-466

160 F Albert Cotton C A M Manfred Bochmann Advanced Inorganic Chemistry

6th Edition Wiley-Interscience March 30 1999

161 Zhang J Corbett J D Journal of Solid State Chemistry 1994 109 (2) 265-

271

162 J Lehmann A G-A E Coronado and D Loss Nature Nanotechnology 2007 2

312

163 Clegg W Elsegood M R J Errington R J Havelock J Journal of the

Chemical Society-Dalton Transactions 1996 (5) 681-690

164 Rouquette J Haines J Bornand V Pintard M Papet P Bousquet C

Konczewicz L Gorelli F A Hull S Phys Rev B 2004 70 014108

165 Ge M F Feng J K Yang C Li Z R Sun C C International Journal of

Quantum Chemistry 1999 71 (4) 313-318

166 Clauss K Beermann C Angewandte Chemie-International Edition 1959 71

(19) 627-627

167 Shortland A J Wilkinson G J Chem Soc Dalton Trans 1973 872

168 Note The distance of 168Aring between Zr and axial ligand is substantially longer

than Zr-C single bond length (235Aring in carbide) which rule out the consideration of Zr-C

single bond In 2008

169 Schrock R R Journal of the Chemical Society-Dalton Transactions 2001 (18)

2541-2550

170 Herndon J W Coordination Chemistry Reviews 2004 248 (1-2) 3-79

171 Herndon J W Coordination Chemistry Reviews 1999 181 177-242

172 Brothers P J Roper W R Chemical Reviews 1988 88 (7) 1293-1326

102 173 Hayes J C Jernakoff P Miller G A Cooper N J Pure and Applied

Chemistry 1984 56 (1) 25-33

174 Tebbe F N Parshall G W Reddy G S Journal of the American Chemical

Society 1978 100 (11) 3611-3613

175 Bohle D S Clark G R Rickard C E F Roper W R Shepard W E B

Wright L J Journal of the Chemical Society-Chemical Communications 1987 (8) 563-

565

176 Barger P T Santarsiero B D Armantrout J Bercaw J E Journal of the


177 Peters J C Odom A L Cummins C C Chemical Communications 1997

(20) 1995-1996

178 Boag N M Green M Mills R M Pain G N Stone F G A Woodward

P Journal of the Chemical Society-Chemical Communications 1980 (23) 1171-1173

179 Babai A Mudring A V Zeitschrift Fur Anorganische Und Allgemeine Chemie

2006 632 (12-13) 1956-1958

180 Lin I J B Vasam C S Journal of Organometallic Chemistry 2005 690 (15)

3498-3512

103 Chapter 4

Studies on Small Monolayer Protected Gold Clusters (Au-MPCs) Ligand-core

Interactions Spontaneous Growth and Self-Assembling

41 Abstract


via multiple techniques including the Electrospray Ionization Mass Spectrometry (ESI-

MS) Ultraviolet-Visible Spectroscopy (Uv-Vis) Nuclear Magnetic Resonance (NMR)

for solution phase and Transmission Electron Microscopy (TEM and High-Resolution

TEM) for the condensed phase In particular undeca- dodeca- and trideca-gold clusters


predominant and persist in solution for months while they gradually and spontaneously

grow into a monomial tridecagold clusters series The unique preferred ligands

combination depp along with Cl is discussed in terms of the ligand-core interaction and

the closed-shell electronic configurations of the Aun (n=11-13) cores which enables them

to serve as building units for larger cluster-assembled nanoparticles and form Self-

Assembled Arrays (SAAs) discovered by TEM observation Such spontaneous growth

behavior and the final SAAs observation are correlated by cluster-packing modes

following ldquomagic numbersrdquo with ~7 shells of clusters proposed to be those in SAAs

104 42 Introduction

Nanostructured materials are gaining wide attention in nanotechnology because

materials in nanometer size regime display what could be broadly applicable size-

dependent optical electronic and chemical properties1-5 Monolayer-protected clusters

(MPCs and defined as ldquonanoparticles composed of inorganic cores with monolayer shells

of organic ligandsrdquo6) are of particular interests for developing nanoassemblies for

applications in material preparation7-9 biomedical treatment10-12 and device fabrication13

14 The surface-protecting ligands not only assist with tunable solubility based on the

desired media for analyses or for applications they also fill in the active sites on the

surface of clusters thereby lowering the core surface energy and often sterically

stabilizing the cluster dispersion15 This method has brought unprecedented control to

producing the resulting nanocrystals in terms of composition16 crystalinity17 core size18

and size dispersity19 which offers exciting opportunities for the rational design of novel

materials

It has been an appealing goal for the author to introduce gaseous clusters to the

condensed phase20 through ligand protection methods21 22 Nanoscale gold MPCs were

chosen as the model case because they have been the subject of increasing attention for

the past decade due to their unique optical and electrochemical properties23-29 structural

biological applications30-33 as well as potential catalytic properties34 35 since Brust et al36

introduced a simple method for the preparation of gold nanoparticles stabilized with

various thiol-containing ligands This family of clusters has been primarily surface-

passivated by thiolate groups as well as by several other ligands such as amines37

105 thioethers38 and phosphines39 Among them bidentate phosphine ligands were chosen

based on previous suggestions that size-selectivity can be improved by varying the M in

PR2(CH2)MPR2 34 35 and the ligandsrsquo electronic and steric properties can be altered over

the wide range by varying the R groups40 thus influencing the core-ligand interactions

(vide infra)

Mingos and Smits had a series of early successes in characterizing the crystal

structures of phosphine-protected gold clusters in the solid state through X-ray

crystallography and NMR41-44 which have been well summarized45 46 However except

for very limited number of recent successes24 47 48 related structural studies have been

limited by getting sufficient quality of the crystals49 andor impeded analysis50 on the

labile rapidly exchanging (on the NMR timescale at room temperature6 51) ligands

Alternative structural determination on these nanoclusters can be afforded by the

extended X-ray absorption fine structure and advanced electron microscopic

techniques52 53 but with limited facility access as well as the ldquoensemble-averaged

informationrdquo6 54 Electrospray Ionization Mass Spectrometry (ESI-MS or tandem ESI-

MSMS) techniques developed mainly by Fenn and coworkers55 allows simultaneous

observation of the distribution of the individual species in a solution phase at room

temperature and thus provides a very unique perspective in cluster studies especially for

the determination of the MPCsrsquo chemical composition and charge status with atomic

precision6 24 56 57 Moreover its high detection sensitivity (~50 microg 6) and minimal

sample treatment58 makes it unprecedented with respect to other analytical methods

106 Out of the common interests in studying the thermodynamickinetic behaviors of

gold MPCs in solution phase as well as the new instrumentation availability59 a

collaboration was initiated22 In the early study done by the authorrsquos collaborators

Bergeron et al60 revealed the distinctive degradation pathways of small gold MPCs

being identified through Collision-Induced Dissociations (CID) in ESI-MSMS

However subsequent attempts to compare the results of the fragmentation experiments to

theoretical calculation were constrained by difficulties encountered in modeling for the

moderately bulky ligands ie 13-bis(diphenlyphosphino)propane (dppp) and 15

bis(diphenlyphosphino)pentane in a system of 271 atoms and more Replacing the

phenyl groups with ethyl groups using the commercially available 13-

bis(diethylphosphino)propane (depp) ligand would reduce the total number of atoms by

80 while preserving the essential features particularly important was the preservation of

the three-carbon chain between the two P atoms of the bidentate ligand which we

believed would maintain the good size-selectivity of the synthesis However noting the

obvious differences between the ending groups in the two (focusing on dppp and depp)

ligands it is interesting to see how the electronic (of phenyl vs ethyl) and steric (bulky

vs small) differences might affect the clustersrsquo formation and distributions

Herein the author reports a series of experimental observations22 61 62 of small

gold MPCs in particular the undeca- dodeca- and trideca-gold clusters protected by depp

and halogen ligands ie [Au11-13(depp)4Cl2-4]+ on their stability-based distributions the

ligand-core interactions and a dynamic spontaneous growth behavior Such observations

are primarily from ESI-MS measurement also substantiated by other multiple techniques

107 including Ultraviolet-Visible absorbance spectroscopy (Uv-vis) Nuclear Magnetic

Resonance (NMR) and Transition Electron Microscopy (TEM and RT-TEM) with the

latter revealing a self-assemble array (SAA)63 structure on TEM grids The author

proposes a correlation between the spontaneous growth behaviors SAAs and the

observation in the scheme of cluster-packing modes following ldquomagic numbersrdquo64 65

43 Experimental

431 Materials and Preparation

The Au-MPCrsquos were synthesized according to the procedures described

previously60 Briefly the bidentate ligand 13-Bis(diethylphosphino)propane (depp) the

precursor AuClPPh3 and the reducing agent tert-butylamine borane complex (TBAB) (all

by Sigma-Aldrich used without further purification and shown in the middle orange-

framed box in Figure 4-1) were dissolved in a 115 ratio in a 11 solution of

CHCl3CH3OH (by Sigma-Aldrich and OmniSolv respectively high purity grade) with

~1mM1mM5mM concentrations

108

Figure 4-1 Diphosphine ligands involved in this report 1 3-Bis (diphenylphosphino) propane (dppp) and 1 3-Bis (diethylphosphino) propane (depp) and other starting materials The bottom box shows the potential degradation fragments P1 and P2 for short of depp induced upon oxidation (Note Ph = C6H5 Me = middotCH3 Et = C2H5 Pr =C3H7 as chemical convention)

109 Upon mixing of the reactant a light-yellowish color change was observed

immediately followed by a bright-pink color change after ~15 to 2 hours The reaction

solution was stirred under nitrogen gas (in-house supply Chemistry Research Building

University Park PA 2007) in a home-built glove bag overnight and the solution

gradually acquired a dark red color Depending on the stirring speed and consistency

this procedure could last for ~24 hours or longer based on the appearance of the

characteristic Uv-Vis absorption and the mass signals detections

Results collected were compared with those of previous studies60 in which dppp

(top box in Figure 4-1) ligands were used Oxidation of depp 66 which took place over

the period when shelf-lives of the product solutions were monitored formed two

fragments P1 and P2 which are schematically shown in the bottom box in Figure 4-1 as

well

432 Characterizations

Fresh Audepp solutions were characterized as soon as the sample was taken out

of the glove bag Residual solutions were stored in glass sample vials (66022-081 by

VWRreg) and analyzed periodically (thus referred to as ldquoagedrdquo sample later) for shelf-life

monitoring Solution aliquots were diluted according to the needs of different analytical

techniques specified in the following Results are regenerated in figures by Microsoftreg

Excel software unless otherwise specified

110 Diluted ( ~ x110 ~120 by 11 CH3OHCHCl3) Audepp solutions were used for

Uv-Vis spectra on a Lamda 950 spectrometer (Perkin Elmer with UV WinLab software

52) Absorption was measured under ambient conditions no special treatment such as

temperature control or inert gas sealing was taken

Audepp solutions were diluted in CH3OH (~ x120) for analysis via ESI-MS on

Waters LCT-API-MS Premier instrument calibrated at 100 to 4000 mz range (Figure

4-3a was taken on Micromass Quattro II59) Instrumental conditions are cone voltage at

30V desorption temperature at 300degC source block temperature at 120degC infusion rate

at 5~8 microLs through a Hamilton 500 syringe pump Results were recorded and analyzed

(such as spectra smoothing and in-line isotope pattern simulation) by software MassLynx

V35

NMR spectra were taken from Audepp solutions which was first evaluated by

Uv-Vis and ESI-MS to assure the characteristic optical absorptions and the mass signal

Then the solutions were dried in vacuuo resulting in some dark precipitates on the wall

of the glass vials Such dark particles were taken to be dissolved into CDCl3 and loaded

on the high-resolution liquid-state NMR spectrometers (Bruker Advance 360 at 14578

MHz for 31P-NMR and 36013 MHz for 1H-NMR respectively) Chemical shifts were

reported in ppm downfield with respect to Tetramethylsilane (TMS) and the external

reference of 85 H3PO4

TEM samples (evaluated first by Uv-Vis and ESI-MS to assure the characteristic

optical absorptions and the mass signal67) were prepared by drop-casting method onto

lacey carbon-coated copper grids (300 mesh by Ted Pella Inc) They were allowed to

111 dry in air for 4 to 24 hours TEM (regular resolution) was taken on Philips EM-420T

operating at an accelerating voltage of 120kV with tungsten source and images were

recorded on the CCD camera and analyzed by using calibrated Amt (V542) software

HR-TEM measurements were taken on and on JEOL EM-2010 LaB668 and JEOL EM-

2010F with field-emission source69 (both at 200kV accelerating voltage) respectively and

the images were recorded by Gatan TV rate camera and the associated software The

energy dispersive spectra (EDS) were run with a Gresham Sirius 30 Si (Li) X-ray

detector the take-off angle was set at 40deg

433 Calculation

In order to compare with results reported previously60 the density functional

theory (DFT) calculation was carried out (through collaboration22) within two different

approximations the B3LYP hybrid functional and PBE generalized gradient functional

Two basis sets LANL2DZ and SDD were used both with 60 electron core

pseudopotentials for Au and cores of different sizes for P Negligible differences were

seen in using different basis sets and functionals All calculations were performed using

the Gaussian03 program suite with default criteria for convergence and density grids In

some cases XQC was needed to converge the single-point energies The preliminary

results are used in facilitating the explanation of experimental observations no dedicated

discussion is given

112 44 Results

For the particular subject being studied here ESI-MS and Uv-Vis are very

sensitive at the atomic level therefore they were the two primary characterization

methods while 31P-NMR served as auxiliary tool TEM provided serendipitous

observation of SAA reported in the last section Both Results and Discussion parts are

organized this way accordingly

441 ESI-MS and Uv-Vis Spectra on Fresh Products

With good reproducibility ESI-MS spectra on fresh Audepp solution exhibit one

predominant peak at 3421-3423 mz in the high mass range (2000 to 4000 mz) and

shown in Figure 4-2 a It is assigned as [Au11(depp)3(PPh3)2Cl2]+ based on careful

examination of its isotope pattern (inset) Very occasionally without dedicated

quantitative control over the stirring speed andor stirring consistency clusters with Au11

core covered only (no PPh3) by depp and Cl [Au11(depp)4Cl2]+ could be observed as the

most intense cluster peak67 Slightly increased molar ratio of deppAuClPPh3 = 121 in

the starting materials could lead to the higher population of [Au11(depp)4Cl2]+ over

[Au11(depp)3(PPh3)2Cl2]+67 However such changes always gave rise to much impeded

reaction rate No effort in optimizing the formation of [Au11(depp)4Cl2]+ was pursued as

the initial interest involved preparing a sample with sufficient ion signal for ESI-MS

interrogation Nevertheless the [Au11(depp)3(PPh3)2Cl2]+ seems to be a precursor to

[Au11(depp)4Cl2]+ which is formed when the two PPh3 ligands are replaced by depp The

113 observation of this species reflects on the mechanism energetics and kinetics67 of the

overall cluster formation reactions especially reflecting the importance of ligand

exchange events A simplified possible formation pathway through clusters aggregation

and substitution 70 is proposed in Equation 1 (Figure 4-2 b)

b) Equation 4-1

Figure 4-2 (a) The representative ESI-MS of the fresh Audepp solution with the predominant peak of [Au11depp3(PPh3)2Cl2]+ (3421 mz) and (b) Equation 4-1 chemical reactions for the formations of [Au11depp4Cl2]+ (3117 mz) and [Au11depp3(PPh3)2Cl2]+

(3421 mz)

Moreover the Uv-Vis absorption characteristics (Figure 4-3 a) do not change

upon ligand exchange as being summarized by Mingos70 and the similar observations

obtained by Jin71 The two molecular clusters absorptions at 420 nm and ~ 300 nm72

114 which are characteristic of undecagold stabilized by phosphine ligands24 35 70 73 The

strong absorption at 420nm is attributed to the 5d to 6s interband transition of the gold

core74 and served as a benchmark in the present studies Also shown is another peak at ~

515 nm which is presumably due to a surface plasmon resonance (SPR) band from larger

(gt2nm52 75) gold nanoparticles and will be correlated with the TEM observations later

For comparison the optical properties (measured concomitantly with those for Audepp

solution) of the precursor AuClPPh3 is included in Figure 4-3 as well to show the

absence of the absorption from 280 nm upto the visible range The organic ligand ie

depp and the reducing agent TBAB are not supposed to give Uv-Vis absorption due the

lack of highly conjugated structures76

Figure 4-3 The Uv-Vis of a) the fresh Audepp solution (inset un-zoomed whole spectra) and b) the precursor AuClPPh3 (both are taken in 11 MeOhCHCl3 solvent)

115 442 ESI-MS and Uv-Vis Spectra on Aged Products

During the course of documenting the shelf-life of the as-prepared Audepp

solutions a red-shift in Uv-Vis absorption measurement was observed One example is

given in Figure 4-4 along with that already seen in Figure 4-3a as a comparison The

new molecular cluster absorptions are at ~337 nm and 430 nm They suggest the

conversion of undecagold clusters to the new formation of tridecagold clusters53 70 Also

shown is the 540 nm (red-shifted from 515 nm as in Figure 4-3a ) absorption attributed

to be the SPR representing for larger particles75 presumably due to the Ostwald ripening

over the longer setting period77 The optical properties of the precursor AuClPPh3 do

not exhibit any changes during the same period of time

Figure 4-4 Comparison of the Uv-Vis of the aged Audepp (in orange solid line) with the fresh Audepp (already seen in Figure 4-3 now in red and dashed line) Both are taken in 11 MeOhCHCl3 solvent

Re-checking on the aged product solutions via ESI-MS revealed more surprising

details for such spontaneous-growth behaviors shown in Figure 4-5 as the time goes by

the relative ratio of [Au11(depp)4Cl2]+ to [Au12(depp)4Cl3]+ to [Au13(depp)4Cl4]+ gradually

116 switched toward the higher mz range from a tri-modal (Figure 4-5 a22) through a

bimodal (Figure 4-5 b) to a monomial (Figure 4-5 c) distribution if only focusing on the

[Au11-13(depp)4Cl2-4]+ series These three major MPCs species are all electronically stable

with 8e configurations70 and each bearing 10 11 and 12 surface sties in consistent with

the spherical structural modes46 Also seen in Figure 4-5 a) and b) (the zoomed-in views

are in Figure 4-6 later along with other metastable species shown) is that each major

cluster mass signal is followed by 4 peaks with 16 amu separation evenly being

attributed to the oxidation on the four depp ligands The detection of phosphine oxide

ligands in ESI-MS is quite common58 and have been repeatedly reported60 58 78 79

Shown in Figure 4-5 c) only [Au13(depp)4Cl4]+ along with its ligand substitution

derivations (with the same tridecagold core) survived after months of setting These

derivatives show 131 amu separations evenly which could be attributed to ligands

substitution either by PPh370 or by monodentate depp58 following the partial ligand loss

induced by oxidation of depp66 Similar oxidation induced dissociation78 and the neutral

portion ligand loss induced by collision experiments in Audppp 35 were both reported

before Moreover such mass degeneracy was settled by supporting 1H-NMR which

shows the coexistence of aryl-protons and alkyl-protons67 to favor PPh3 substitution

events generating [Au13(depp)3(P1)(PPh3)Cl4]+ [Au13(depp)2(P1)2(PPh3)2Cl4]+ and

[Au13(depp)(PPh3)3(PPh3)3Cl4]+ in the range of 3714 to 3914 mz (the total number of

such substitutions is hard to predict in the range beyond 4000 mz) Except for

[Au13(depp)4Cl4]+ exhibiting oxygen addition peaks for four times other derivatives only

117 have one oxygen addition peak67 This difference suggests that Au13 bearing the

ldquoultimaterdquo (within the mass detection scope) stabilities comparing with Au11 and Au12

Figure 4-5 P(diluted in Merelative ratio oswitches towar

h

a) 15 mont

eriodic measurements on Audepp solutions as-prepared by ESI-MS OH ~ 15) reveals an interesting spontaneous growth behavior The f [Au11(depp)4Cl2]+ to [Au12(depp)4Cl3]+ to [Au13(depp)4Cl4]+ gradually

d the higher mz range

118 The power of this stability-based driving force is more manifested by the

disappearance of the series of metastable species recognizable in Figure 4-5 (with much

less intensities comparing with those of the major peaks of [Au11-13(depp)4Cl2-4]+) and

enlarged in Figure 6 with more details The less predominant stoichiometries are

presumably less stable because of either the 6e7e electron configurations andor lower

geometrical symmetries as summarized in Table 4-1 (multiple oxygen-adduction species

are omitted to preserve the clarity67) By simple countings one can tell that the total

number of the ligands is not fully or ideally covering the 12 surface sites of Ih cage

except for those major [Au11-13(depp)4Cl2-4]+ peaks in bold The important indication is

that they were ldquoscavengedrdquo along the time further confirming the remarkable stabilities

of trideagold

All the above reported mass assignments were confirmed by the corresponding

isotope pattern simulations Proposed formulations were evaluated on the agreements of

the centroid mass value the characteristic Cln pattern (specifically n = 2 to 6) as well as

the charge status (one-mass separation for singlet as (m+1) half-mass separation for

doublet as (m+2) 033 amu separation for triplet and so on so forth) with simulations

For clarity these detailed comparisons are available in somewhere else67

119

Figure 4-6 Close examination at the pFigure 4-5 reveals more dodeca- anprofoundly they were found to be ldquotridecagold

Au11 series

eds

Au13 series

Au12 series

aks beyond the depp-oxidation adduction in tridecagold-based cluster series More cavengedrdquo during the conversion toward

120

Clusters+ Mass (mz)

Oxygen Adduction

Electronic configure

Surface sitesligands

Au11(depp)4Cl2 3117 4 8e 1010 Au12(depp)4Cl3 3351 4 8e 1111

Au11(depp)3(PPh3)2Cl2 3421 4 6e 1212 Au13(depp)4Cl4 3583 4 8e 1212 Au12(depp)4Cl5 3419 4 6e 1113 Au13(depp)4Cl6 3653 4 6e 1214

Au12(depp)5Cl3(P1)O4 3722 5 8e 1212 Au13(depp)4Cl4(P1)2O5 3841 4 8e 1214 Au13(depp)4Cl5(P1)3O2 3917 4 7e 1216 Au13(depp)5Cl4(P1)O6 3986 beyond limit 8e 1215

Au13(depp)3Cl4(PPh3)(P1) 3712 1 8e 1212 Au13(depp)2Cl4(PPh3)2(P1)2 3843 1 8e 1212

Au13(depp)Cl4(PPh3)3(P1)3 3974 1 8e 1212

Table 4-1 Mass assignments for all peaks (major peaks are in bold) in Figure 4-5 to 4-6 showing their close association with tridecagold Species with ldquordquoare ambiguous in the electron status andor surfacevolume ratio due to the complication caused by O which could be associated with phosphorus or bound to Au They are assumed to be associated with lower symmetry structures

121

Figure 4-7 Mass assignments for a) [Au11(depp)4Cl2]+

(3551 mz) [Au (depp) Cl ]13 4 4+ (3583 mz) b) [Au1

[Au (depp-O) Cl ]13 4 4+ (3599 mz) were confirmed by th

MassLynx 3 080

Figure 4-5b

Figure 4-5c

(3117mz) [Au12(depp)4Cl3]+

(depp) Cl ]3 4 4+ (3583 mz) and

e isotope pattern simulated by

122 Conversions reactions70 from [Au11(depp)4Cl2]+ to [Au12(depp)4Cl3]+ and to

[Au13(depp)4Cl4]+ are proposed as following equations

Figure 4-8 Proposed chemical equations 2 and 3 for cluster aggregation in presence of precursor from Au11 to Au12 and Au13

443 31P-NMR

As ESI-MS results reveal rich information regarding the various core-ligands

distributions it does not indicate direct structural 58 andor binding information between

ligands and core Such desired information was preliminarily obtained through 31P-NMR

measurements shown in Figure 4-9 below as well as those for pristine depp and

precursor AuClPPh3 for comparison No definitive resonance assignment of the 31P-

NMR from the fresh Audepp solution (the same sample as for Figure 2 and 3) can be

made hence it is not shown here67

123

Figure 4-9 31P-NMR spectra of a) pristine depp (unbound free ligand) b) precursor AuClPPh3 c) aged (95months) Audepp measured in CDCl3

292 ppm (major) 407 ppm (minor)

As shown above these 31P-NMR results are pristine depp has one strong

resonance at - 236ppm consistent with its symmetrical structure which equalizes the

chemical environment of the two P atoms AuClPh3 has one resonance at + 332ppm

The aged AuDepp products ( [Au13(depp)4Cl4]+ predominant same sample as for Figure

124 4-5c ) has one strong resonance at +292 ppm and a minor at +407 ppm ( ~41 in area

ratio)

First special attention is paid to the substantially large (~ 50 ppm from the

negative range to the positive ppm) down-field chemical shift of P in depp and in the

Audepp clusters indicating a much decreased electron shielding environments Such

result suggests a large electron density being withdrawn from P toward Au core upon

coordination As the depp ligand with four ethyl groups on both ends is not considered

to be a significant π donor40 such effect is attributed to σ-donation of P electron40 to the

gold core and this electron donating interaction should have a comparable but different

strength to that in the precursor AuClPPh3 ( with 31P resonance at + 332 ppm ) This

topic will be revisited in the Discussion section later

Secondly the cleanness of the 31P-NMR for [Au13(depp)4Cl4]+ with small

portions of [Au13(depp)3-1(P1)1-3(PPh3)1-3Cl2]+ concomitants (refer to the Figure 4-5c)

enables the preliminary assignment of +292 ppm resonance to be from the P in depp

coordinating with Aun clusters47 81-83 Specifically this resonance is correlated well with

the 31P-NMR from single crystals [PdAu12(dppe)(PPh3)6Cl4]+ showing 2874ppm for

dppe47 The minor peak at +407 ppm78 could be from PPh3 in [Au13(depp)3-1(P1)1-

3(PPh3)1-3Cl2]+ The spectroscopic simplicity possibly arises from the high structural

symmetry of Au13 which is largely believed to be icosahedron (Ih)42 43 47 52-54 Notice

that there is no third resonance attributable to the P in P1 This might be related to the

similarities both chemically and structurally of the P in both depp and P1 which may

make them NMR-equivalent70 The relative ratio between them is largely in agreement

125 with what could be estimated from the mass distribution Depp [(2(4+3+2+1)] +

[P1(1+2+3) ] [PPh3(1+2+3)] = 43 1

No 31P-NMR of ldquoAudeppClrdquo or other possible concomitant smaller clusters are

found available in literature and thus their presence would not be definitively excluded

However the smaller Au-depp complexes such as ldquoAudeppClrdquo containing Au(I) in

higher oxidation state than in [Au13(depp)4Cl4]+ are supposed to result in stronger

electron de-shielding effects on P of depp upon coordination and thus much more low-

field chemical shift is anticipated for them In Mingosrsquo summary70 such trend is

recognizable as well with ~60ppm and 51ppm for P in [Au6(dppp)4]2+ to 368ppm for

[Au13(PMe2Ph)10Cl2]3 Due to the lack of the evidence for phase-purity of

[Au13(depp)4Cl4]+ the reported NMR spectra are still preliminary and more definitive

assignment will be given through more future investigation

444 TEM

Based on the observation of the ~515 nm SPR in Figure 4-3b) it is anticipated

that conventional TEM could capture at least partially images of particles with diameter

ge2nm75 and gain some size dispersity information of the as-prepared Audepp solution

Although the production of [Au11depp4Cl3]+ has been elusive and only

[Au11(depp)3(PPh3)2Cl3]+ was obtained more consistently previous reports52 53 74 proved

that features inferred from TEM examination are largely conserved within the same core

126 nuclearity even with a relatively flexible ligand constitution Therefore TEM analysis

was taken on the freshly prepared Audepp solution (evaluated first by ESI-MS and Uv-

Vis67) to gain information regarding the particle size distribution and morphologies as

shown in Figure 4-10

The TEM images of the diluted Audepp solution (Figure 4-10 a to b) clearly

depict their spherical morphologies as well as their narrow-dispersity in size Each

histogram in Figure 4-10 e) and f) summarizes manual and computer-aided analyses of

the particle diameters averaged at 31 nm for diluted samples and 43 nm for the

concentrated ones despite that only small population (represented by the first small

histogram in Figure 4-10 e) of the particles are imaged with sub-nanometer in size Such

results are consistent with the corresponding Uv-Vis in Figure 4-3 b) where the SPR

predicts the coexistence of molecular clusters and large particles Microanalysis on the

elemental information shows the presence of Au as well as P and Cl with the

characteristic energy bands of P (Kα band at 201 keV as a shoulder peak of Au Mα

band) Cl (Kα band at 262 keV) and Au (Mα1 band at 2123 keV Mα2 band at 2118 and

Mβ at 2204 keV)84 further confirming the chemical composition inferred from ESI-MS

The irregular shapes of the particles in Figure 4-10 c) are further examined by

HR-TEM and the bright-field images suggest particle overlaying with particle 1 and 3

are representing 2 ~3 Au-MPC units being together

127

Figure 4-10 Bright-field TEM images a) to d) for AuDepp solution with different concentrations all exhibit narrow size distributions as shown with the histograms in e) and f) EDS g) elemental information provides further evidence for the core-ligand composition inferred from ESI-MS (Philips EM-420T)

Spacing purpose

128

Figure 4-11 HR-TEM (bright-field images) on particles in Figure 4-10 c) from fresh Audepp solution without dilution (JEOL EM-2010 LaB6)

Moreover through closer inspection on the deposit from the concentrated solution

(Figure 4-10 d) a pattern of self-assembled-array (SAA63) was found

Figure 4-12 Bright-filed TEM images of the zoomed view of Figure 4-10 d) from fresh and concentrated Audepp products solution (scale bar 40 nm taken on Philips EM-420T)

129 The author then focused on the HR-TEM examination on such surface the results

are shown below

Figure 4-13 a) HR-TEM images of the as-prepared Au-MPCs b) the global FFT and c) the selected-area FFT both reveal lt111gt as the preferred orientations of the metaalic Au on such 2-D structures (JEOL EM-2010F at 200kV)

130 The lattice fringes show only one recognizable separation at 23Ǻ in close

agreement with the d-spacing of the lt111gt planes of bulk Au (selected d-spacings with

the relative intensity gt6 are listed in Table 4-285) Global FFT over the whole imaged

area reveals only one periodicity as one ring pattern with 42 nm-1 in diameter in the

reciprocal space which could be converted to the value in real space to be 238 Aring It is in

good agreement again with 2354 Aring of lt111gt planes of the bulk Au Another weak

outer ring could be recognized but ambiguously with 49 nm-1 in diameter in the

reciprocal space and the converted real space value to be 204 Aring It could be from the

lt200gt planes in bulk Au85 These two crystalline planes are the two type of surface in

icosahedral packing modes64 The preferred lt111gt orientation is more frequently (not

the most frequently64) observed than the orientation of lt200gt showing 4-fold symmetry

Therefore the predominant appearance of lt111gt planes is not surprising and forms the

strong basis for a classification of the observed structure to be a new type of Self-

Assembled Array (SAA)63

hkl d (Aring) Intensity (Relative) 111 23540 999 200 20386 460 220 14415 239 311 12294 242 222 1177 67

Table 4-2 Crystallographic data85 of bulk Au with FCC symmetry

131 The other two or four FFT spots could be recognized again very weakly at the

distance (69 nm-1 in the reciprocal space) largely corresponding to the lt220gt planes

(144 Ǻ)85 of bulk Au This indicates some minor inhomogeneity in the particle

orientation Notice the obvious fluctuation in the coverage thickness shown as darker

areas vs lighter ones as well as portions of uncovered areas It will wait to be seen if

the homogeneity of such 2D structures could be improved through future studies

45 Discussion

Much has been seen as [Au11(depp)3(PPh3)2Cl2]+[Au11(depp)4Cl2]+

[Au12(depp)4Cl3]+ and [Au13(depp)4Cl4]+ and together they exhibit a very close

association with one another Actually each of them conveys very important

fundamental chemistry points which will be addressed individually However such

individuality vanished as small clusters aggregate in the condensed phase on TEM grids

as addressed thereafter

451 Au11-MPCmdash a Model Cluster for Comparison Studies

As early as in 1976 Mingos86 reported detailed calculations on the

Molecular-orbitals (MO) of small gold cluster compounds and generalized a 8e model

symbolized as [Sσ]2[Pσ]6 to account for the most stable electronic structures and the less

132 stable [Sσ]2[Pσ]2-4 electron configurations This model has been successfully applied to

numerous cases including the production of [Au11(dppp)5]3+ with monodispersity

reported by Bertino et al recently35 However as Figure 4-5 shows the

[Au11(depp)3(PPh3)2Cl2]+ or [Au11(depp)4Cl2]+ appears prominently in the high mass

range In analogy to [Au11(dppp)5]3+ [Au11(depp)5]3+ would be expected to appear at

1089 mz however no such peak was observed The different stoichiometrical

preference ie with or without the Cl lies in the different electron donating π-accepting

properties of the different diphosphine ligands and is considered here

All phosphine (PR3) ligands in organometallic chemistry are both σ donors and π

acceptors and the relative strengths of these interactions is determined by the

electronegativity of the R groups40 A more electronegative R as in dppp withdraws

electrons from the P so that the P becomes more positive and better able to accept

electrons This is consistent with the π-acidity order40 increased from P-Alkyl3 to P-Aryl3

and with our preliminary DFT calculations22 which confirms that the P atoms of depp are

less positive than those of dppp with a natural population analysis giving respective

values of +083 e and +089 e Such difference is consistent with the preliminary 31P-

NMR (Figure 4-9) of [Au13(deep)4Cl4]+ that shows the large chemical shift ~50 ppm

upon coordination of depp with Aun clusters As a comparison ~30 ppm chemical shift

was observed79 from in a free dppp (δ= -182 ppm79) to in the PdCl2(dppp) complex (δ=

124 ppm79) The larger chemical shift in the former case indicating the less electron-

shielding76 around the P atoms in [Au13(deep)4Cl4]+ and therefore the larger degree of

electron donation from depp ligand to Aun (n= ~11-13) cluster cores

133 In light of this behavior the stoichiometry of the undecagold clusters is readily

understood For [Au11(dppp)5]3+ all ten exposed44 Au atoms are coordinated to P atoms

and the ligands pull electron density from the core enabling Au11 to adopt its preferred

3+ charge state (with an 8e core configuration) On the other hand [Au11(depp)4Cl2]+

which again is supposed to feature ten filled coordination sites shows that the tendency

of depp to push electrons onto the Au11 core leads to the necessity for two electron-

withdrawing Cl ligands to satisfy the preferred 3+ charge state Coordination of five

depp ligands to the Au11 core is prohibited either by the energetics of the formation

reaction or by a destabilization of the core The absence of [Au11(depp)5]3+ in the

experiments demonstrates clearly that depp is a poor approximation for dppp22

Control of the ligand-core interactions in a predictable way remains as an

interesting subject for organometallic chemistry to manipulate such factors to tailor

whatever properties as desired such as activity vs stability dispersity vs selectivity

etc40

452 Au13-MPC mdash the Destination as well as the Starting Point

The electronic stability and the idealized icosahedra symmetry of Au13-MPC have

been studied very intensively through both experimental42 43 47 52 53 87 and theoretical54

88 89 studies thus being well established

Such conclusion has special impact on the results reported herein Reviewing

Figure 4-5 and 4-6 one may ask ldquowhy and how did many other species disappear

through a spontaneous growth while only [Au13(depp)4Cl4]+ surviverdquo It is believed

134 that answers to such questions must stem from the ultimate stabilities of ldquoIh-Au13 (8e)rdquo

bearing both electronic and symmetrical stability It is such exceptional and

distinguished stability of [Au13(depp)4Cl4]+ that makes it as the only90 surviving species

sweeping off all other competitive species in the mass range being studied It surpasses

in abundance [Au11(depp)4Cl2]+ and [Au12(depp)4Cl3]+ which both have comparable

electronic stabilities by merit of higher structural stability It surpasses numerous

metastable species which are supposed to have yet idealized structural andor electronic

configurations by merit of both types of stability

A related conclusion was drawn recently by Tsukuda et al57 based on the

observation of the undisturbed stability of [Au25(SC6H13)18]x (x = 1- 0 and 1+) with

different electron count corresponding to the different core charge states and therefore

geometric rather than electronic factors are believed to be responsible for the magic

stability57 Reservation in accepting this argument was expressed by Murray et al6 It is

hoped that the reported spontaneous growth phenomenon via a series of electronically

stable clusters to reach the ldquoultimate destinationrdquo where electronic stability and

geometric stability meet serve as a good model where the electronic stabilities are met

first but then the geometric stabilities becomes supreme over the former stabilities to

balance these arguments

However its meaning is not just there yet Inspired by another report by the same

group of researchers24 where the structure of [Au25(PPh3)10(SR)5Cl2]2+ was resolved

crystallographically to be biicosahedral bridged by 5 sulfur atoms and sharing one Au in-

between the two icosahedrons of Au13 the author then turned to survey those reported

135 small gold MPCs with discrete core nuclearity and size smaller than 2 nm finding that

the Au13 is the starting point for larger cluster-assembled particles This trend annotated

by the number gold atoms in the cores is 670 870 970 1070 1144 70 13 42 52 53 70 and

then a leap-jump to 256 24 to 38913992 and to 5528 While the 55 cluster size represent

another ldquomagic numberrdquo64 65 in icosahedra-based packing and is revisited later 13 seems

to be the end of small cluster growing by monomer- or dimer- 46 based aggregation and

the starting point to initiate a building up pattern ldquoblock by blockrdquo( ~13x2 13x3) This is

strongly supported by the theorem of ldquocluster-assembled materials (CAM)rdquo93 that points

out the series of criteria (details can be found in the Chapter 1 in this thesis) for a cluster

species to serve as a building block for assembled materials Au13-MPCs as such

reported herein meet these requirements chemically electronically and structurally

A small discrepancy might be noticed by careful readers in that while most of the

reported Au13-55-MPCs are synthesized de novo6 meaning from the gold precursor

reducing agent and the protecting ligands some of them are prepared from

Au11(PPh3)8Cl3 being commercially available94 This seemingly indicates that the

building block is not necessarily to be Au13 However the spontaneous conversion from

Au11 to Au13 observed here may suggest that the Au13 formation during these

preparations is simply missed being insignificant by itself if one is only interested in the

final assembled product

136 453 Au12-MPC ndash- a Missed Entity in Mingosrsquo ldquoMaprdquo

As briefly mentioned earlier small gold MPCsrsquo aggregated has been

systematically studied and a map-like growth pathway was generaged46 where the growth

from Au9+ to Au13

5+ in particular either follows a ldquozigzagrdquo route (mono-based) between

the spherical (with [Sσ]2[Pσ]6 electron configuration) and the toroidal (with [Sσ]2[Pσ]4

electron configuration) pathways or a pair-wise addition of Au-dimmer along the

spherical pathway only While Au10 ends the toroidal pathway and Au11 grows into Au13

through the dimer-addition along the spherical route the Au12 was missed

Such paucity on Au12 is also found in searching the literature Only one study

based on DFT calculations on the lowest-energy structures provides direct structural

relevance88 In the series of endohedral gold clusters studied there M Au11 (analogy to

the homogenous cluster [Au12(depp)4Cl3]+ because the stoichiometry of the ligands is

1112 indicating 11 surface sites) was found to have two lowest-energy structures being

C5v or C2v in symmetry Interesting the HOMO-LUMO gaps linearly increase from

MAu10 (close to Au11) MAu11 (close to Au12) and MAu12 (close to Au13)

Assuming similar cage structures and the same trend in the LUMO-HUMO gaps for the

gold MPCs in particular the herein reported [Au11-13(depp)4Cl2-4]+ a surface potential

diagram is proposed in Figure 4-14 to account for the spontaneous conversion from

[Au11(depp)4Cl2]+ to [Au13(depp)4Cl4]+ via the intermediate species [Au12(depp)4Cl3]+

137

Figure 4-14 Proposed surface potential diagram for the auto-cluster-conversion the multiple ldquoblue linesrdquo represent a few metastable states (in Figure 4-5 and 4-6) close-lying to the [Au13depp4Cl4]+ the energy barrier from Au11 to Au12 to Au13 are supposed to be low Thus the profile of the surface potential is supposed to be very soft70

From there [Au12(depp)4Cl3]+ may be taken as a transition state species thus not

being able to be isolated in crystal forms Hence ESI-MS serves as a very unique

analytical tool to capture such transition state compounds Similar observations were

made on the detection of [Au12(DMSA)7]- concomitant with [Au11(DMSA)7]- and

[Au13(DMSA)8]- (DMSA = meso-23-dimercaptosuccinic acid) through laser-desorption

ionization (LDI)-MS25 27

138 454 Each Atom Matters

So far one may have seen that the dramatic difference could be brought about by

small changes in the cluster core size such as different surviving abilities and Uv-Vis

absorption characteristcs from [Au11(depp)4Cl2]+ to [Au13(depp)4Cl4]+ with the cluster

core size increasing by 2 gold atoms This represents a famous notation in cluster

science which is ldquoeach atom mattersrdquo21 93 95 Based on this knowledge an attempt to

clear up some recently addressed concerns24 on the Uv-Vis confusion on small gold

MPCs is made here

Refer to Figure 3 the altered optical properties from Au11 to Au13 are self-evident

This actually reveals a more profound message as discussed in the following Citations

on Uv-Vis spectra for Au1113 clusters have been unspecified explicitly Depending on

the specific properties being investigated some52 74 argue hat the electronic energy of

these sub-nanometer sized particles is very sensitive to surface protecting ligands

whereas others70 71 conclude that the electronic spectral characteristics are not sensitive to

changes in the ligands and are decided primarily by the nuclearity of the cluster Albeit

these discrepancies in practice for general confirmation on cluster size and dispersity

(both in narrow range) it has been largely acceptable to cite absorptions across different

ligands73 as well as different core sizes52 with similarities declared as assignment basis

However this practice sometimes result ambiguous assignments and concerns have been

raised24 67

By carefully inspecting a large number of published reports67 on Au11 and Au13

clusters it comes to the authorrsquos conclusion that it is not an active omission that has

139 confused this issue but it is 1 their resemblance (with subtle difference70) which is

very likely rooted from their similar electronic and geometrical structures70 and 2 the

dynamic conversion from Au11 to Au13 (or between them if it is reversible33) which

probably has been overlooked in most situations24 25 27 33 Thus the cross-citations are

practically acceptable but confusing

Only two reports are found to address such subtle differences one listed45 it as

ldquounpublished resultrdquo and another one33 gave no specification of the corresponding cluster

core size rather describing ldquooxidizedrdquo and the ldquoreducedrdquo forms Interestingly both of

them could find agreement in the system reported here For example the oxidation state

of Au11(depp)4Cl2]+ could be referred to as Au11(III) or Au+027 formally and as Au13(V)

or Au+038 for [Au13(depp)4Cl4]+ Thus the [Au13(depp)4Cl4]+ is the ldquooxidizedrdquo form while

Au11(depp)4Cl2]+ could be the ldquoreducedrdquo form Such clarification may introduce a simple

method to reverse the observed spontaneous growth by adding more reducing agent This

remains to be tested Moreover if such red-ox control can be conducted quantitatively

the transition species [Au13(depp)4Cl4]+ may be able to be isolated in the condensed

phase

In summary with the observations reported herein and detailed discussion such

type of confusions should be ameliorated

140 455 Aggregation and Self-Assembling of Small Au-MPCs Speculations

Isolated small ligand-protected gold clusters Au11-13-PMCs have been reported to

be sub nanometer in size at~08 nm52 96 However as indicated by Figure 4-3 in

addition to exist in forms of the small Au-MPCs the as-prepared Audepp products

solution also exhibits additional SPR band at 515 nm indicating the presence of larger (gt

2nm75) Au-MPCs aggregates which could be represented by the major populations in

Figure 4-10 a to b with the averaged particle diameter of 31 nm or just metallic Au

nanoparticles Since the EDS result does not provide any spatial distributions of the Au

P and Cl atoms no distinction can be made in-between them currently Moreover with

limited experimental data the inter-MPCsrsquo chemical bonding interactions that might be

one of the cuases responsible for such aggregation are unclear at present

However some hints could be found in literature for example one assembling

motifs was reported24 for the biicosahedral [Au25(PPh3)10(SR)5Cl2]2+ where the two Au13

icosahedra are linked by bridging ligands and sharing gold atom Another assembling

motif was found in a new synthetic procedure to obtain multinuclear aggregates from

[Cl2Pt(microS)2PtCl2] units97 the labile Clrsquos are replaced by (microS)2 through subsequent

evolutions one cycle after another and lead to the assembling of multinuclear aggregates

Hence a hypothesized ldquocross-linking polymerizationrdquo assembling mechanism is

speculated here the lability of the pseudohalide Cl ligands97 allows their replacement by

bridging depp ligands81 (gold atom sharing is also possible) meanwhile the multiple Cl

ligands on the Au-MPCs surface could facilitate such events to take place

simultaneously This might enable a crossing linking that finally stops at a certain points

141 kinetically or thermodynamically favored60 whereby the ligand substitution could be

effectively stopped to inhibit further core growth The possibilities of another type of

aggregation can not be excluded which is the reported ldquooxidative aggregationrdquo12 to be

responsible for the increased Au-MPCs particle size observed from TEM measurements

and confirmed by X-ray Photoelectron Spectrometry (XPS) Such procedure might take

place in current case during the preparations of the TEM specimen (see Experimental

section)

As for whether the Au11-based MPCs or the Au13-based MPCs are the building

blocks the latter ones are highly possible due to their higher stabilities and the auto-

conversion discussed before even this statement remains to be evaluated more67

Moreover the lower symmetry of Au11 D3v or D4d46 are not space-filling type64 98

Hence the discussion will proceed to the HR-TEM showing the SAA pattern on basis of

the symmetry of Au13 ie icosahedra

Noticed from the literature it is the fact that the formation of a ldquogiant clusterrdquo

[Pd561(phen)60](OAc)18099

( ~25 nm in diameter) was rationalized under the scheme of

ldquomagic numbersrdquo65 accounted for as being composed of 5 shells of icosahedral packing

The reported TEM image99 shares some similarity to Figure 4-12 except for not

possessing any regular arrangement between particles Recall that a trend of ldquoblock by

blockrdquo was proposed earlier for Au13-based cluster aggregation in the regime below 2

nm for larger nanoparticles especially for self-assembled arrays63(SSA) or self-

assembled monolayer (SAM)100 no clear correlation between the basic building blocks

and the final regular TEM pattern has been made77 A proposal is made here the ldquomagic

142 numbersrdquo trend (illustrated in Figure 4-15 below) might be one of the origins of the

formation of SAAsSAMs possibly from building blocks with uniformed size andor

shapes and grow ldquoshell by shellrdquo

Figure 4-15 Idealized nanoclusters of close-packed icosahedron with one to five shells of atoms together with the numbers of atoms (magic numbers) in these clusters(reproduced with permission from 65)

Specifically from icosahedral building blocks [Au13(depp)4Cl4]+ to a cluster-

assembled arrays with averaged diameter of ~43 nm (Figure 4-10 f) about 1100 to 1400

core atoms are needed based on the reported plot52 Based on the Equation 4 shown

below such a core size range corresponds to ~6 to 7 shells in the icosahedron packing

model64 (the total number of atoms in icosahedron model can be calculated to be 923 For

K=6 and 1415 for K=7) Thus the proposed ldquomagic numbersrdquo mode seemingly

rationalizes the particle size distribution and the SAA pattern

N= (103)K3 ndash 5 K2 + (113) K -1 (for icosahedrons as packing units) Figure 4-16 Equation 4 for he total number of atoms N in a Mackay icosahedron composed of K shells64 where K is referred to as the shell index in the given equation below K is defined to be 0 for the central atom

143 46 Future Work

This project was conducted for ~half a year with the instrumental interruption

occurring at an early stage Many conditions remained to be optimized such as the

selective formation of specific clusters Therefore this report should rather be an

ldquoanalyticalrdquo than a ldquosynthesisrdquo report Once the selective formation conditions are

optimized for material synthesis purposes more postsynthesis purification steps through

centrifugation gel electrophoresis27 57or HPLC should be included52 53

The SAA pattern is very interesting yet not optimized in terms of the controlled

gaps between particles and the layers of the arrays Future investigation along this

direction is very appealing to elucidate more quantitative details of this system starting

from more accurate knowledge of the condensed solution concentration to more HR-

TEM and Atomic Force Microcopy (AFM) along with quantified X-ray Photoelectron

Spectrometry (XPS) analysis

As the switch from Au11 to Au13 proceeds toward larger clusters it remains to be

tested if it can be reversed by adding more reducing agent33 more depp ligand or more

halide anions45

47 Conclusions

Experimental observations from the [Au11-13(depp)4Cl2-4]+cluster system

exhibiting both spontaneous growth behavior (in the cluster regime) as well as SAA

patterns (in the condensed phase regime) were obtained The former is rationalized by

144 the intrinsic stabilities of ldquoIh-Au13 (8e)rdquo while the latter could stem from the ldquomagic

numbersrdquo governed assembling ldquoshell by shellrdquo with estimated 7 shells to account for

the observed close-to SAM pattern Attempts at correlating the observations from these

two regimes were made for the first time to the authorrsquos knowledge ESI-MS is unique

in providing a window to observe the emergence of the embryonic clusters which are

believed to serve as building blocks to eventually form into narrowly distributed in size

as well as in shapes 2D structures on TEM grids

While the reported studies focus on the fundamental kinetics and

thermodynamics future potential applications are actually very broad imaging tags for

biological samples32 33 chiral optical agents73 CO oxidation catalysts89 as well as

magnetic data storage material77 Utilization of diphosphine ligands may represent a

promising method to isolate other clusters in the similar size regimes as Au13 such as

Al13-1 ref 101 and Met-Cars102 in future

48 Acknowledgements

The following people and their assistance are cordially appreciated by the author

Dr Bergeronrsquos (NIST) introduction of this project and continued helpful

discussions DrMagyarrsquos contribution (from the NIST Center for Theoretical and

Computational Nanoscience) with the preliminary calculation results Dr Clark and

DrWengrsquos valuable TEM experience and expertise on the HR-TEM data acquisition

145 The author gratefully acknowledges Dr Jin RC for his very inspiring

discussions during the manuscript preparation Mr Yang WR for all NMR acquisition

and valuable discussion on NMR assignment Dr Li R X for his patient help in

numerous scientific statistical analysis and figures plotting

Instrumental assistances are cordially acknowledged the reported Uv-Vis

measurements were taken in Dr Eklundrsquos group with MrLiursquos assistance in operating

the instrument and data fittings in Physics Department University Park all ESI-MS was

taken in the Mass Facility of the Huck Life Science Institute University Park all NMR

was taken in the NMR facility of Chemistry Department University Park and all TEM

was taken in the TEM facility of the Material Research Laboratory Innovation Park

Pennsylvania State University PA

The author greatly thanks the financial support from the US Department of the

Army (MURI NoW911NF-06-1-0280)

4-9 References

1 Wang Y Herron N Science 1996 273 (5275) 632-634

2 Kamat P V a M D Semiconductor Nanoclusters-Physical Chemical and

Catalytic Aspects Elsevier Science Amsterdam 1997 p 237

3 Sau T K Pal A Pal T Journal of Physical Chemistry B 2001 105 (38)

9266-9272

4 Dick K Dhanasekaran T Zhang Z Y Meisel D Journal of the American

Chemical Society 2002 124 (10) 2312-2317

146 5 Daniel M C Astruc D Chemical Reviews 2004 104 (1) 293-346

6 Tracy J B Crowe M C Parker J F Hampe O Fields-Zinna C A Dass

A Murray R W Journal of the American Chemical Society 2007 129 16209-16215

7 Ranganathan S Guo R Murray R W Langmuir 2007 23 (13) 7372-7377

8 Wang Y G Tang Y G Fu Y B Zhang L B Luo X Fang Y Shan W

W Du K Du A 2007

9 Wang Y G Zhang L B Luo X Tang Y G Fu Y B Qiangjiguang Yu

Lizishu 2006 (18(9)) 1515-1518

10 Yang X C Q J Z Wan Q L Mo ZH 2007 (19(5)) 689-694

11 Polizzi M A Stasko N A Schoenfisch M H Langmuir 2007 23 (9) 4938-

4943

12 Dasog M Scott R W J Langmuir 2007 23 (6) 3381-3387

13 Ruiz V Colina A Heras M A Lopez-Palacios J Electrochemistry

Communications 2007 9 (2) 255-261

14 Ibanez F J Zamborini F P Langmuir 2006 22 (23) 9789-9796

15 Griffin F Fitzmaurice D Langmuir 2007 23 (20) 10262-10271

16 Algar W R Krull U J Chemphyschem 2007 8 (4) 561-568

17 Wang M F Oh J K Dykstra T E Lou X D Scholes G D Winnik M

A Macromolecules 2006 39 (10) 3664-3672

18 Aharoni A Mokari T Popov I Banin U Journal of the American Chemical

Society 2006 128 (1) 257-264

19 Reiss P Bleuse J Pron A Nano Letters 2002 2 (7) 781-784

20 Gao L Lyn M E Bergeron D E Castleman A W International Journal of

Mass Spectrometry 2003 229 (1-2) 11-17

21 Castleman-group DURIP and MURI funding proposals University Park PA

2006

22 Golightly J S Gao L Castleman A W Jr Bergeron D E Hudgens J W


14627

147 23 Aslam M Mulla I S Vijayamohanan K Langmuir 2001 17 (24) 7487-

7493

24 Shichibu Y Negishi Y Tsukuda T Teranishi T Journal of the American


25 Negishi Y Tsukuda T Chemical Physics Letters 2004 383 (1-2) 161-165

26 Negishi Y Takasugi Y Sato S Yao H Kimura K Tsukuda T Journal of

the American Chemical Society 2004 126 (21) 6518-6519

27 Negishi Y Tsukuda T Journal of the American Chemical Society 2003 125

(14) 4046-4047

28 Balasubramanian R Guo R Mills A J Murray R W JACS 2005 127

8126

29 Wolfe R L Balasubramanian R Tracy J B Murray R W Langmuir 2007

23 (4) 2247-2254

30 De Souza A C Kamerling J P Analysis of carbohydrate-carbohydrate

interactions using gold glyconanoparticles and oligosaccharide self-assembling

monolayers In Functional Glycomics 2006 Vol 417 pp 221-243

31 Halkes K M de Souza A C Maljaars C E P Gerwig G J Kamerling J

P European Journal of Organic Chemistry 2005 (17) 3650-3659

32 Jahn W Zeitschrift Fur Naturforschung Section B-a Journal of Chemical

Sciences 2001 56 (8) 728-734

33 Jahn W Journal of Structural Biology 1999 127 (2) 106-112

34 Zhang H F Stender M Zhang R Wang C M Li J Wang L S Journal

of Physical Chemistry B 2004 108 (33) 12259-12263

35 Bertino M F Sun Z M Zhang R Wang L S Journal of Physical

Chemistry B 2006 110 (43) 21416-21418

36 Brust M Fink J Bethell D Schiffrin D J Kiely C Journal of the Chemical

Society-Chemical Communications 1995 (16) 1655-1656

37 Brown L O Hutchison J E Journal of the American Chemical Society 1999

121 (4) 882-883

148 38 Shelley E J Ryan D Johnson S R Couillard M Fitzmaurice D Nellist P

D Chen Y Palmer R E Preece J A Langmuir 2002 18 (5) 1791-1795

39 Tamura M Fujihara H Journal of the American Chemical Society 2003 125

(51) 15742-15743

40 Crabtree R H The Organometallic Chemistry of the Transition Metals 4th


41 Briant C E Hall K P Wheeler A C Mingos D M P Journal of the

Chemical Society-Chemical Communications 1984 (4) 248-250

42 Briant C E Theobald B R C White J W Bell L K Mingos D M P

Journal of the Chemical Society-Chemical Communications 1981 (5) 201-202

43 Vandervelden J W A Vollenbroek F A Bour J J Beurskens P T Smits

J M M Bosman W P Recueil Des Travaux Chimiques Des Pays-Bas-Journal of the

Royal Netherlands Chemical Society 1981 100 (4) 148-152

44 Smits J M M Bour J J Vollenbroek F A Beurskens P T Journal of

Crystallographic and Spectroscopic Research 1983 13 (5) 355-363

45 Mingos D M P Polyhedron 1984 3 (12) 1289-1297

46 Mingos D M P Journal of the Chemical Society-Dalton Transactions 1996

(5) 561-566

47 Laupp M Strahle J Angewandte Chemie-International Edition in English

1994 33 (2) 207-209

48 Zhu M Z Aikens C M Hollander F J Schatz G C Jin R C JACS 2008

ASAP

49 Smits J M M Beurskens P T Steggerda J J Journal of Crystallographic

and Spectroscopic Research 1983 13 (5) 381-384

50 Jadzinsky P D Calero G Ackerson C J Bushnell D A Kornberg R D

Science 2007 318 (5849) 430-433

51 Ingram R S Hostetler M J Murray R W Journal of the American Chemical

Society 1997 119 (39) 9175-9178

149 52 Menard L D Gao S P Xu H P Twesten R D Harper A S Song Y

Wang G L Douglas A D Yang J C Frenkel A I Nuzzo R G Murray R W

Journal of Physical Chemistry B 2006 110 (26) 12874-12883

53 Menard L D Xu H P Gao S P Twesten R D Harper A S Song Y

Wang G L Douglas A D Yang J C Frenkel A I Murray R W Nuzzo R G


54 Guliamov O Frenkel A I Menard L D Nuzzo R G Kronik L Journal of

the American Chemical Society 2007 129 (36) 10978-+

55 Fenn J B Mann M Meng C K Wong S F Whitehouse C M Science

1989 246 (4926) 64-71

56 Tracy J B Kalyuzhny G Crowe M C Balasubramanian R Choi J P

Murray R W Journal of the American Chemical Society 2007 129 (21) 6706-+

57 Negishi Y Chaki N K Shichibu Y Whetten R L Tsukuda T Journal of


58 Colton R Harrison K L Mah Y A Traeger J C Inorganica Chimica Acta

1995 231 (1-2) 65-71

59 Re-installation of Micromass Quattro II--a Triple Quandruple Tandem Mass

Spectrometer--in Castleman group instrument offered by DrJones In 2006

60 Bergeron D E Hudgens J W Journal of Physical Chemistry C 2007 111

(23) 8195-8201

61 Gao L Castleman A W Jr Bergeron D E Spontaneous-growth Behaviors

of Small Monolayer Protected Gold Clusters In 2008

62 Gao L Castleman A W Jr Dickey E Weng X J TEM Observation on

Bidentate Phosphone Ligands Protected Au-MPCs One of the Possible Origins of Self-

Assembling In University Park 2008

63 Wang Z L Journal of Physical Chemistry B 2000 104 (6) 1161

64 Martin T P Physics Reports 1996 273 199

65 Vargaftik M N Kozitsyna N Y Cherkashina N V Rudyi R I Kochubei

D I Novgorodov B N Moiseev II Kinetics and Catalysis 1998 39 (6) 740-757

150 66 Sigma-Aldrich-Technique-Support-Department Air and Moisture Sensitivity of

Depp In Gao L Ed University Park 2007

67 Gao L See supporting information in Appendix B In 2007

68 Clark T Gao L EELS Mapping on Jenny Lin Gaos Audepp sample prepared

on 090607-090707 In Material Chracaterization Laboratory Innovation Park Penn State

University PA 2007 Oct 16th

69 Weng X J Gao L HR-TEM measuredment on Jenny Lin Gaos sample

prepared on 090607-090707 In Material Chracaterization Laboratory Innovation Park

Penn State University PA 2007 October 11th

70 Hall K P Mingos D M P Progress in Inorganic Chemistry 1984 32 237-

325

71 Jin R C Similar observation on the optical properties of the single crystals

composed of the same Au25 cores with different ligands showing no sensitive change to

the ligand difference instead they are sensitive of the core structure In Gao L Ed

University Park 2008

72 Liu X M Absorption peak was fit with Igor Professional 601(Wave Merries

Inc Lake Oswego OR USA) Gaussian fit 29718+- 0158 (nm) Lorentzian fit

29714+- 0175 (nm) The peak broadening could be attributed to the large extent of

dilution of the sample soltuon More Uv-Vis spectra with better visulaized peaks can

be found in Appendix B (Figure B-2 and Figure B-3) In Gao L Ed University Park

2008

73 Yanagimoto Y Negishi Y Fujihara H Tsukuda T Journal of Physical

Chemistry B 2006 110 (24) 11611-11614

74 Yang Y Y Chen S W Nano Letters 2003 3 (1) 75-79

75 Njoki P N Lim I I S Mott D Park H Y Khan B Mishra S Sujakumar

R Luo J Zhong C J Journal of Physical Chemistry C 2007 111 (40) 14664-14669

76 Drago R S Physical Methods for Chemists (2nd) Scientific Publishers PO

Box 13413 Gainesville FL 32604 1992

151 77 Caruso F Colloids and Colloid Assemblies synthesis modifcation organization

and utilization of colloid particles Wiley-VCH Verlag GmbH amp Co KGaA Weinheim

2004

78 Nomiya K Yamamoto S Noguchi R Yokoyama H Kasuga N C

Ohyama K Kato C Journal of Inorganic Biochemistry 2003 95 (2-3) 208-220

79 Kanbara T Takase S Izumi K Kagaya S Hasegawa K Macromolecules

2000 33 (3) 657-659

80 Waters MassLyn 30 1998

81 Rackham O Nichols S J Leedman P J Berners-Price S J Filipovska A

Biochemical Pharmacology 2007 74 (7) 992-1002

82 Humphreys A S Filipovska A F Berners-Price S etal JChemSoc

Dalton Trans 2007 4943

83 Keim W Kraneburg P Dahmen G Deckers G Englert U Linn K

Spaniol T P Raabe G Kruger C Organometallics 1994 13 (8) 3085-3094



85 International-Center-for-Diffraction-Data 04-001-2616 Cubic Au


(13) 1163-1169


88 Gao Y Bulusu S Zeng X C Chemphyschem 2006 7 (11) 2275-2278

89 Graciani J Oviedo J Sanz J F Journal of Physical Chemistry B 2006 110

11600

90 Gao L Concomitant with some portions of ligand-substituted species with the

Au13-core as well as the saturated 12 sruface sites conserved thus the structural skeletal

(very pausible to be icosahedral) kept rigid the author will not intentionally spefify this

argument again in the following discussions In 2008

91 Donkers Murray Langmuir 2004

152 92 Schmid G Pfeil R Boese R Branderann F Merer S Calis G H M

vandenvelder J W A Chem Ber 1981 114 3634


94 Nanoprobe Inc Yaphank NY] In


999

96 Woehrle G H Warner M G Hutchison J E Journal of Physical Chemistry B

2002 106 (39) 9979-9981

97 Mas-Balleste R etal European Journal of Inorganic Chemistry 2004 3223

98 Qian Y T Crysallography in Chemistry (in Chinese) Department of

Publication USTC Hefei Anhui PRChina 1996

99 Vargaftik M N Zagorodnikov V P Stolyarov I P Moiseev II Likholobov

V A Kochubey D I Chuvilin A L Zaikovsky V I Zamaraev K I Timofeeva G

I Journal of the Chemical Society-Chemical Communications 1985 (14) 937-939

100 Whetten R L Khoury J T Alvarez M Murthy S Vezmar I Wang Z L

Stephens P W Cleveland C L Luedtke W D Landman U AdvMater 1996 8

428

101 Bergeron D E Castleman A W Morisato T Khanna S N Science 2004

304 (5667) 84-87

102 Guo B C Kerns K P Castleman A W Science 1992 255 (5050) 1411-

1413

153

Chapter 5

Conclusion Remarks

Nature favors symmetry from the snow flake to wild flowers Symmetry has

been the authorrsquos favorite as well From the dodecahedron of Met-Cars to the

octahedron of Zr6 to the icosahedron of Au13 as a few as just these three symmetries

the related chemistry and physics have manifested and pointed out to the endless beauty

in more extended unexplored fields The ever-increased diversity and the depth of the

understanding toward them are supposed to bring us a never-ending appreciation and

learning

Bare clusters are important on their own such as C60 however to a more

generalized extent ldquodecoratedrdquo clusters with organic (PR3 alkyl) or inorganic (O or C)

ligands on its surface brings more tunabilities in their properties thus enabling more

diverse functions and applications Throughout the studies reported in Chapter 2 to 4

much has been learned about the interactions between the cluster cores and such

ldquodecoratingrdquo ligand shells In conducting these series of studies being independent as

well as associated projects the author obtained the cherishable experience to potentially

rationally design cluster-assembled materials probably with particular interests on those

with connection from gas-phase studies to the condensed phase ones

Diffraction based X-ray crystallography and TEM along with ESI-MS have been

the indispensible methods in characterizing cluster-based materials reported in this thesis

154 Such technique combination is largely because the nature of the field being

interdisciplinary1 2 as well as crossing-phases3 Novel cluster-based structural units

could be identified by physicists from gas phase studies and gradually introduced into the

condensed phase andor onto surfaces later More than often the researchers in this field

have faced the elusive nature of both material quantity and quality The techniques

employed form a supplementary relation demonstrating their use to be a successful and

unique way to overcome these difficulties

Meanwhile new analytical strategiesmethodologies are expected to be developed

in keeping the pace of the rapid emerging of new cluster materials including

modifications on the existing technique (such as the surface deposition apparatus

modified from a TOF-MS) or expanding their ldquoroutinerdquo capacities (such as the metal

cluster identification from ESI-MS MALDI-MS) Such processes have proved to be

both challenging and fascinating

The history of cluster physics is now approaching ~30 years of active research4

Only during this limited time have we known that the properties of matter in the

intermediate range between atom and bulk can be altered dramatically ldquoatom by atomrdquo

It is believed that in the very near future cluster science will brings more and more

fascinating discoveries as well as profound modification on our perspective to the

physicschemistry of matter

155 References

1 Castleman A W Jena P Proceedings of the National Academy of

Sciences of the United States of America 2006 103 (28) 10552-10553



3 Jena P Castleman A W Proceedings of the National Academy of


4 Tarras-Wahlberg N Construction of an Apparatus for Production of Size-

selected Clusters Characterization of Magnetic and Optical Properties of Cluster Films

and Studies of the Photostability of Sunscreens Chalmers University of Technology

Gỏteborg University Sweden 2004

156

Appendix A

Zr-Met-Cars Deposition from Direct-Laser Vaporization (DLV) Source Technique Chemical and Crystallographic Difficulties

During 052002-052006 the author investigated the deposition of Met-Cars

(mostly on Zr-Met-Cars) from a Direct-Laser Vaporization (DLV) source on a home-

built Time-of-Flight Mass Spectrometry (TOF-MS) instrument

As considerable number of reports (ref Chapter 1) have been published regarding

the stabilityactivity of Zr-Met-Cars from gas-phase experiments and theoretical

calculations only a few theoretical predictions suggest the possibility to form these

species in the in condensed phase including an FCC close-packing arrangement

Harvesting sufficient amounts of Zr-Met-Cars from gas phase to surface-condensed phase

for ex-situ structural studies had been hampered by difficulties inherent in the chemical

and crystallographic nature of the cluster and the technique limitations as summarized in

this Appendix

A1 Technique Limitations

The reported deposition apparatus (see Chapter 2 and being referred to later as

ldquoNOVArdquo) was equipped with the DLV source which was designed to study arc-

discharge generated soot via mass spectrometry Such instrumentation was not necessary

to be a suitable one for high-throughput deposition purpose Although various efforts

157 have been made to modify it more toward deposition experiments the bottleneck

problem persists which is its low and non-consistency cluster beam fluence exhibiting as

random signal fluctuations between high intensity occasionally and low intensity mostly

Such difficulties had been encountered1 before A kinetic calculation2 points out the

maximum yields of Ti8C12 was 04 and 06 for Zr8C12 in arc plasma generator which

has very comparable conditions of DLV and in agreement with experiments3 4

Comparing with other cluster sources5-7 DLV for the formation of compound-clusters

without corresponding known bulk solids is rarely used for high throughput deposition

purpose

This problem generated a technique paradox if one wants to harvest the desired

cluster as much as possible the mass-gating window should be as broad as possible to

cover the whole width-of-based-line ~7 to 13 micros depending on the potential applied to

TOF plates For such time windows one can calculate8 (and the equation as the inset in

Figure A-1) energy dispersity is ~90 V-350 V which are also experimentally correspond

to the potential difference applied to the TOF plates On the other hand if one wants to

have the energy distribution as narrow as possible such mass-gating window must be

kept as narrow (according to the soft-landing conditions7 being le 1 eVatom and le 20 eV

for a 20-atom-cluster as in Met-Cars) to be ~ 1micros Not only this value goes beyond the

technique capability of the high-fast switches employed also it means that a substantial

percentage of the Met-Car signal has to be deflected off leading to poor deposition

efficiency A representative mass-gated spectrum is given below to represent the above

stated the paradox

158

Figure A-1 Mass-gating effect9 showing that only signals (baseline width of ~13micros) of Zr-Met-Cars are selected from the equation derived8 (inset) the energy dispersity of species in the ~13 micros time window is ~350V (S = ~260 m m =872 amu q =1 e)

Deposition experiments were conducted mostly following the former concern due

to the technique limitations of electronic components employed on the instrument

Therefore the TEM surface (deposition substrate see Chapter 2) was impacted by mass

selected Zr-Met-Cars with low kinetic energies of ~4eVatom to 17eVatom As shown

(below) from the mass spectra the majority of the deposits are composed of low mass

species being at least partially from the fragmentation upon landing A consistent

observation of the presence of low mass species including ZrC ZrO and Zr was

obtained from X-ray Photo Spectroscopy (XPS) measurement and will be shown later

159

Figure A-2 Second-Ion Mass Spectrometry (SIMS)10 of the Zr-Met-Cars deposit on TEM grid as prepared reveals much more low-mass species which is supposed to be at least partially from the defragmentation of Zr-Met-Cars upon landing on the surface

Other technique problems (shown in Table A-1 later) include the lack of the

implementation in-situ surface cleaning devices Along the time contaminants (likely

from a variety of different starting samples such as Si Co Cr Ag Ti V Nb in addition

to ZrC as well as possibility from the diffusion pump oil) builds up in the vacuum

chamber Maintenance of ultra-cleaning conditions is very crucial for surface- sensitive

techniques5 Unfortunately such surface contamination showed to be very interfering

during TEM imaging Examples are shown below

160

100nm

100nm

Figure A-3 Energy Dispersive Spectra (EDS) (left) and the corresponding bright-filed TEM images (right) of contaminant deposit The source of such contaminants is not clear

100nm

161

Moreover both theoretical11 12 and experimental13 results suggest that the surface

passivation is necessary to obtain isolated Met-Cars in a condensed phase Introduction

of any surface protecting ligands is not facilitated in the employed DLV source

configuration Suspicions of the deposit-surface interactions5 represents another issue

await for more investigation

It became evident that the employed instrument is not suitable for practically

effective and efficient material deposition purpose despite some preliminary success1

A2 Chemical Reactivities

As introduced in Chapter 1 Met-Cars have paradoxical nature as they exhibit

high stability in vacuum but very elusive though arguable air-stability (shown in next

page the presence of oxides is evident)

A brief re-enhancement merit of mentioning here is its potential polymerization

intendancy Quite a few independent calculations12 14 15 and one experimental report16

suggest the stronger stabilization of bounded Met-Car dimmers and possibly up to

tetramers than individual Met-Car units Possibilities of polymerization17 rather than

crystallization could be of the factors impeding the structural investigations via electron

diffractions in TEM detailed in the next section

162

Figure A-4 X-ray Photo Spectroscopy (XPS) measurement on as-deposited Zr-Met-car on TEM grids data deconvolution reveals 8 binding modes which can be classified into ZrO2 (495) ZrC (368) Zr(0) (45) There are other two peaks at 18096 eV (545) and 17855 eV (363) could be potentially assigned to be the binding modes in Zr(0) with 11 and -03 relative error respectively These results suggest the O2-sensitivity of Zr-Met-cars and the landing-energy induced decomposition of Met-cars into carbides

Zr 3d25

ZrO2 3d52

ZrO2 3d32

ZrC 3d 32

Zr() 3d52

Zr() 3d32

Zr() 3d32

Zrdeg 3d52

Zrdeg 3d52

Zrdeg 3d32

NameZrO2 3d52ZrO2 3d32ZrC 3d52ZrC 3d 32Zr() 3d52

Zrdeg 3d32

Pos1820918450180531829417855180961766717907

Area297441982422114147325452363427011799

Zr 3

d

x 102

6

8

10

12

14

16

18

20

22

24

26

CPS

188 186 184 182 180 178 176Binding Energy (eV)

A3 Crystallographic Challenges

Harvesting sufficient amounts of Met-Car species from gas phase into crystalline

forms has demonstrated to be very challenging Although TEM techniques has very low

requirement for sample quantity it does require very high quality of sample crystallinity

if one want to obtain structural information via electron diffractions Given the

163 heterogeneous nature of the deposited surface as mentioned above identifying any

crystalline phases on a deposited surface was very time consuming and research fund

costly

Available literature reference on the structures Met-Cars solids is very limited

Only three theoretical reports14 18 19 were found including one through private

communications These calculations suggest diamond-like crystals14 competitive

FCCSC(Simple Cubic)BCC (Body-centered Cubic)18 crystals in addition to be in FCC

lattice19 Therefore indexing diffraction patterns has to take the possibility of the

multiple crystal symmetries into consideration Unfortunately diffraction patterns

become less visually identifiable where other types of lattice are present instead of FCC

Definitive indexing requires very dedicated computing and simulating with specialized

softwarersquos with specialized expertise Such demanding probably can not be fulfilled

without much involvement of professional assistance Again due to the heterogeneous

nature of the deposited surface such analysis could turn out to be useless and thus be

very research resources consuming

In Summary the TEM investigations of Met-Cars deposits has not found repeatable

crystalline phase with large lattice constant indicating cluster-assemble solids More than

often only ZrC presumably arise from the energetic defragmentation as afore discussed

was found One example is given below

164

Figure A-5 Nanocrystals observed from the deposited species However the Selected-Area Diffraction Pattern (SADP as the inset) reveals the d-spacing of ZrC [220] planes (~235Aring) from lt100gt zone axis

20nm

A4 Summary and Prospective

By participating new funding proposals preparations20 the author along with other

team members summarized the limitation of the prototypical deposition apparatus

(NOVA) and proposed the corresponding corrections for the new instrumentation

(ldquoDURIPrdquo) designing (shown below)

165

Figure A-6 Schematic design of newly funded instrumentation

And the comparison table is provided

NOVA (problem)

ldquoDURIPrdquo (newly funded)

Improvement

DLV source (intensity inconsistency)

Magnetron Aggregation Source

Stability and reproducibility

Frequency (10 Hz) (Low) KHz Efficiency and

higher cluster flux

110-6 torr (HV) (High) 110-11 (UHV) Oil free surface cleanness

Removable substrate plate through feed through

(Large error of position control no temperature

control no gas)

Digitally-controlled cryostat stage with inert

gas matrix

Thermallized deposit at cold temperature and

kinetically ldquocushionedrdquo

No surface pre-treatment (Contaminant)

Ion gun for substrate cleaning

Purity of deposit contamination free

Ex-situ characterization (Oxidation)

In-situ spectroscopy + Load-lock chamber

Intact deposit chemicalstructural

property No

(Blind landing procedure)

Ion-current reading Deposit process under control and monitoring

Table A-1 Summary of technique limitations on employed instrument (NOVA) compared with recently funded new instrumentation (ldquoDURIPrdquo) which was designed accordingly to overcome these drawbacks

166

More experiments on it is supposed to bring more understanding about cluster-

assembled materials behaviors detected in-situ and landed on the ultra-clean surface with

more controlled deposition process Results wait to be seen

A5 Acknowledgements

The author grateful acknowledge Dr Lyn and Mr Groves for their very helpful

collaborations in pursuing the presented project DrBergeron and DrHydustky are

cordially acknowledged as well for their contributions in trouble shootings Financial

support was form AFOSR F is acknowledged

A6 References

1 Lyn M E Progress Towards Studying Metallocarbohedrenes in The

Condensed Phase Pennsylvania State University University Park 2002

2 Todorovic-Markovic B Markovic Z Nenadovic T Fullerene Science

and Technology 2000 8 (1-2) 27-38


Science 1993 260 (5105) 195-196

167 4 Selvan R Pradeep T Chemical Physics Letters 1999 309 (3-4) 149-

156

5 Yamada I Toyoda N Surface and Coating Technology 2007 201

8579-8587

6 Perez A Melinon P Dupuis V Jensen P Preve B Tuaillon J

Bardotti L Martet C Treilleux M Broyer M Pellarin M Vaille J L

Palpant B Lerme J JPhys D Appl Phys 1997 30 709-721

7 Gilb S Arenz M Heiz U MaterialsToday 2006 9 (7-8) 48

8 Knappenberger K L Jones C E Sobhy M A Castleman A W

Review of Scientific Instruments 2006 77 (12)

9 Grove D Gao L Data collection through collaboration with project

colleague In 2005

10 DrMarcus SIMS (soft conditions to avoid fragmentation) of ldquoZr8C12 on

lacey CCu gridrdquo on 073004 at Penn Sate Material Research Institute Mass

Spectrometry In 2004

11 Dance I Wenger E Harris H Chemistry-a European Journal 2002 8

(15) 3497-3511


13 Li S Wu H B Wang L S Journal of the American Chemical Society

1997 119 (32) 7417-7422

14 Zhao Y F Dillon A C Kim Y H Heben M J Zhang S B


168 15 Sobhy M A Castleman A W Sofo J O Journal of Chemical Physics

2005 123 (15)

16 Wei S Guo B C Purnell J Buzza S Castleman A W Science

1992 256 (5058) 818-820

17 Cooks R G Jo S C Green J Applied Surface Science 2004 231-2

13-21


19 Zhao J J Post Doctor In University of North Carolina and current

contact information zhaojjdluteducn 2002

20 Castleman-group DURIP and MURI funding proposals University Park

PA 2006

169

Appendix B

Supporting Information for Chapter 4

Most thermodynamic issues of Audepp experiments have been addressed in

details in Chapter 4 leaving the kinetics part partially to the future collision-induced-

dissociation (CID) studies through ESI-MSMS partially to some preliminary results

(Figure B1-B2) presented here

In Chapter 4 each sequential measurement was taken consistently on the same or

on product solutions showing reproducible EIS-MS and Uv-Vis characteristics These

confirming Uv-Vis and ESI-MS are shown here (Figure B3-B4)

To preserve the clarity detailed comprehensive analysis and zoomed-in views of

Figure 4-5 to 4-6 are supplemented here including the proposed reaction mechanism of

[Au13depp4Cl4]+ to form [Au13depp3-1(PPh3)1-3(P1)1-3Cl4]+ along with the supporting 1H-

NMR (Figure B5-B8)

Last a summary of the mass peak assignments and the optical absorption of

Au11-13-MPCs is tabulated

B1 Proposed two-step vs one-step reaction kinetics

Very occasionally without dedicated quantitative control over the stirring speed

andor stirring consistency clusters with Au11 core covered only (no PPh3) by depp and

170 Cl ie [Au11(depp)4Cl2]+ could be observed (Figure B-1 a the baseline was intentionally

raised to reduce the noise level due to the very low signal intensity) at 3117-3119 mz

And again the formulation assignment was confirmed by the agreement between

experimental and calculated isotope pattern (inset) Slight increase in the depp

concentration in the starting material could bring higher intensity of 3117mz over 3421

mz (in Figure B-1 b)

Figure Bmonodispermz over 34

-1 ESI-MS of fresh Audepp clusters a) Occasional observation of sed [Au11(depp)4Cl2]+ in the high mass range b) higher population of 3117 21 mz was achieved by having higher ratio of depp in the starting materials

171 Such difference is supposed to be kinetically determined and could be elucidated

by the scheme in Figure B-2 (green color indicates the favored process)

Figure B-2 Kinetic mechanisms with 11 ratio of depp gold precursor the production of [Au11depp3(PPh3)2Cl2]+ (3421 mz) is favored with 141 ratio the production of [Au11depp4Cl2]+ (3117 mz )is favored with ratio in between mixed effect is observed Along the time kinetic factors becomes leveled off by thermodynamic factors thus more depp-substituted [Au11depp4Cl2]+ is formed

Thermodynamically Aun clusters could be covered with depp-Cl only (no PPh3)

due to the increased entropy by merit of chelating effect 1of depp and in agreement with

other experimental observation2 It could possibly take place via a one-step (bottom

panels in Figure B-2) reaction However kinetically when the depp is insufficiently

excessive3 the formation of [Au11(depp)4Cl2]+ (3117 mz) may have to go through an

172 intermediate state mdash Au11 covered by mixed-ligands (top panels) as

[Au11(depp)3(PPh3)2Cl2]+ (3421 mz) with balanced entropy and kinetic factors

Consequently with any ratio in-between ratio formation of [Au11depp4Cl2]+ is favored

yet not optimized The proposed optimized ratio waits for future evaluation

B2 Supporting Uv-vis and ESI-MS for TEM results

Fresh Audepp used for Figure 4-10 to 13 was measured by Uv-Vis spectroscopy

first The original digital files were lost due to some technique malfunction

Figure B-3 The Uv-Vis absorption of Audepp clusters measured at a series of timing pointson a Hewlett-Packard 8453 diode-array spectrometer The spectra were recorded as ldquotiffrdquo file by the Agilent ChemStation software (inset an independently measured Uv-vis on fresh Audepp prepared in the same way as reported in Chapter 4 was collected on a dual beamVarian Cary 3C Uv-Vis spectrophotometer at NIST4)

173 The absorption of the precursor AuClPPh3 in the ultraviolet range could be seen

until after 14 hours indicating that the reaction rate is rather low presumably at the

ligand-substitution step

Corresponding ESI-MS is shown below Itrsquos worthy of pointing out that ESI-

MSESI-MS is very sensitive to instrumental conditions from run to run while the major

peaks are reserved by merit by their stabilities minor peaks have been observed but

inconsistently Assignments on such minor peaks have not be strictly performed

Figure B-4 Pre-TEM analysis (for Figure 4-9 and 4-11) on Audepp product solution via ESI-MS the population of [Au11depp4(Ph3)2Cl2]+ (3421 mz) is dominant other clusters including [Au11depp4(Ph3)2Cl2]+ (3117 mz) are observable No prediction can be made regarding the potential kinetics-controlled reactions during product solution condensation

174 B3 Supporting ESI-MS and 1H-NMR for Figure 4-5c

The formation of the ligand-substituted other cluster species is proposed in the

following equation

Figure B-5 Proposed mechanism for the formation of three ligand-substituted clusters induced by oxidation on depp

A zoom-in look with focus on the closer inspection of possible small peaks such

as the four-oxygen adduction or related new clusters However the cleanness is seen as

the Audepp solution evolutes into the stage where only tridecagold species are dominant

This is attributed to the electronic as well as geometric stabilities of tridecagold clusters

Figure B-6 Zoomed-in look at Figure 4-5c Other than one oxygen-adduction peaks other small peaks could be negligible in intensity the relative cleanness forms sharp contrast with what is shown in Figure 4-6

175

While the Au13 core was reserved it is possible to assign the series of derivative

clusters in two ways following either ldquoP8rdquo or ldquoP9rdquo patterns (named after the

distinguished formula used for the simulation) shown below

Oxidation induced

middotP2 + middotP1

ldquoP8rdquo= P2-elimination and PPh3-

[Au13(depp)3(P1)(

[Au13(depp)2(P1)2(P

[Au13(depp)(P1)3(P

ldquoP9rdquo = P1-elimination and depp-[Au13(depp)

3[Au13(depp)4

[Au13(depp)4

Figure B-7 Two possible oxidation-induced fragmentation on depp lead to two possible mass assignments to the Au13 derivatives being equivalent in mass and supported by the isotope distribution

Given the notice that as more depp bounds with gold cluster cores there leaves

more PPh3 than depp in the equilibrium solution ldquoP8rdquo is more kinetically favored

Moreover with more experimental tests the ldquoP8rdquo route was confirmed by 1H-NMR

(from the same Audepp product solution for Figure 4-5c) shown below which suggests

176 the presence of both phenyl protons (characteristically at ~74 ppm with three mutiplets

in area ratio of 3345) and alkyl protons (at the high-filed range from 07 ppm to 40

ppm with the 123 ppm peak being attributed to H2O in CDCl3) whereas only alkyl

protons should have been seen if ldquoP9rdquo route has had followed Normalized

phenyldepp(PP-P) ratio is ~13 being consistent with that of P-NMR on the same

sample However the completely individualized assignment to the low-filed resonances

can not be achieved at present due to oxides complicated chemical environments

Figure B-8 1H-NMR (in CDCl3) of 95 month Audepp showing distinguished high-field and low-filed resonances for alkyl protons and phenyl protons respectively

B4 Detailed analysis of all small peaks presented in Figure 4-5

Except for a few high mass peaks which become very small in intensity and un-

symmetric in peak shape all peaks presented in Figure 4-5 were examined carefully as

listed below

177 Electron

config Au PPh3 depp Cl P1 P2 O Mass M+2 Formulation ExpFigure 3117 1 O

2 O2

3 O3

4 O4

3351 1 O

2 O2

O3

1O4

1 1

11 4 2 3133 3135 Au11Cl2P8C44H104 radic Fig4-6 aplus 11 4 2 3149 3151 Au11Cl2P8C44H105 radic Fig4-6 a4 O 11 4 2 3165 3167 Au11Cl2P8C44H106 radic Fig4-6 a

peaks 11 4 2 3181 3183 Au11Cl2P8C44H106 Π Fig4-6 a

12 4 3 3365 3367 Au12Cl3P8C44H104 radic Fig4-6 bplus 12 4 3 3381 3383 Au12Cl3P8C44H105 radic Fig4-6 b4 O 12 4 3 3 3397 3399 Au12Cl3P8C44H106 Π Fig4-6 b

peaks 12 3 3 3391 3393 Au12Cl3P7C51H93 radic Fig4-6 b12 4 3 4 3413 3415 Au12Cl3P8C44H106 Π Fig4-6 b12 3 3 3407 3409 Au12Cl3P7C51H93O radic Fig4-6 b

Other 12 4 5 3419 3421 Au12Cl5P8C44H106 radic Fig4-6 bAu12 12 4 5 1 6O3435 3437 Au12Cl5P8C44H10 radic Fig4-6 bcores 12 4 5 3451 3453 Au12Cl5P8C44H10 radic Fig4-6 bplus 12 4 5 3467 3469 Au12Cl5P8C44H10 radic Fig4-6 b 4 O 12 4

2 6O2

3 6O35 4 O43483 3485 Au12Cl5P8C44H106 radic Fig4-6 b

13 4 4 3597 3599 Au13Cl4P8C44H104 radic Fig4-6 cplus 13 4 4 3613 3615 Au13Cl4P8C44H104 radic Fig4-6 c4 O 13 4 4 3629 3631 Au13Cl4P8C44H104 radic Fig4-6 c

peaks 13 4 4 3645 3647 Au13Cl4P8C44H104 radic Fig4-6 c

13 4 6 3651 3653 Au13Cl6P8C44H104 radic Fig4-6 cOther 13 4 6 3667 3669 Au13Cl6P8C44H10 radic Fig4-6 cAu13 13 4

3583 1 O

2 O2

3 O3

4 O4

1 4O

6 2 4O23683 3685 Au13Cl6P8C44H10 radic Fig4-6 cplus 13 4 6 3 4O33699 3701 Au13Cl6P8C44H10 radic Fig4-6 c4 O 13 4 6 4 4O4

4 O45 O5

6 O6

3715 3717 Au13Cl6P8C44H10 Π Fig4-6 cOther 12 5 3 1 3722 3724 Au12Cl3P11C59H140 Π Fig4-6 cAu12 12 5 3 1 3738 3740 Au12Cl3P11C59H140 Π Fig4-6 cplus 12 5 3 1 3754 3756 Au12Cl3P11C59H140 radic Fig4-6 c

5 12 5 3 1 3770 3772 Au12Cl3P11C59H1407 O7 radic Fig4-6 cO 12 5 3 1 3786 3788 Au12Cl3P11C59H1408 O8 radic Fig4-6 c

peaks 12 5 3 1 3802 3804 Au12Cl3P11C59H140 Π Fig4-6 cOther 13 4 4 2 3839 3841 Au13Cl4P10C52H124

9 O9

5 O5 radic Fig4-6 cAu13 13 4 4 2 3855 3857 Au13Cl4P10C52H124 Π Fig4-6 cplus 13 4 4 2 3871 3873 Au13Cl4P10C52H124 Π Fi

6 O6

7 O7 g4-6 c4 O 13 4 4 2 3887 3889 Au13Cl4P10C52H1248 O8 radic Fig4-6 c

Other 13 4 5 3 3915 3917 Au13Cl5P11C56H1342 O2 radic Fig4-6 cAu13 13 4 5 3 3931 3933 Au13Cl5P11C56H134 radic Fig4-6 cplus 13 4 5 3 3947 3949 Au13Cl5P11C56H134 Π Fig4-6 c4 O 13 4

3 O3

4 O45 3 3963 3965 Au13Cl5P11C56H134 Π Fig4-6 c

Au13 13 6 3 3986 3988 Au13Cl3P12C66H1565 O5

radic Fig4-6 c

Electron

config Au PPh3 depp Cl P1 P2 O Mass M+2 Formulation ExpFigure 13 1 3 4 1 3712 3714 Au13Cl4P8C55H103 radic Fig 4-6 d

4 13 1 3 4 1 1 3728 3730PPh3 13 2 2 4 2 3843 3845 Au13Cl4P8C66H102 radic Fig 4-6 dsub 13 2 2 4 2 1 3859 3861P1 13 3 1 4 3 3974 3976 Au13Cl4P8C77H101 radic Fig 4-6 d

elimi 13 3 1 4 3 1 3990 3992

3583plus O

plus O

plus O

Note Colour codes purple for hypothesized species redbold for the composition and mass of significant species as well as the number of oxygen adduction blue for distinguishable isotopes Experimental observations were compared with simulated isotope (see Appendix B) radic for matching and times for ambiguous observation due to too low signal intensity or peaks overlapping Table B-1 Mass assignments for all significant peaks (red and bold) and small oxidize peaks (recognizable in Figure 4-5 and detailed in Figure 7)

178 All mass assignments are based on comparing with the isotope pattern

simulations

c) Range 3435 mz to 3470 mz


179 Spacing Purpose

d) Range 3651 mz to 3721 mz

e) Range 3755 mz to 3787 mz

f) 3714 mz


180

g) Range 3841 mz to 3889 mz

h) Range of 3917 mz to 3933 mz

i) 3987 mz


181

B6 Summary of Uv-Vis on Au11 to Au13

Solutions of Au clusterscolloids6 are famously for their very distinguished color

arrays7 Larger gold particles (ge 2nm) display the well known surface plasmon resonance

(SPR) at about 520nm8 and beyond Solutions with gold particles less than 2 nm in

diameter and polydispersed leaving decreased or disappeared SPR while showing an

exponential increase from the visible to the ultraviolet region9 With further decrease in

size nanometer to sub-nanometer the emergence of discrete peaks as ldquomolecular

absorptionrdquo is observed9 10 This trend well represents the notation that clusters are the

transition from bulk materials to a regime described by discrete molecule-like

behaviors11

Citation on optical absorption of Aun (n = 11 to 13) clusters2 3 9 10 12-17 has been

ldquomessyrdquo A summary could help in recognizing certain unintentional neglecting for

readerrsquos interest as well

182

Clusters Reference Observed Absorption Maxima (nm)

Au11 (cage structure)

Au11P7Cl3 Yang and Chen 2002 Nano Letters 313-325 416

Au11P8Cl3 Woehrle and Hutchison 2002 JPCB 309 416

Au11P8Cl3[Au9-and Au10- coexist)]

Shichibu and Teranishi 2005 JACS 320 420

Au11P7Cl3 and Au11 (BINAP)4 Br3

Yanagimoto Tsukuda 2006 JPCB 305 430

[Au11(dppp)5]3+ Bertino Wang 2006 JPCB ~300 420 (L3)

[Au11(PMePh2)10]3+ Mingo 1984 Prog Inorg Chem 298 422


Au13P4S2Cl2 Menard Nuzzo and Murray 2006 JPCB 330 415

Au13P4S4 Menard Nuzzo and Murray 2006 JPCB 330 415-440

[Au13Br2(dppe)5]Br3 Mingo 1984 Prog Inorg Chem 334 420

[Au13Br4P8]Br Mingo 1984 Prog Inorg Chem 340 425

Au12 (crown-shape) Au12DMSA7

[(AuL)=(117)(138) coexist)]Negishi and Tsukuda 2004 CPL and 2003JACS 290-300 390

(not cage but in crystal form) Au12(P-P)6S4

Yam and Cheung 1999 Angew Chem 332

(not cage but in crystal form) Au12P2(P-P)6Cl2

Sevillano and Fenske 2006 ZAnorgAllgChem 355

Note Shoulder peaks are omitted for clarity DMSA meso-23-dimercaptosuccinic acid and TOA tetraoctylammonium cation P=PR3 S = thiol ligand P-P = bidentate phosphine ligand Table B-2 Summary of Uv-Vis absorption from all recent publications

183 B7 References

1 Crabtree R H The Organometallic Chemistry of the Transition Metals

4th Edition Wiley-Interscience 4 edition 2005 May 5


Chemistry B 2006 110 (43) 21416-21418

3 Woehrle G H Warner M G Hutchison J E Journal of Physical

Chemistry B 2002 106 (39) 9979-9981

4 Bergeron D E Communication Audepp at PSU In Gao L Ed


5 Drago R S Physical Methods for Chemists (2nd) Scientific Publishers

PO Box 13413 Gainesville FL 32604 1992

6 Brust M Kiely C recent literature indeed no longer distinguishes

clearly between clusters colloids and nanoparticles and all terms are used according

to the personal preferences of the authors Wiley-VCH Verlag GmbH amp co KGaA

Federal Republic of Germany 2003

7 Caruso F Colloids and Colloid Assemblies synthesis modifcation

organization and utilization of colloid particles Wiley-VCH Verlag GmbH amp Co

KGaA Weinheim 2004

8 Njoki P N Lim I I S Mott D Park H Y Khan B Mishra S

Sujakumar R Luo J Zhong C J Journal of Physical Chemistry C 2007 111 (40)

14664-14669

184 9 Menard L D Gao S P Xu H P Twesten R D Harper A S Song

Y Wang G L Douglas A D Yang J C Frenkel A I Nuzzo R G Murray R

W Journal of Physical Chemistry B 2006 110 (26) 12874-12883


11 Jena P Khanna S N Rao B K Surface Review and Letters 1996 3

(1) 993-999

12 Shichibu Y Negishi Y Tsukuda T Teranishi T Journal of the


13 Yanagimoto Y Negishi Y Fujihara H Tsukuda T Journal of


14 Hall K P Mingos D M P Progress in Inorganic Chemistry 1984 32

237-325

15 Negishi Y Tsukuda T Chemical Physics Letters 2004 383 (1-2) 161-

165

16 Yam V W W Cheng E C C Cheung K K Angewandte Chemie-

International Edition 1999 38 (1-2) 197-199

17 Sevillano P Fuhr O Matern E Fenske D Zeitschrift Fur

Anorganische Und Allgemeine Chemie 2006 632 (5) 735-738

185 Appendix C

Calibration Documents of Negative-MALDI1

Figure C-1 Negative-MALDI calibration was conducted 1 using Bio-Cal3 which is primary for high mass range calibration for proteomics studies The low mass calibration range is around 800 mz

Low M

ass Limit (m

z) 8041

1DrBruces and DrAnne Bruces Hershey Medical School Penn State University

Hershey PA

VITA

Lin Gao

Birth Apr24 1976 Xirsquoan PRChina

Academia

091994-061999 BS University of Science and Technology of China--institute of CAS Inorganic Chemistry Division Advisor Dr Chenl Honor First-degree Award of Bachelor Thesis

012000-082001 MS University of Illinois at Urbana-Champaign Bioinorganic Division Advisor Dr Lu Honor John-Bardeen Fellowship Nomination

092001-present Penn State University University Park Physical and Material Chemistry Advisor Dr Castleman PhD Committee Members Dr Dickey Dr Mallouk and Dr Sen Thesis Studies on Cluster-Assembled Materials from the Gas Phase to Condensed Phases

Families Husband Ruoxin Li PhD Physics Department Yale University 2007 Daughter Xiaoqing Alice Gao 12 year old DOB 12232006 State College PA Parents Yuxiang Gao (Father) and Qunying Dong (Mother) PRChina Sister Xin Gao PRChina

Abstract

Chapter 1Introduction


12 Motivation


14 References

Chapter 2Mass Deposition and Preliminary Structural Study o

21 Abstract

22 Introduction

23 Experimental

24 Results

25 Discussion

26 Conclusion

27 Acknowledgements

28 References

Chapter 3Application of Solvothermal Synthesis to Isolate

31 Abstract

32 Introduction

33 Experimental


Single Crystal Growth

Structures Determination

Mass Spectrometry Analysis

Other Techniques for All Immediate Analysis

34 Results




3431 By-products

3432 Significant Crystallographic Results


35 Discussion


352 Mass Spectra

353 Classification



356 Prospects



36 Conclusions

37 Acknowledgements

38 References

41 Abstract

42 Introduction

43 Experimental



433 Calculation

44 Results


442 ESI-MS and Uv-Vis Spectra on Aged Products

443 31P-NMR

444 TEM

45 Discussion


452 Au13-MPC mdash the Destination as well as the Starting Po

453 Au12-MPC ndash- a Missed Entity in Mingosrsquo ldquoMaprdquo

454 Each Atom Matters

455 Aggregation and Self-Assembling of Small Au-MPCs Spe

46 Future Work

47 Conclusions

48 Acknowledgements

4-9 References

Chapter 5

Conclusion Remarks

References

Appendix A

Zr-Met-Cars Deposition from Direct-Laser Vaporization (DLV)





A5 Acknowledgements

A6 References

Appendix B




B3 Supporting ESI-MS and 1H-NMR for Figure 4-5c

B4 Detailed analysis of all small peaks presented in Figure


B7 References

Appendix C


The thesis of Lin Gao was reviewed and approved by the following

A Welford Castleman Jr Evan Pugh Professor of Chemistry and Physics Eberly Distinguished Chair in Science Thesis Advisor Chair of Committee

Thomas Mallouk DuPont Professor of Materials Chemistry and Physics

Ayusman Sen Professor of Chemistry Head of the Department of Chemistry

Elizabeth Dickey Associated Professor of Material Science and Engineering Associate Director of Material Research Institute

Signatures are on file in the Graduate School

iii

Abstract






























































the SAAs



















Chapter 5 153


References155

Appendix A156



Appendix B 169



Appendix C185


ix List of Figures




m n+

4 12 5


8 1240 7


45

2 2 8


h

49 8



8 12

c60 10



20

23





27

d30



X )

696 12 6

m-

52 i

a 44




6 14 4101 53


6 12 6n-

4

56


6 12 6n-

4

58


micro i oxo

micro 64



6 12 62-

66


6 12 6-

67




6105 81


6 5 3 2 5 3 7108


11 3 3 2 2+

11 4 2+

11 3 3 2 2+ 113


3 3114



11 4 2+

12 4 3+

13 4 4+ 117




11 4 2+

12 4 3+

13 4 4+

13 4 4+

13 4 4+

80 121



31

3 3 123






13 4 4+

11 12

1370137



64

142



9

8

158


10

159



2

2

162












1

176





1

185

xv

List of Tables











457


4 59


4 60


4 61


4 62


4 63



























































my miracle

xix Dedicated To

My dear families

Mentors and friends

Chapter 1

Introduction






















(Figure 1-1)



















































12 Motivation




transition metals






























7











8












+
























motivations

11







therein








































14 References




Bowl 2007 Vol 59 p 64-64




Processes 1992 118 167-189




Physics 1981 74 (11) 6511-6512



1985 318 (6042) 162-163


999



1413


256 (5056) 515-516




2004 304 (5667) 84-87




New York 1994



20 Pauli W Science 1946 103 (2669) 213-215








(4) 569-572



122-128


Matter 2006 18 (41) 9509-9517




105-110


115 (15) 6958-6961


Science 1993 260 (5105) 195-196


Physics 1997 106 (6) 2231-2238


(51) 10486-10492




Engineering 2006 14 (4) 637-646


(6) 893-901


Compounds 2007 433 (1-2) 79-83


495-542




2005 123 (15)


2006 252 (19) 6463-6465


Physics Letters 2004 398 (4-6) 292-296


115 (10) 4395-4396


3497-3511


Review Letters 1999 83 (24) 4983-4986


Letters 2001 349 (3-4) 220-226



256 (5058) 818-820






Chemistry A 2006 110 (10) 3505-3513


Chemical 2005 239 (1-2) 116-124


2004 108 (49) 18796-18798


10903


Physics 2006 124 (16)



15 (25) 4341-4348


Physics Letters 2006 425 (4-6) 273-277









14627




18

Chapter 2



21 Abstract














diffraction








20

22 Introduction
















packing motifs
























22 23 Experimental














23

















24 Results

















1 relative errors

i hkl 3

Ri (mm) (Reciprocal



θri-r12 (Inter-

planar angle)

DiD1 (Spacing

Ratio)












27


(A)

(B)

+ [361]

(-313)

(-420)

(-11-3)

(3-1-3)

(4-20)

(1-13)








28

i hkl 2

Ri (mm) (Reciprocal



θri-r11 (Inter-

planar angle)

DiD1 (Spacing







25 Discussion



d cong λLr (1)





















30






confidence





present experiments



below)



467(11) 311 (11) frac12 1548(36) 348(6) 331 (19) frac12 1515(26) 344(6) 420 (20) frac12 1538(27)




Spacing



Radii Ratio


15













+4 068 080 12 0 149 160 11









atoms










26 Conclusion







assembly




























28 References




(16)



(5200) 999-1001


19211-19214


119 (32) 7417-7422



1413


Science 1993 260 (5105) 195-196


1957






(42) 7695-7698





256 (5058) 818-820


495-542







Society 1993 115 (16) 7415-7418






PA 2006








1954-1955

38

Chapter 3



31 Abstract













39 32 Introduction





































































In summary


Number of


Interaction Types

(Met-Cars-L)





complexation

111


























































46 33 Experimental





































































package99










































34 Results







reported101

53














File Name (Log pg)


Starting

material Note


supernatant

jlg2 (pg B42)


a ZrC soot clear


jlg5


90deg V=1203Aring3




3431 By-products








File Name (Log pg)

Lattice Constant


Note


(a b c)(αβ γ)(V)


591 Aring3



brown top

phase c

(a b c)(αβ


90deg 90deg 90deg

1373 Aring3


top phase c

(a b c)(αβ γ)(V)


916deg 520 Aring3













2[N(nBu)4]







[ ] ( )

( )

1 22 2

2 2 24

o c o o c o

o o

R F F F R F F F

with F F

ω ω

ω σ

= minus = minus

=

⎡ ⎤⎣ ⎦⎡ ⎤⎣ ⎦

sum sum sum sum

















60 Spacing purpose


N1 08191(2) 033959(11) 044026(13) 00230(5)C1 10035(3) 01508(2) 01541(2) 00488(10)

H1A 09484 01603 01083 0073H1B 10538 01843 01681 0073H1C 09675 01431 01934 0073C2 09832(4) 03070(2) 02577(2) 00515(11)

H2A 09997 02888 02144 0077H2B 09955 0278 02979 0077H2C 10308 03415 02734 0077C3 04553(4) 04020(2) 03572(3) 00608(13)

H3A 03864 04166 03649 0091H3B 04434 03885 03062 0091H3C 05094 0434 0367 0091C4 01955(3) 024054(17) 04586(2) 00413(8)

H4A 02426 02658 04962 0062H4B 01277 02322 04725 0062H4C 01785 0261 04109 0062C5 10883(3) 012717(16) 059798(19) 00323(7)

H5A 11335 0135 05639 0048H5B 11351 01242 06484 0048H5C 10361 01597 05952 0048C6 04433(3) -014838(15) 043809(17) 00299(7)

H6A 04753 -01823 04186 0045H6B 03916 -01627 04649 0045H6C 05013 -01256 04716 0045C7 02943(3) 024899(16) 019299(18) 00328(7)

H7A 03206 02828 02256 0049H7B 03198 0212 02192 0049H7C 02143 02493 01779 0049C8 02850(3) -007793(18) 000945(19) 00366(8)

H8A 02428 -00414 -00046 0055H8B 02828 -00896 00593 0055H8C 02535 -01096 -00253 0055C9 04032(3) 010941(13) -003200(16) 00239(6)

H9A 03998 00979 00182 0029H9B 03804 00745 -00644 0029C10 03390(3) 025358(14) 012340(17) 00259(6)


61


H10B 0314 02914 00975 0031C11 11095(2) 000596(14) 039549(16) 00231(6)

H11A 11574 00004 04458 0028H11B 10553 00369 03984 0028C12 08384(3) 028833(13) 049776(16) 00241(6)

H12A 09175 02794 05126 0029H12B 08007 02525 04731 0029C13 08622(3) 032742(15) 023751(17) 00303(7)

H13A 08147 02926 02203 0036H13B 08501 03561 01962 0036C14 10257(3) 006821(15) 057650(16) 00255(6)

H14A 10787 00356 05782 0031H14B 09795 00712 05253 0031C15 03285(3) -005269(14) 039924(16) 00249(6)

H15A 03857 -00255 04273 003H15B 02829 -00655 0432 003C16 07492(2) -008206(14) 061545(16) 00236(6)

H16A 07076 -00688 05659 0028H16B 06958 -00925 06435 0028C17 03820(3) -010764(14) 037276(16) 00261(6)

H17A 04343 -00939 03453 0031H17B 03247 -01312 03385 0031C18 10477(3) -005319(14) 037066(16) 00249(6)

H18A 11007 -00857 03719 003H18B 10018 -00493 03194 003C19 04049(3) -006711(14) 000779(17) 00271(6)

H19A 04359 -00346 00423 0033H19B 04065 -00545 -00424 0033C20 02555(3) 018113(15) 045266(18) 00300(7)

H20A 03249 01899 044 0036H20B 02733 01608 05011 0036C21 02566(3) -002023(14) 033016(16) 00241(6)

H21A 03055 -00026 03026 0029H21B 02111 -00503 02977 0029


Spacing purpose

62


H22A 05503 0156 00069 0031H22B 05277 01384 -00785 0031C23 08001(3) 029944(14) 056911(16) 00243(6)

H23A 07195 03026 05566 0029H23B 08314 03371 05926 0029C24 11024(2) 004903(15) 027077(16) 00248(6)

H24A 10572 00145 02489 003H24B 10525 00797 02811 003C25 07036(3) 036725(14) 042883(17) 00264(6)

H25A 06953 03997 03923 0032H25B 06985 0385 0476 0032C26 06671(3) -018783(13) 013254(15) 00244(6)

H26A 07249 -0218 01498 0029H26B 0596 -02086 01219 0029C27 10680(3) 009479(19) 014209(19) 00405(9)

H27A 11036 0103 01021 0049H27B 10158 00618 01255 0049C28 08147(3) -013913(15) 060667(18) 00295(7)

H28A 08816 -01277 05922 0035H28B 0837 -01602 06545 0035C29 11574(3) 007416(17) 021252(18) 00324(7)

H29A 12038 00432 01987 0039H29B 12045 01082 02336 0039C30 04971(3) 034978(17) 04101(2) 00378(8)

H30A 0441 03181 04007 0045H30B 05071 03636 04614 0045C31 06073(3) 032287(16) 040217(19) 00327(7)

H31A 06232 02859 04315 0039H31B 06001 03126 03499 0039C32 06722(3) -014281(14) 019599(16) 00283(7)

H32A 06229 -0109 01771 0034H32B 07473 -01271 02135 0034





64



O4 ZR2 O107 10238O107 ZR4 O1 10278

O1 ZR4 O101 1035O101 ZR5 O2 10303

O2 ZR5 O104 10309O104 ZR3 O5 10424












Figure 5 a) and b)












66















discussed herein


68 35 Discussion

























reference























352 Mass Spectra







diffraction









MALDI first
























and 866 amu






























assigned




















353 Classification




























11 a) M6X8L6144-150




76












Scheme 2 (favored)










follows



































356 Prospects


























































were present

83

















84



























O + RO CH 16 13 -16 -22 -2 -3 -42 -22 -28 828O CH2 16 14 -10 -16 -2 -2 -36 -16 -22 834

CH O 13 16 -4 -10 -1 -2 -24 -4 -10 810CH2 O 14 16 -16 -22 -2 -2 -36 -16 -22 822


-1 -2 -24-2 -1 -30-1 -1 -18-2 -2 -36

-1 -2 -24-1 -1 -18-1 -1 -18-2 -1 -30

-2 -2 -36-2 -1 -30-1 -2 -24-2 -2 -36


L12 X6 mascharge



O + RO CH 16 13 -14 -20 -2 -3 -42 -20 -26 830O CH2 16 14 -8 -14 -2 -2 -36 -14 -20 836

CH O 13 16 -2 -8 -1 -2 -24 -2 -8 812CH2 O 14 16 -14 -20 -2 -2 -36 -14 -20 824

-1 -2 -24-2 -1 -30-1 -1 -18-2 -2 -36

-1 -2 -24-1 -1 -18-1 -1 -18-2 -1 -30

-2 -2 -36-2 -1 -30-1 -2 -24-2 -2 -36


86




principle)











































36 Conclusions






































proofreading





the manuscript












DrMallouk Lab space





appreciated

38 References


14 (2) 97-113






347 (6291) 354-358


1993 8 (8) 2054-2097







7568


Society 1996 118 (2) 446-450



1466


10903


5423


Physics 2003 118 (17) 7737-7740


2004 108 (49) 18796-18798


121 (21) 10321-10324


Chemical 2005 239 (1-2) 116-124


119 (32) 7417-7422


19211-19214


Science 1993 260 (5105) 195-196


1994 13 (8) 1197-1223


186


2) 1-78






9122-9134




2002 6 (4) 337-345


(5056) 515-516


104 (9) 3893-3946




Edition 1999 38 (21) 3165-3168








Elsevier 1994


1531-1532




8469




107 (15) 4571-4573


109 (16) 4844-4850


2) 21-34


67





575-587





(16) 4618-4619


(8) 1927-1934

57 Smith J D C J D JACS 1985 107 (5704)


312





2171-2177









Compounds 1998 278 (1-2) 123-129



domain In






1991 598 (7-8) 363-370


619




553-556





(12) 1777-1779




527


Society 1998 120 (44) 11391-11400


116 (17) 7909-7910



Chemie 1996 622 (3) 425-431






2988-2994


(1-2) 239-250


4047-4054








1996-2003





2006 18 10521


Freeman 2005


Polyhedron 1999 18 (6) 787-792




17-21









(1-3) 181-187





Spectrometry 2007 265 (1) 15-22







Co KGaA 2007



(12) 1088






379








Science 1978 34 (JUN) 1764-1770


2963-2968




(3589)



(26) 10944





477


Transactions 1999 (8) 1301-1305


1-7








4532-4535




Chemistry 1970 9 (6) 134





2002 (5) 1198-1202




1986 108 (9) 2474-2476


2003 22 (12) 1553-1559





(2) 285-295













2019



114 (15) 6152-6158


Spectrometry 1992 3 (4) 464-466




271


312








(19) 627-627




single bond In 2008


2541-2550





Chemistry 1984 56 (1) 25-33


Society 1978 100 (11) 3611-3613



565




(20) 1995-1996




2006 632 (12-13) 1956-1958


3498-3512

103 Chapter 4



41 Abstract















104 42 Introduction













materials













(vide infra)












































43 Experimental









108













well


















V35




















433 Calculation










discussion is given

112 44 Results
























b) Equation 4-1


(3421 mz)





















































h

a) 15 mont













of trideagold







119


Au11 series

eds

Au13 series

Au12 series


120

Clusters+ Mass (mz)

Oxygen Adduction







Au13(depp)Cl4(PPh3)3(P1)3 3974 1 8e 1212


121




MassLynx 3 080

Figure 4-5b

Figure 4-5c

(3117mz) [Au12(depp)4Cl3]+

(depp) Cl ]3 4 4+ (3583 mz) and





443 31P-NMR








123








ratio)






















[P1(1+2+3) ] [PPh3(1+2+3)] = 43 1











444 TEM


























127


Spacing purpose

128






are shown below
























45 Discussion














































etc40




















































from Au9+ to Au13

















137















MPCs is made here












raised24 67


















phase































section)








[Pd561(phen)60](OAc)18099





















143 46 Future Work















halide anions45

47 Conclusions

















48 Acknowledgements



















4-9 References





9266-9272








W Du K Du A 2007


Lizishu 2006 (18(9)) 1515-1518



4943










Society 2006 128 (1) 257-264





2006



14627


7493







(14) 4046-4047


8126


23 (4) 2247-2254







Sciences 2001 56 (8) 728-734





Chemistry B 2006 110 (43) 21416-21418




121 (4) 882-883




(51) 15742-15743














(5) 561-566


1994 33 (2) 207-209


ASAP




Science 2007 318 (5849) 430-433


Society 1997 119 (39) 9175-9178










1989 246 (4926) 64-71






1995 231 (1-2) 65-71




(23) 8195-8201




















325










2008


Chemistry B 2006 110 (24) 11611-11614








2004




2000 33 (3) 657-659












(13) 1163-1169




11600











999


2002 106 (39) 9979-9981









428


304 (5667) 84-87


1413

153

Chapter 5

Conclusion Remarks







learning































155 References











156

Appendix A












this Appendix














purpose













stated the paradox

158










159









160

100nm

100nm


100nm

161


















162


Zr 3d25

ZrO2 3d52

ZrO2 3d32

ZrC 3d 32

Zr() 3d52

Zr() 3d32

Zr() 3d32

Zrdeg 3d52

Zrdeg 3d52

Zrdeg 3d32


Zrdeg 3d32

Pos1820918450180531829417855180961766717907

Area297441982422114147325452363427011799

Zr 3

d

x 102

6

8

10

12

14

16

18

20

22

24

26

CPS









costly

















164


20nm






165



NOVA (problem)


Improvement





higher cluster flux




control no gas)


gas matrix









property No




166




A5 Acknowledgements





A6 References




and Technology 2000 8 (1-2) 27-38


Science 1993 260 (5105) 195-196


156


8579-8587








colleague In 2005





(15) 3497-3511



1997 119 (32) 7417-7422




2005 123 (15)


1992 256 (5058) 818-820


13-21





PA 2006

169

Appendix B












NMR (Figure B5-B8)








































following equation







175




Oxidation induced

middotP2 + middotP1


[Au13(depp)3(P1)(

[Au13(depp)2(P1)2(P

[Au13(depp)(P1)3(P


3[Au13(depp)4

[Au13(depp)4

















listed below

177 Electron


2 O2

3 O3

4 O4

3351 1 O

2 O2

O3

1O4

1 1






2 6O2





3583 1 O

2 O2

3 O3

4 O4

1 4O


4 O45 O5

6 O6




9 O9


6 O6



3 O3

4 O45 3 3963 3965 Au13Cl5P11C56H134 Π Fig4-6 c

Au13 13 6 3 3986 3988 Au13Cl3P12C66H1565 O5

radic Fig4-6 c

Electron



elimi 13 3 1 4 3 1 3990 3992

3583plus O

plus O

plus O



simulations



179 Spacing Purpose



f) 3714 mz


180



i) 3987 mz


181










behaviors11




182























183 B7 References




Chemistry B 2006 110 (43) 21416-21418


Chemistry B 2002 106 (39) 9979-9981











KGaA Weinheim 2004



14664-14669






(1) 993-999






237-325


165





185 Appendix C



Low M

ass Limit (m

z) 8041


Hershey PA

VITA

Lin Gao


Academia





Abstract



12 Motivation


14 References


21 Abstract

22 Introduction

23 Experimental

24 Results

25 Discussion

26 Conclusion

27 Acknowledgements

28 References


31 Abstract

32 Introduction

33 Experimental






34 Results




3431 By-products



35 Discussion


352 Mass Spectra

353 Classification



356 Prospects



36 Conclusions

37 Acknowledgements

38 References

41 Abstract

42 Introduction

43 Experimental



433 Calculation

44 Results



443 31P-NMR

444 TEM

45 Discussion






46 Future Work

47 Conclusions

48 Acknowledgements

4-9 References

Chapter 5

Conclusion Remarks

References

Appendix A






A5 Acknowledgements

A6 References

Appendix B







B7 References

Appendix C


iii

Abstract






























































the SAAs



















Chapter 5 153


References155

Appendix A156



Appendix B 169



Appendix C185


ix List of Figures




m n+

4 12 5


8 1240 7


45

2 2 8


h

49 8



8 12

c60 10



20

23





27

d30



X )

696 12 6

m-

52 i

a 44




6 14 4101 53


6 12 6n-

4

56


6 12 6n-

4

58


micro i oxo

micro 64



6 12 62-

66


6 12 6-

67




6105 81


6 5 3 2 5 3 7108


11 3 3 2 2+

11 4 2+

11 3 3 2 2+ 113


3 3114



11 4 2+

12 4 3+

13 4 4+ 117




11 4 2+

12 4 3+

13 4 4+

13 4 4+

13 4 4+

80 121



31

3 3 123






13 4 4+

11 12

1370137



64

142



9

8

158


10

159



2

2

162












1

176





1

185

xv

List of Tables











457


4 59


4 60


4 61


4 62


4 63



























































my miracle

xix Dedicated To

My dear families

Mentors and friends

Chapter 1

Introduction






















(Figure 1-1)



















































12 Motivation




transition metals






























7











8












+
























motivations

11







therein








































14 References




Bowl 2007 Vol 59 p 64-64




Processes 1992 118 167-189




Physics 1981 74 (11) 6511-6512



1985 318 (6042) 162-163


999



1413


256 (5056) 515-516




2004 304 (5667) 84-87




New York 1994



20 Pauli W Science 1946 103 (2669) 213-215








(4) 569-572



122-128


Matter 2006 18 (41) 9509-9517




105-110


115 (15) 6958-6961


Science 1993 260 (5105) 195-196


Physics 1997 106 (6) 2231-2238


(51) 10486-10492




Engineering 2006 14 (4) 637-646


(6) 893-901


Compounds 2007 433 (1-2) 79-83


495-542




2005 123 (15)


2006 252 (19) 6463-6465


Physics Letters 2004 398 (4-6) 292-296


115 (10) 4395-4396


3497-3511


Review Letters 1999 83 (24) 4983-4986


Letters 2001 349 (3-4) 220-226



256 (5058) 818-820






Chemistry A 2006 110 (10) 3505-3513


Chemical 2005 239 (1-2) 116-124


2004 108 (49) 18796-18798


10903


Physics 2006 124 (16)



15 (25) 4341-4348


Physics Letters 2006 425 (4-6) 273-277









14627




18

Chapter 2



21 Abstract














diffraction








20

22 Introduction
















packing motifs
























22 23 Experimental














23

















24 Results

















1 relative errors

i hkl 3

Ri (mm) (Reciprocal



θri-r12 (Inter-

planar angle)

DiD1 (Spacing

Ratio)












27


(A)

(B)

+ [361]

(-313)

(-420)

(-11-3)

(3-1-3)

(4-20)

(1-13)








28

i hkl 2

Ri (mm) (Reciprocal



θri-r11 (Inter-

planar angle)

DiD1 (Spacing







25 Discussion



d cong λLr (1)





















30






confidence





present experiments



below)



467(11) 311 (11) frac12 1548(36) 348(6) 331 (19) frac12 1515(26) 344(6) 420 (20) frac12 1538(27)




Spacing



Radii Ratio


15













+4 068 080 12 0 149 160 11









atoms










26 Conclusion







assembly




























28 References




(16)



(5200) 999-1001


19211-19214


119 (32) 7417-7422



1413


Science 1993 260 (5105) 195-196


1957






(42) 7695-7698





256 (5058) 818-820


495-542







Society 1993 115 (16) 7415-7418






PA 2006








1954-1955

38

Chapter 3



31 Abstract













39 32 Introduction





































































In summary


Number of


Interaction Types

(Met-Cars-L)





complexation

111


























































46 33 Experimental





































































package99










































34 Results







reported101

53














File Name (Log pg)


Starting

material Note


supernatant

jlg2 (pg B42)


a ZrC soot clear


jlg5


90deg V=1203Aring3




3431 By-products








File Name (Log pg)

Lattice Constant


Note


(a b c)(αβ γ)(V)


591 Aring3



brown top

phase c

(a b c)(αβ


90deg 90deg 90deg

1373 Aring3


top phase c

(a b c)(αβ γ)(V)


916deg 520 Aring3













2[N(nBu)4]







[ ] ( )

( )

1 22 2

2 2 24

o c o o c o

o o

R F F F R F F F

with F F

ω ω

ω σ

= minus = minus

=

⎡ ⎤⎣ ⎦⎡ ⎤⎣ ⎦

sum sum sum sum

















60 Spacing purpose


N1 08191(2) 033959(11) 044026(13) 00230(5)C1 10035(3) 01508(2) 01541(2) 00488(10)

H1A 09484 01603 01083 0073H1B 10538 01843 01681 0073H1C 09675 01431 01934 0073C2 09832(4) 03070(2) 02577(2) 00515(11)

H2A 09997 02888 02144 0077H2B 09955 0278 02979 0077H2C 10308 03415 02734 0077C3 04553(4) 04020(2) 03572(3) 00608(13)

H3A 03864 04166 03649 0091H3B 04434 03885 03062 0091H3C 05094 0434 0367 0091C4 01955(3) 024054(17) 04586(2) 00413(8)

H4A 02426 02658 04962 0062H4B 01277 02322 04725 0062H4C 01785 0261 04109 0062C5 10883(3) 012717(16) 059798(19) 00323(7)

H5A 11335 0135 05639 0048H5B 11351 01242 06484 0048H5C 10361 01597 05952 0048C6 04433(3) -014838(15) 043809(17) 00299(7)

H6A 04753 -01823 04186 0045H6B 03916 -01627 04649 0045H6C 05013 -01256 04716 0045C7 02943(3) 024899(16) 019299(18) 00328(7)

H7A 03206 02828 02256 0049H7B 03198 0212 02192 0049H7C 02143 02493 01779 0049C8 02850(3) -007793(18) 000945(19) 00366(8)

H8A 02428 -00414 -00046 0055H8B 02828 -00896 00593 0055H8C 02535 -01096 -00253 0055C9 04032(3) 010941(13) -003200(16) 00239(6)

H9A 03998 00979 00182 0029H9B 03804 00745 -00644 0029C10 03390(3) 025358(14) 012340(17) 00259(6)


61


H10B 0314 02914 00975 0031C11 11095(2) 000596(14) 039549(16) 00231(6)

H11A 11574 00004 04458 0028H11B 10553 00369 03984 0028C12 08384(3) 028833(13) 049776(16) 00241(6)

H12A 09175 02794 05126 0029H12B 08007 02525 04731 0029C13 08622(3) 032742(15) 023751(17) 00303(7)

H13A 08147 02926 02203 0036H13B 08501 03561 01962 0036C14 10257(3) 006821(15) 057650(16) 00255(6)

H14A 10787 00356 05782 0031H14B 09795 00712 05253 0031C15 03285(3) -005269(14) 039924(16) 00249(6)

H15A 03857 -00255 04273 003H15B 02829 -00655 0432 003C16 07492(2) -008206(14) 061545(16) 00236(6)

H16A 07076 -00688 05659 0028H16B 06958 -00925 06435 0028C17 03820(3) -010764(14) 037276(16) 00261(6)

H17A 04343 -00939 03453 0031H17B 03247 -01312 03385 0031C18 10477(3) -005319(14) 037066(16) 00249(6)

H18A 11007 -00857 03719 003H18B 10018 -00493 03194 003C19 04049(3) -006711(14) 000779(17) 00271(6)

H19A 04359 -00346 00423 0033H19B 04065 -00545 -00424 0033C20 02555(3) 018113(15) 045266(18) 00300(7)

H20A 03249 01899 044 0036H20B 02733 01608 05011 0036C21 02566(3) -002023(14) 033016(16) 00241(6)

H21A 03055 -00026 03026 0029H21B 02111 -00503 02977 0029


Spacing purpose

62


H22A 05503 0156 00069 0031H22B 05277 01384 -00785 0031C23 08001(3) 029944(14) 056911(16) 00243(6)

H23A 07195 03026 05566 0029H23B 08314 03371 05926 0029C24 11024(2) 004903(15) 027077(16) 00248(6)

H24A 10572 00145 02489 003H24B 10525 00797 02811 003C25 07036(3) 036725(14) 042883(17) 00264(6)

H25A 06953 03997 03923 0032H25B 06985 0385 0476 0032C26 06671(3) -018783(13) 013254(15) 00244(6)

H26A 07249 -0218 01498 0029H26B 0596 -02086 01219 0029C27 10680(3) 009479(19) 014209(19) 00405(9)

H27A 11036 0103 01021 0049H27B 10158 00618 01255 0049C28 08147(3) -013913(15) 060667(18) 00295(7)

H28A 08816 -01277 05922 0035H28B 0837 -01602 06545 0035C29 11574(3) 007416(17) 021252(18) 00324(7)

H29A 12038 00432 01987 0039H29B 12045 01082 02336 0039C30 04971(3) 034978(17) 04101(2) 00378(8)

H30A 0441 03181 04007 0045H30B 05071 03636 04614 0045C31 06073(3) 032287(16) 040217(19) 00327(7)

H31A 06232 02859 04315 0039H31B 06001 03126 03499 0039C32 06722(3) -014281(14) 019599(16) 00283(7)

H32A 06229 -0109 01771 0034H32B 07473 -01271 02135 0034





64



O4 ZR2 O107 10238O107 ZR4 O1 10278

O1 ZR4 O101 1035O101 ZR5 O2 10303

O2 ZR5 O104 10309O104 ZR3 O5 10424












Figure 5 a) and b)












66















discussed herein


68 35 Discussion

























reference























352 Mass Spectra







diffraction









MALDI first
























and 866 amu






























assigned




















353 Classification




























11 a) M6X8L6144-150




76












Scheme 2 (favored)










follows



































356 Prospects


























































were present

83

















84



























O + RO CH 16 13 -16 -22 -2 -3 -42 -22 -28 828O CH2 16 14 -10 -16 -2 -2 -36 -16 -22 834

CH O 13 16 -4 -10 -1 -2 -24 -4 -10 810CH2 O 14 16 -16 -22 -2 -2 -36 -16 -22 822


-1 -2 -24-2 -1 -30-1 -1 -18-2 -2 -36

-1 -2 -24-1 -1 -18-1 -1 -18-2 -1 -30

-2 -2 -36-2 -1 -30-1 -2 -24-2 -2 -36


L12 X6 mascharge



O + RO CH 16 13 -14 -20 -2 -3 -42 -20 -26 830O CH2 16 14 -8 -14 -2 -2 -36 -14 -20 836

CH O 13 16 -2 -8 -1 -2 -24 -2 -8 812CH2 O 14 16 -14 -20 -2 -2 -36 -14 -20 824

-1 -2 -24-2 -1 -30-1 -1 -18-2 -2 -36

-1 -2 -24-1 -1 -18-1 -1 -18-2 -1 -30

-2 -2 -36-2 -1 -30-1 -2 -24-2 -2 -36


86




principle)











































36 Conclusions






































proofreading





the manuscript












DrMallouk Lab space





appreciated

38 References


14 (2) 97-113






347 (6291) 354-358


1993 8 (8) 2054-2097







7568


Society 1996 118 (2) 446-450



1466


10903


5423


Physics 2003 118 (17) 7737-7740


2004 108 (49) 18796-18798


121 (21) 10321-10324


Chemical 2005 239 (1-2) 116-124


119 (32) 7417-7422


19211-19214


Science 1993 260 (5105) 195-196


1994 13 (8) 1197-1223


186


2) 1-78






9122-9134




2002 6 (4) 337-345


(5056) 515-516


104 (9) 3893-3946




Edition 1999 38 (21) 3165-3168








Elsevier 1994


1531-1532




8469




107 (15) 4571-4573


109 (16) 4844-4850


2) 21-34


67





575-587





(16) 4618-4619


(8) 1927-1934

57 Smith J D C J D JACS 1985 107 (5704)


312





2171-2177









Compounds 1998 278 (1-2) 123-129



domain In






1991 598 (7-8) 363-370


619




553-556





(12) 1777-1779




527


Society 1998 120 (44) 11391-11400


116 (17) 7909-7910



Chemie 1996 622 (3) 425-431






2988-2994


(1-2) 239-250


4047-4054








1996-2003





2006 18 10521


Freeman 2005


Polyhedron 1999 18 (6) 787-792




17-21









(1-3) 181-187





Spectrometry 2007 265 (1) 15-22







Co KGaA 2007



(12) 1088






379








Science 1978 34 (JUN) 1764-1770


2963-2968




(3589)



(26) 10944





477


Transactions 1999 (8) 1301-1305


1-7








4532-4535




Chemistry 1970 9 (6) 134





2002 (5) 1198-1202




1986 108 (9) 2474-2476


2003 22 (12) 1553-1559





(2) 285-295













2019



114 (15) 6152-6158


Spectrometry 1992 3 (4) 464-466




271


312








(19) 627-627




single bond In 2008


2541-2550





Chemistry 1984 56 (1) 25-33


Society 1978 100 (11) 3611-3613



565




(20) 1995-1996




2006 632 (12-13) 1956-1958


3498-3512

103 Chapter 4



41 Abstract















104 42 Introduction













materials













(vide infra)












































43 Experimental









108













well


















V35




















433 Calculation










discussion is given

112 44 Results
























b) Equation 4-1


(3421 mz)





















































h

a) 15 mont













of trideagold







119


Au11 series

eds

Au13 series

Au12 series


120

Clusters+ Mass (mz)

Oxygen Adduction







Au13(depp)Cl4(PPh3)3(P1)3 3974 1 8e 1212


121




MassLynx 3 080

Figure 4-5b

Figure 4-5c

(3117mz) [Au12(depp)4Cl3]+

(depp) Cl ]3 4 4+ (3583 mz) and





443 31P-NMR








123








ratio)






















[P1(1+2+3) ] [PPh3(1+2+3)] = 43 1











444 TEM


























127


Spacing purpose

128






are shown below
























45 Discussion














































etc40




















































from Au9+ to Au13

















137















MPCs is made here












raised24 67


















phase































section)








[Pd561(phen)60](OAc)18099





















143 46 Future Work















halide anions45

47 Conclusions

















48 Acknowledgements



















4-9 References





9266-9272








W Du K Du A 2007


Lizishu 2006 (18(9)) 1515-1518



4943










Society 2006 128 (1) 257-264





2006



14627


7493







(14) 4046-4047


8126


23 (4) 2247-2254







Sciences 2001 56 (8) 728-734





Chemistry B 2006 110 (43) 21416-21418




121 (4) 882-883




(51) 15742-15743














(5) 561-566


1994 33 (2) 207-209


ASAP




Science 2007 318 (5849) 430-433


Society 1997 119 (39) 9175-9178










1989 246 (4926) 64-71






1995 231 (1-2) 65-71




(23) 8195-8201




















325










2008


Chemistry B 2006 110 (24) 11611-11614








2004




2000 33 (3) 657-659












(13) 1163-1169




11600











999


2002 106 (39) 9979-9981









428


304 (5667) 84-87


1413

153

Chapter 5

Conclusion Remarks







learning































155 References











156

Appendix A












this Appendix














purpose













stated the paradox

158










159









160

100nm

100nm


100nm

161


















162


Zr 3d25

ZrO2 3d52

ZrO2 3d32

ZrC 3d 32

Zr() 3d52

Zr() 3d32

Zr() 3d32

Zrdeg 3d52

Zrdeg 3d52

Zrdeg 3d32


Zrdeg 3d32

Pos1820918450180531829417855180961766717907

Area297441982422114147325452363427011799

Zr 3

d

x 102

6

8

10

12

14

16

18

20

22

24

26

CPS









costly

















164


20nm






165



NOVA (problem)


Improvement





higher cluster flux




control no gas)


gas matrix









property No




166




A5 Acknowledgements





A6 References




and Technology 2000 8 (1-2) 27-38


Science 1993 260 (5105) 195-196


156


8579-8587








colleague In 2005





(15) 3497-3511



1997 119 (32) 7417-7422




2005 123 (15)


1992 256 (5058) 818-820


13-21





PA 2006

169

Appendix B












NMR (Figure B5-B8)








































following equation







175




Oxidation induced

middotP2 + middotP1


[Au13(depp)3(P1)(

[Au13(depp)2(P1)2(P

[Au13(depp)(P1)3(P


3[Au13(depp)4

[Au13(depp)4

















listed below

177 Electron


2 O2

3 O3

4 O4

3351 1 O

2 O2

O3

1O4

1 1






2 6O2





3583 1 O

2 O2

3 O3

4 O4

1 4O


4 O45 O5

6 O6




9 O9


6 O6



3 O3

4 O45 3 3963 3965 Au13Cl5P11C56H134 Π Fig4-6 c

Au13 13 6 3 3986 3988 Au13Cl3P12C66H1565 O5

radic Fig4-6 c

Electron



elimi 13 3 1 4 3 1 3990 3992

3583plus O

plus O

plus O



simulations



179 Spacing Purpose



f) 3714 mz


180



i) 3987 mz


181










behaviors11




182























183 B7 References




Chemistry B 2006 110 (43) 21416-21418


Chemistry B 2002 106 (39) 9979-9981











KGaA Weinheim 2004



14664-14669






(1) 993-999






237-325


165





185 Appendix C



Low M

ass Limit (m

z) 8041


Hershey PA

VITA

Lin Gao


Academia





Abstract



12 Motivation


14 References


21 Abstract

22 Introduction

23 Experimental

24 Results

25 Discussion

26 Conclusion

27 Acknowledgements

28 References


31 Abstract

32 Introduction

33 Experimental






34 Results




3431 By-products



35 Discussion


352 Mass Spectra

353 Classification



356 Prospects



36 Conclusions

37 Acknowledgements

38 References

41 Abstract

42 Introduction

43 Experimental



433 Calculation

44 Results



443 31P-NMR

444 TEM

45 Discussion






46 Future Work

47 Conclusions

48 Acknowledgements

4-9 References

Chapter 5

Conclusion Remarks

References

Appendix A






A5 Acknowledgements

A6 References

Appendix B







B7 References

Appendix C













































the SAAs



















Chapter 5 153


References155

Appendix A156



Appendix B 169



Appendix C185


ix List of Figures




m n+

4 12 5


8 1240 7


45

2 2 8


h

49 8



8 12

c60 10



20

23





27

d30



X )

696 12 6

m-

52 i

a 44




6 14 4101 53


6 12 6n-

4

56


6 12 6n-

4

58


micro i oxo

micro 64



6 12 62-

66


6 12 6-

67




6105 81


6 5 3 2 5 3 7108


11 3 3 2 2+

11 4 2+

11 3 3 2 2+ 113


3 3114



11 4 2+

12 4 3+

13 4 4+ 117




11 4 2+

12 4 3+

13 4 4+

13 4 4+

13 4 4+

80 121



31

3 3 123






13 4 4+

11 12

1370137



64

142



9

8

158


10

159



2

2

162












1

176





1

185

xv

List of Tables











457


4 59


4 60


4 61


4 62


4 63



























































my miracle

xix Dedicated To

My dear families

Mentors and friends

Chapter 1

Introduction






















(Figure 1-1)



















































12 Motivation




transition metals






























7











8












+
























motivations

11







therein








































14 References




Bowl 2007 Vol 59 p 64-64




Processes 1992 118 167-189




Physics 1981 74 (11) 6511-6512



1985 318 (6042) 162-163


999



1413


256 (5056) 515-516




2004 304 (5667) 84-87




New York 1994



20 Pauli W Science 1946 103 (2669) 213-215








(4) 569-572



122-128


Matter 2006 18 (41) 9509-9517




105-110


115 (15) 6958-6961


Science 1993 260 (5105) 195-196


Physics 1997 106 (6) 2231-2238


(51) 10486-10492




Engineering 2006 14 (4) 637-646


(6) 893-901


Compounds 2007 433 (1-2) 79-83


495-542




2005 123 (15)


2006 252 (19) 6463-6465


Physics Letters 2004 398 (4-6) 292-296


115 (10) 4395-4396


3497-3511


Review Letters 1999 83 (24) 4983-4986


Letters 2001 349 (3-4) 220-226



256 (5058) 818-820






Chemistry A 2006 110 (10) 3505-3513


Chemical 2005 239 (1-2) 116-124


2004 108 (49) 18796-18798


10903


Physics 2006 124 (16)



15 (25) 4341-4348


Physics Letters 2006 425 (4-6) 273-277









14627




18

Chapter 2



21 Abstract














diffraction








20

22 Introduction
















packing motifs
























22 23 Experimental














23

















24 Results

















1 relative errors

i hkl 3

Ri (mm) (Reciprocal



θri-r12 (Inter-

planar angle)

DiD1 (Spacing

Ratio)












27


(A)

(B)

+ [361]

(-313)

(-420)

(-11-3)

(3-1-3)

(4-20)

(1-13)








28

i hkl 2

Ri (mm) (Reciprocal



θri-r11 (Inter-

planar angle)

DiD1 (Spacing







25 Discussion



d cong λLr (1)





















30






confidence





present experiments



below)



467(11) 311 (11) frac12 1548(36) 348(6) 331 (19) frac12 1515(26) 344(6) 420 (20) frac12 1538(27)




Spacing



Radii Ratio


15













+4 068 080 12 0 149 160 11









atoms










26 Conclusion







assembly




























28 References




(16)



(5200) 999-1001


19211-19214


119 (32) 7417-7422



1413


Science 1993 260 (5105) 195-196


1957






(42) 7695-7698





256 (5058) 818-820


495-542







Society 1993 115 (16) 7415-7418






PA 2006








1954-1955

38

Chapter 3



31 Abstract













39 32 Introduction





































































In summary


Number of


Interaction Types

(Met-Cars-L)





complexation

111


























































46 33 Experimental





































































package99










































34 Results







reported101

53














File Name (Log pg)


Starting

material Note


supernatant

jlg2 (pg B42)


a ZrC soot clear


jlg5


90deg V=1203Aring3




3431 By-products








File Name (Log pg)

Lattice Constant


Note


(a b c)(αβ γ)(V)


591 Aring3



brown top

phase c

(a b c)(αβ


90deg 90deg 90deg

1373 Aring3


top phase c

(a b c)(αβ γ)(V)


916deg 520 Aring3













2[N(nBu)4]







[ ] ( )

( )

1 22 2

2 2 24

o c o o c o

o o

R F F F R F F F

with F F

ω ω

ω σ

= minus = minus

=

⎡ ⎤⎣ ⎦⎡ ⎤⎣ ⎦

sum sum sum sum

















60 Spacing purpose


N1 08191(2) 033959(11) 044026(13) 00230(5)C1 10035(3) 01508(2) 01541(2) 00488(10)

H1A 09484 01603 01083 0073H1B 10538 01843 01681 0073H1C 09675 01431 01934 0073C2 09832(4) 03070(2) 02577(2) 00515(11)

H2A 09997 02888 02144 0077H2B 09955 0278 02979 0077H2C 10308 03415 02734 0077C3 04553(4) 04020(2) 03572(3) 00608(13)

H3A 03864 04166 03649 0091H3B 04434 03885 03062 0091H3C 05094 0434 0367 0091C4 01955(3) 024054(17) 04586(2) 00413(8)

H4A 02426 02658 04962 0062H4B 01277 02322 04725 0062H4C 01785 0261 04109 0062C5 10883(3) 012717(16) 059798(19) 00323(7)

H5A 11335 0135 05639 0048H5B 11351 01242 06484 0048H5C 10361 01597 05952 0048C6 04433(3) -014838(15) 043809(17) 00299(7)

H6A 04753 -01823 04186 0045H6B 03916 -01627 04649 0045H6C 05013 -01256 04716 0045C7 02943(3) 024899(16) 019299(18) 00328(7)

H7A 03206 02828 02256 0049H7B 03198 0212 02192 0049H7C 02143 02493 01779 0049C8 02850(3) -007793(18) 000945(19) 00366(8)

H8A 02428 -00414 -00046 0055H8B 02828 -00896 00593 0055H8C 02535 -01096 -00253 0055C9 04032(3) 010941(13) -003200(16) 00239(6)

H9A 03998 00979 00182 0029H9B 03804 00745 -00644 0029C10 03390(3) 025358(14) 012340(17) 00259(6)


61


H10B 0314 02914 00975 0031C11 11095(2) 000596(14) 039549(16) 00231(6)

H11A 11574 00004 04458 0028H11B 10553 00369 03984 0028C12 08384(3) 028833(13) 049776(16) 00241(6)

H12A 09175 02794 05126 0029H12B 08007 02525 04731 0029C13 08622(3) 032742(15) 023751(17) 00303(7)

H13A 08147 02926 02203 0036H13B 08501 03561 01962 0036C14 10257(3) 006821(15) 057650(16) 00255(6)

H14A 10787 00356 05782 0031H14B 09795 00712 05253 0031C15 03285(3) -005269(14) 039924(16) 00249(6)

H15A 03857 -00255 04273 003H15B 02829 -00655 0432 003C16 07492(2) -008206(14) 061545(16) 00236(6)

H16A 07076 -00688 05659 0028H16B 06958 -00925 06435 0028C17 03820(3) -010764(14) 037276(16) 00261(6)

H17A 04343 -00939 03453 0031H17B 03247 -01312 03385 0031C18 10477(3) -005319(14) 037066(16) 00249(6)

H18A 11007 -00857 03719 003H18B 10018 -00493 03194 003C19 04049(3) -006711(14) 000779(17) 00271(6)

H19A 04359 -00346 00423 0033H19B 04065 -00545 -00424 0033C20 02555(3) 018113(15) 045266(18) 00300(7)

H20A 03249 01899 044 0036H20B 02733 01608 05011 0036C21 02566(3) -002023(14) 033016(16) 00241(6)

H21A 03055 -00026 03026 0029H21B 02111 -00503 02977 0029


Spacing purpose

62


H22A 05503 0156 00069 0031H22B 05277 01384 -00785 0031C23 08001(3) 029944(14) 056911(16) 00243(6)

H23A 07195 03026 05566 0029H23B 08314 03371 05926 0029C24 11024(2) 004903(15) 027077(16) 00248(6)

H24A 10572 00145 02489 003H24B 10525 00797 02811 003C25 07036(3) 036725(14) 042883(17) 00264(6)

H25A 06953 03997 03923 0032H25B 06985 0385 0476 0032C26 06671(3) -018783(13) 013254(15) 00244(6)

H26A 07249 -0218 01498 0029H26B 0596 -02086 01219 0029C27 10680(3) 009479(19) 014209(19) 00405(9)

H27A 11036 0103 01021 0049H27B 10158 00618 01255 0049C28 08147(3) -013913(15) 060667(18) 00295(7)

H28A 08816 -01277 05922 0035H28B 0837 -01602 06545 0035C29 11574(3) 007416(17) 021252(18) 00324(7)

H29A 12038 00432 01987 0039H29B 12045 01082 02336 0039C30 04971(3) 034978(17) 04101(2) 00378(8)

H30A 0441 03181 04007 0045H30B 05071 03636 04614 0045C31 06073(3) 032287(16) 040217(19) 00327(7)

H31A 06232 02859 04315 0039H31B 06001 03126 03499 0039C32 06722(3) -014281(14) 019599(16) 00283(7)

H32A 06229 -0109 01771 0034H32B 07473 -01271 02135 0034





64



O4 ZR2 O107 10238O107 ZR4 O1 10278

O1 ZR4 O101 1035O101 ZR5 O2 10303

O2 ZR5 O104 10309O104 ZR3 O5 10424












Figure 5 a) and b)












66















discussed herein


68 35 Discussion

























reference























352 Mass Spectra







diffraction









MALDI first
























and 866 amu






























assigned




















353 Classification




























11 a) M6X8L6144-150




76












Scheme 2 (favored)










follows



































356 Prospects


























































were present

83

















84



























O + RO CH 16 13 -16 -22 -2 -3 -42 -22 -28 828O CH2 16 14 -10 -16 -2 -2 -36 -16 -22 834

CH O 13 16 -4 -10 -1 -2 -24 -4 -10 810CH2 O 14 16 -16 -22 -2 -2 -36 -16 -22 822


-1 -2 -24-2 -1 -30-1 -1 -18-2 -2 -36

-1 -2 -24-1 -1 -18-1 -1 -18-2 -1 -30

-2 -2 -36-2 -1 -30-1 -2 -24-2 -2 -36


L12 X6 mascharge



O + RO CH 16 13 -14 -20 -2 -3 -42 -20 -26 830O CH2 16 14 -8 -14 -2 -2 -36 -14 -20 836

CH O 13 16 -2 -8 -1 -2 -24 -2 -8 812CH2 O 14 16 -14 -20 -2 -2 -36 -14 -20 824

-1 -2 -24-2 -1 -30-1 -1 -18-2 -2 -36

-1 -2 -24-1 -1 -18-1 -1 -18-2 -1 -30

-2 -2 -36-2 -1 -30-1 -2 -24-2 -2 -36


86




principle)











































36 Conclusions






































proofreading





the manuscript












DrMallouk Lab space





appreciated

38 References


14 (2) 97-113






347 (6291) 354-358


1993 8 (8) 2054-2097







7568


Society 1996 118 (2) 446-450



1466


10903


5423


Physics 2003 118 (17) 7737-7740


2004 108 (49) 18796-18798


121 (21) 10321-10324


Chemical 2005 239 (1-2) 116-124


119 (32) 7417-7422


19211-19214


Science 1993 260 (5105) 195-196


1994 13 (8) 1197-1223


186


2) 1-78






9122-9134




2002 6 (4) 337-345


(5056) 515-516


104 (9) 3893-3946




Edition 1999 38 (21) 3165-3168








Elsevier 1994


1531-1532




8469




107 (15) 4571-4573


109 (16) 4844-4850


2) 21-34


67





575-587





(16) 4618-4619


(8) 1927-1934

57 Smith J D C J D JACS 1985 107 (5704)


312





2171-2177









Compounds 1998 278 (1-2) 123-129



domain In






1991 598 (7-8) 363-370


619




553-556





(12) 1777-1779




527


Society 1998 120 (44) 11391-11400


116 (17) 7909-7910



Chemie 1996 622 (3) 425-431






2988-2994


(1-2) 239-250


4047-4054








1996-2003





2006 18 10521


Freeman 2005


Polyhedron 1999 18 (6) 787-792




17-21









(1-3) 181-187





Spectrometry 2007 265 (1) 15-22







Co KGaA 2007



(12) 1088






379








Science 1978 34 (JUN) 1764-1770


2963-2968




(3589)



(26) 10944





477


Transactions 1999 (8) 1301-1305


1-7








4532-4535




Chemistry 1970 9 (6) 134





2002 (5) 1198-1202




1986 108 (9) 2474-2476


2003 22 (12) 1553-1559





(2) 285-295













2019



114 (15) 6152-6158


Spectrometry 1992 3 (4) 464-466




271


312








(19) 627-627




single bond In 2008


2541-2550





Chemistry 1984 56 (1) 25-33


Society 1978 100 (11) 3611-3613



565




(20) 1995-1996




2006 632 (12-13) 1956-1958


3498-3512

103 Chapter 4



41 Abstract















104 42 Introduction













materials













(vide infra)












































43 Experimental









108













well


















V35




















433 Calculation










discussion is given

112 44 Results
























b) Equation 4-1


(3421 mz)





















































h

a) 15 mont













of trideagold







119


Au11 series

eds

Au13 series

Au12 series


120

Clusters+ Mass (mz)

Oxygen Adduction







Au13(depp)Cl4(PPh3)3(P1)3 3974 1 8e 1212


121




MassLynx 3 080

Figure 4-5b

Figure 4-5c

(3117mz) [Au12(depp)4Cl3]+

(depp) Cl ]3 4 4+ (3583 mz) and





443 31P-NMR








123








ratio)






















[P1(1+2+3) ] [PPh3(1+2+3)] = 43 1











444 TEM


























127


Spacing purpose

128






are shown below
























45 Discussion














































etc40




















































from Au9+ to Au13

















137















MPCs is made here












raised24 67


















phase































section)








[Pd561(phen)60](OAc)18099





















143 46 Future Work















halide anions45

47 Conclusions

















48 Acknowledgements



















4-9 References





9266-9272








W Du K Du A 2007


Lizishu 2006 (18(9)) 1515-1518



4943










Society 2006 128 (1) 257-264





2006



14627


7493







(14) 4046-4047


8126


23 (4) 2247-2254







Sciences 2001 56 (8) 728-734





Chemistry B 2006 110 (43) 21416-21418




121 (4) 882-883




(51) 15742-15743














(5) 561-566


1994 33 (2) 207-209


ASAP




Science 2007 318 (5849) 430-433


Society 1997 119 (39) 9175-9178










1989 246 (4926) 64-71






1995 231 (1-2) 65-71




(23) 8195-8201




















325










2008


Chemistry B 2006 110 (24) 11611-11614








2004




2000 33 (3) 657-659












(13) 1163-1169




11600











999


2002 106 (39) 9979-9981









428


304 (5667) 84-87


1413

153

Chapter 5

Conclusion Remarks







learning































155 References











156

Appendix A












this Appendix














purpose













stated the paradox

158










159









160

100nm

100nm


100nm

161


















162


Zr 3d25

ZrO2 3d52

ZrO2 3d32

ZrC 3d 32

Zr() 3d52

Zr() 3d32

Zr() 3d32

Zrdeg 3d52

Zrdeg 3d52

Zrdeg 3d32


Zrdeg 3d32

Pos1820918450180531829417855180961766717907

Area297441982422114147325452363427011799

Zr 3

d

x 102

6

8

10

12

14

16

18

20

22

24

26

CPS









costly

















164


20nm






165



NOVA (problem)


Improvement





higher cluster flux




control no gas)


gas matrix









property No




166




A5 Acknowledgements





A6 References




and Technology 2000 8 (1-2) 27-38


Science 1993 260 (5105) 195-196


156


8579-8587








colleague In 2005





(15) 3497-3511



1997 119 (32) 7417-7422




2005 123 (15)


1992 256 (5058) 818-820


13-21





PA 2006

169

Appendix B












NMR (Figure B5-B8)








































following equation







175




Oxidation induced

middotP2 + middotP1


[Au13(depp)3(P1)(

[Au13(depp)2(P1)2(P

[Au13(depp)(P1)3(P


3[Au13(depp)4

[Au13(depp)4

















listed below

177 Electron


2 O2

3 O3

4 O4

3351 1 O

2 O2

O3

1O4

1 1






2 6O2





3583 1 O

2 O2

3 O3

4 O4

1 4O


4 O45 O5

6 O6




9 O9


6 O6



3 O3

4 O45 3 3963 3965 Au13Cl5P11C56H134 Π Fig4-6 c

Au13 13 6 3 3986 3988 Au13Cl3P12C66H1565 O5

radic Fig4-6 c

Electron



elimi 13 3 1 4 3 1 3990 3992

3583plus O

plus O

plus O



simulations



179 Spacing Purpose



f) 3714 mz


180



i) 3987 mz


181










behaviors11




182























183 B7 References




Chemistry B 2006 110 (43) 21416-21418


Chemistry B 2002 106 (39) 9979-9981











KGaA Weinheim 2004



14664-14669






(1) 993-999






237-325


165





185 Appendix C



Low M

ass Limit (m

z) 8041


Hershey PA

VITA

Lin Gao


Academia





Abstract



12 Motivation


14 References


21 Abstract

22 Introduction

23 Experimental

24 Results

25 Discussion

26 Conclusion

27 Acknowledgements

28 References


31 Abstract

32 Introduction

33 Experimental






34 Results




3431 By-products



35 Discussion


352 Mass Spectra

353 Classification



356 Prospects



36 Conclusions

37 Acknowledgements

38 References

41 Abstract

42 Introduction

43 Experimental



433 Calculation

44 Results



443 31P-NMR

444 TEM

45 Discussion






46 Future Work

47 Conclusions

48 Acknowledgements

4-9 References

Chapter 5

Conclusion Remarks

References

Appendix A






A5 Acknowledgements

A6 References

Appendix B







B7 References

Appendix C




















Chapter 5 153


References155

Appendix A156



Appendix B 169



Appendix C185


ix List of Figures




m n+

4 12 5


8 1240 7


45

2 2 8


h

49 8



8 12

c60 10



20

23





27

d30



X )

696 12 6

m-

52 i

a 44




6 14 4101 53


6 12 6n-

4

56


6 12 6n-

4

58


micro i oxo

micro 64



6 12 62-

66


6 12 6-

67




6105 81


6 5 3 2 5 3 7108


11 3 3 2 2+

11 4 2+

11 3 3 2 2+ 113


3 3114



11 4 2+

12 4 3+

13 4 4+ 117




11 4 2+

12 4 3+

13 4 4+

13 4 4+

13 4 4+

80 121



31

3 3 123






13 4 4+

11 12

1370137



64

142



9

8

158


10

159



2

2

162












1

176





1

185

xv

List of Tables











457


4 59


4 60


4 61


4 62


4 63



























































my miracle

xix Dedicated To

My dear families

Mentors and friends

Chapter 1

Introduction






















(Figure 1-1)



















































12 Motivation




transition metals






























7











8












+
























motivations

11







therein








































14 References




Bowl 2007 Vol 59 p 64-64




Processes 1992 118 167-189




Physics 1981 74 (11) 6511-6512



1985 318 (6042) 162-163


999



1413


256 (5056) 515-516




2004 304 (5667) 84-87




New York 1994



20 Pauli W Science 1946 103 (2669) 213-215








(4) 569-572



122-128


Matter 2006 18 (41) 9509-9517




105-110


115 (15) 6958-6961


Science 1993 260 (5105) 195-196


Physics 1997 106 (6) 2231-2238


(51) 10486-10492




Engineering 2006 14 (4) 637-646


(6) 893-901


Compounds 2007 433 (1-2) 79-83


495-542




2005 123 (15)


2006 252 (19) 6463-6465


Physics Letters 2004 398 (4-6) 292-296


115 (10) 4395-4396


3497-3511


Review Letters 1999 83 (24) 4983-4986


Letters 2001 349 (3-4) 220-226



256 (5058) 818-820






Chemistry A 2006 110 (10) 3505-3513


Chemical 2005 239 (1-2) 116-124


2004 108 (49) 18796-18798


10903


Physics 2006 124 (16)



15 (25) 4341-4348


Physics Letters 2006 425 (4-6) 273-277









14627




18

Chapter 2



21 Abstract














diffraction








20

22 Introduction
















packing motifs
























22 23 Experimental














23

















24 Results

















1 relative errors

i hkl 3

Ri (mm) (Reciprocal



θri-r12 (Inter-

planar angle)

DiD1 (Spacing

Ratio)












27


(A)

(B)

+ [361]

(-313)

(-420)

(-11-3)

(3-1-3)

(4-20)

(1-13)








28

i hkl 2

Ri (mm) (Reciprocal



θri-r11 (Inter-

planar angle)

DiD1 (Spacing







25 Discussion



d cong λLr (1)





















30






confidence





present experiments



below)



467(11) 311 (11) frac12 1548(36) 348(6) 331 (19) frac12 1515(26) 344(6) 420 (20) frac12 1538(27)




Spacing



Radii Ratio


15













+4 068 080 12 0 149 160 11









atoms










26 Conclusion







assembly




























28 References




(16)



(5200) 999-1001


19211-19214


119 (32) 7417-7422



1413


Science 1993 260 (5105) 195-196


1957






(42) 7695-7698





256 (5058) 818-820


495-542







Society 1993 115 (16) 7415-7418






PA 2006








1954-1955

38

Chapter 3



31 Abstract













39 32 Introduction





































































In summary


Number of


Interaction Types

(Met-Cars-L)





complexation

111


























































46 33 Experimental





































































package99










































34 Results







reported101

53














File Name (Log pg)


Starting

material Note


supernatant

jlg2 (pg B42)


a ZrC soot clear


jlg5


90deg V=1203Aring3




3431 By-products








File Name (Log pg)

Lattice Constant


Note


(a b c)(αβ γ)(V)


591 Aring3



brown top

phase c

(a b c)(αβ


90deg 90deg 90deg

1373 Aring3


top phase c

(a b c)(αβ γ)(V)


916deg 520 Aring3













2[N(nBu)4]







[ ] ( )

( )

1 22 2

2 2 24

o c o o c o

o o

R F F F R F F F

with F F

ω ω

ω σ

= minus = minus

=

⎡ ⎤⎣ ⎦⎡ ⎤⎣ ⎦

sum sum sum sum

















60 Spacing purpose


N1 08191(2) 033959(11) 044026(13) 00230(5)C1 10035(3) 01508(2) 01541(2) 00488(10)

H1A 09484 01603 01083 0073H1B 10538 01843 01681 0073H1C 09675 01431 01934 0073C2 09832(4) 03070(2) 02577(2) 00515(11)

H2A 09997 02888 02144 0077H2B 09955 0278 02979 0077H2C 10308 03415 02734 0077C3 04553(4) 04020(2) 03572(3) 00608(13)

H3A 03864 04166 03649 0091H3B 04434 03885 03062 0091H3C 05094 0434 0367 0091C4 01955(3) 024054(17) 04586(2) 00413(8)

H4A 02426 02658 04962 0062H4B 01277 02322 04725 0062H4C 01785 0261 04109 0062C5 10883(3) 012717(16) 059798(19) 00323(7)

H5A 11335 0135 05639 0048H5B 11351 01242 06484 0048H5C 10361 01597 05952 0048C6 04433(3) -014838(15) 043809(17) 00299(7)

H6A 04753 -01823 04186 0045H6B 03916 -01627 04649 0045H6C 05013 -01256 04716 0045C7 02943(3) 024899(16) 019299(18) 00328(7)

H7A 03206 02828 02256 0049H7B 03198 0212 02192 0049H7C 02143 02493 01779 0049C8 02850(3) -007793(18) 000945(19) 00366(8)

H8A 02428 -00414 -00046 0055H8B 02828 -00896 00593 0055H8C 02535 -01096 -00253 0055C9 04032(3) 010941(13) -003200(16) 00239(6)

H9A 03998 00979 00182 0029H9B 03804 00745 -00644 0029C10 03390(3) 025358(14) 012340(17) 00259(6)


61


H10B 0314 02914 00975 0031C11 11095(2) 000596(14) 039549(16) 00231(6)

H11A 11574 00004 04458 0028H11B 10553 00369 03984 0028C12 08384(3) 028833(13) 049776(16) 00241(6)

H12A 09175 02794 05126 0029H12B 08007 02525 04731 0029C13 08622(3) 032742(15) 023751(17) 00303(7)

H13A 08147 02926 02203 0036H13B 08501 03561 01962 0036C14 10257(3) 006821(15) 057650(16) 00255(6)

H14A 10787 00356 05782 0031H14B 09795 00712 05253 0031C15 03285(3) -005269(14) 039924(16) 00249(6)

H15A 03857 -00255 04273 003H15B 02829 -00655 0432 003C16 07492(2) -008206(14) 061545(16) 00236(6)

H16A 07076 -00688 05659 0028H16B 06958 -00925 06435 0028C17 03820(3) -010764(14) 037276(16) 00261(6)

H17A 04343 -00939 03453 0031H17B 03247 -01312 03385 0031C18 10477(3) -005319(14) 037066(16) 00249(6)

H18A 11007 -00857 03719 003H18B 10018 -00493 03194 003C19 04049(3) -006711(14) 000779(17) 00271(6)

H19A 04359 -00346 00423 0033H19B 04065 -00545 -00424 0033C20 02555(3) 018113(15) 045266(18) 00300(7)

H20A 03249 01899 044 0036H20B 02733 01608 05011 0036C21 02566(3) -002023(14) 033016(16) 00241(6)

H21A 03055 -00026 03026 0029H21B 02111 -00503 02977 0029


Spacing purpose

62


H22A 05503 0156 00069 0031H22B 05277 01384 -00785 0031C23 08001(3) 029944(14) 056911(16) 00243(6)

H23A 07195 03026 05566 0029H23B 08314 03371 05926 0029C24 11024(2) 004903(15) 027077(16) 00248(6)

H24A 10572 00145 02489 003H24B 10525 00797 02811 003C25 07036(3) 036725(14) 042883(17) 00264(6)

H25A 06953 03997 03923 0032H25B 06985 0385 0476 0032C26 06671(3) -018783(13) 013254(15) 00244(6)

H26A 07249 -0218 01498 0029H26B 0596 -02086 01219 0029C27 10680(3) 009479(19) 014209(19) 00405(9)

H27A 11036 0103 01021 0049H27B 10158 00618 01255 0049C28 08147(3) -013913(15) 060667(18) 00295(7)

H28A 08816 -01277 05922 0035H28B 0837 -01602 06545 0035C29 11574(3) 007416(17) 021252(18) 00324(7)

H29A 12038 00432 01987 0039H29B 12045 01082 02336 0039C30 04971(3) 034978(17) 04101(2) 00378(8)

H30A 0441 03181 04007 0045H30B 05071 03636 04614 0045C31 06073(3) 032287(16) 040217(19) 00327(7)

H31A 06232 02859 04315 0039H31B 06001 03126 03499 0039C32 06722(3) -014281(14) 019599(16) 00283(7)

H32A 06229 -0109 01771 0034H32B 07473 -01271 02135 0034





64



O4 ZR2 O107 10238O107 ZR4 O1 10278

O1 ZR4 O101 1035O101 ZR5 O2 10303

O2 ZR5 O104 10309O104 ZR3 O5 10424












Figure 5 a) and b)












66















discussed herein


68 35 Discussion

























reference























352 Mass Spectra







diffraction









MALDI first
























and 866 amu






























assigned




















353 Classification




























11 a) M6X8L6144-150




76












Scheme 2 (favored)










follows



































356 Prospects


























































were present

83

















84



























O + RO CH 16 13 -16 -22 -2 -3 -42 -22 -28 828O CH2 16 14 -10 -16 -2 -2 -36 -16 -22 834

CH O 13 16 -4 -10 -1 -2 -24 -4 -10 810CH2 O 14 16 -16 -22 -2 -2 -36 -16 -22 822


-1 -2 -24-2 -1 -30-1 -1 -18-2 -2 -36

-1 -2 -24-1 -1 -18-1 -1 -18-2 -1 -30

-2 -2 -36-2 -1 -30-1 -2 -24-2 -2 -36


L12 X6 mascharge



O + RO CH 16 13 -14 -20 -2 -3 -42 -20 -26 830O CH2 16 14 -8 -14 -2 -2 -36 -14 -20 836

CH O 13 16 -2 -8 -1 -2 -24 -2 -8 812CH2 O 14 16 -14 -20 -2 -2 -36 -14 -20 824

-1 -2 -24-2 -1 -30-1 -1 -18-2 -2 -36

-1 -2 -24-1 -1 -18-1 -1 -18-2 -1 -30

-2 -2 -36-2 -1 -30-1 -2 -24-2 -2 -36


86




principle)











































36 Conclusions






































proofreading





the manuscript












DrMallouk Lab space





appreciated

38 References


14 (2) 97-113






347 (6291) 354-358


1993 8 (8) 2054-2097







7568


Society 1996 118 (2) 446-450



1466


10903


5423


Physics 2003 118 (17) 7737-7740


2004 108 (49) 18796-18798


121 (21) 10321-10324


Chemical 2005 239 (1-2) 116-124


119 (32) 7417-7422


19211-19214


Science 1993 260 (5105) 195-196


1994 13 (8) 1197-1223


186


2) 1-78






9122-9134




2002 6 (4) 337-345


(5056) 515-516


104 (9) 3893-3946




Edition 1999 38 (21) 3165-3168








Elsevier 1994


1531-1532




8469




107 (15) 4571-4573


109 (16) 4844-4850


2) 21-34


67





575-587





(16) 4618-4619


(8) 1927-1934

57 Smith J D C J D JACS 1985 107 (5704)


312





2171-2177









Compounds 1998 278 (1-2) 123-129



domain In






1991 598 (7-8) 363-370


619




553-556





(12) 1777-1779




527


Society 1998 120 (44) 11391-11400


116 (17) 7909-7910



Chemie 1996 622 (3) 425-431






2988-2994


(1-2) 239-250


4047-4054








1996-2003





2006 18 10521


Freeman 2005


Polyhedron 1999 18 (6) 787-792




17-21









(1-3) 181-187





Spectrometry 2007 265 (1) 15-22







Co KGaA 2007



(12) 1088






379








Science 1978 34 (JUN) 1764-1770


2963-2968




(3589)



(26) 10944





477


Transactions 1999 (8) 1301-1305


1-7








4532-4535




Chemistry 1970 9 (6) 134





2002 (5) 1198-1202




1986 108 (9) 2474-2476


2003 22 (12) 1553-1559





(2) 285-295













2019



114 (15) 6152-6158


Spectrometry 1992 3 (4) 464-466




271


312








(19) 627-627




single bond In 2008


2541-2550





Chemistry 1984 56 (1) 25-33


Society 1978 100 (11) 3611-3613



565




(20) 1995-1996




2006 632 (12-13) 1956-1958


3498-3512

103 Chapter 4



41 Abstract















104 42 Introduction













materials













(vide infra)












































43 Experimental









108













well


















V35




















433 Calculation










discussion is given

112 44 Results
























b) Equation 4-1


(3421 mz)





















































h

a) 15 mont













of trideagold







119


Au11 series

eds

Au13 series

Au12 series


120

Clusters+ Mass (mz)

Oxygen Adduction







Au13(depp)Cl4(PPh3)3(P1)3 3974 1 8e 1212


121




MassLynx 3 080

Figure 4-5b

Figure 4-5c

(3117mz) [Au12(depp)4Cl3]+

(depp) Cl ]3 4 4+ (3583 mz) and





443 31P-NMR








123








ratio)






















[P1(1+2+3) ] [PPh3(1+2+3)] = 43 1











444 TEM


























127


Spacing purpose

128






are shown below
























45 Discussion














































etc40




















































from Au9+ to Au13

















137















MPCs is made here












raised24 67


















phase































section)








[Pd561(phen)60](OAc)18099





















143 46 Future Work















halide anions45

47 Conclusions

















48 Acknowledgements



















4-9 References





9266-9272








W Du K Du A 2007


Lizishu 2006 (18(9)) 1515-1518



4943










Society 2006 128 (1) 257-264





2006



14627


7493







(14) 4046-4047


8126


23 (4) 2247-2254







Sciences 2001 56 (8) 728-734





Chemistry B 2006 110 (43) 21416-21418




121 (4) 882-883




(51) 15742-15743














(5) 561-566


1994 33 (2) 207-209


ASAP




Science 2007 318 (5849) 430-433


Society 1997 119 (39) 9175-9178










1989 246 (4926) 64-71






1995 231 (1-2) 65-71




(23) 8195-8201




















325










2008


Chemistry B 2006 110 (24) 11611-11614








2004




2000 33 (3) 657-659












(13) 1163-1169




11600











999


2002 106 (39) 9979-9981









428


304 (5667) 84-87


1413

153

Chapter 5

Conclusion Remarks







learning































155 References











156

Appendix A












this Appendix














purpose













stated the paradox

158










159









160

100nm

100nm


100nm

161


















162


Zr 3d25

ZrO2 3d52

ZrO2 3d32

ZrC 3d 32

Zr() 3d52

Zr() 3d32

Zr() 3d32

Zrdeg 3d52

Zrdeg 3d52

Zrdeg 3d32


Zrdeg 3d32

Pos1820918450180531829417855180961766717907

Area297441982422114147325452363427011799

Zr 3

d

x 102

6

8

10

12

14

16

18

20

22

24

26

CPS









costly

















164


20nm






165



NOVA (problem)


Improvement





higher cluster flux




control no gas)


gas matrix









property No




166




A5 Acknowledgements





A6 References




and Technology 2000 8 (1-2) 27-38


Science 1993 260 (5105) 195-196


156


8579-8587








colleague In 2005





(15) 3497-3511



1997 119 (32) 7417-7422




2005 123 (15)


1992 256 (5058) 818-820


13-21





PA 2006

169

Appendix B












NMR (Figure B5-B8)








































following equation







175




Oxidation induced

middotP2 + middotP1


[Au13(depp)3(P1)(

[Au13(depp)2(P1)2(P

[Au13(depp)(P1)3(P


3[Au13(depp)4

[Au13(depp)4

















listed below

177 Electron


2 O2

3 O3

4 O4

3351 1 O

2 O2

O3

1O4

1 1






2 6O2





3583 1 O

2 O2

3 O3

4 O4

1 4O


4 O45 O5

6 O6




9 O9


6 O6



3 O3

4 O45 3 3963 3965 Au13Cl5P11C56H134 Π Fig4-6 c

Au13 13 6 3 3986 3988 Au13Cl3P12C66H1565 O5

radic Fig4-6 c

Electron



elimi 13 3 1 4 3 1 3990 3992

3583plus O

plus O

plus O



simulations



179 Spacing Purpose



f) 3714 mz


180



i) 3987 mz


181










behaviors11




182























183 B7 References




Chemistry B 2006 110 (43) 21416-21418


Chemistry B 2002 106 (39) 9979-9981











KGaA Weinheim 2004



14664-14669






(1) 993-999






237-325


165





185 Appendix C



Low M

ass Limit (m

z) 8041


Hershey PA

VITA

Lin Gao


Academia





Abstract



12 Motivation


14 References


21 Abstract

22 Introduction

23 Experimental

24 Results

25 Discussion

26 Conclusion

27 Acknowledgements

28 References


31 Abstract

32 Introduction

33 Experimental






34 Results




3431 By-products



35 Discussion


352 Mass Spectra

353 Classification



356 Prospects



36 Conclusions

37 Acknowledgements

38 References

41 Abstract

42 Introduction

43 Experimental



433 Calculation

44 Results



443 31P-NMR

444 TEM

45 Discussion






46 Future Work

47 Conclusions

48 Acknowledgements

4-9 References

Chapter 5

Conclusion Remarks

References

Appendix A






A5 Acknowledgements

A6 References

Appendix B







B7 References

Appendix C
