Les dendrimères et polymères contenant des métaux de transition comme le fer, lecobalt et le rhodium peuvent servir à la fabrication des nanomatériaux utiles à lacatalyse, la reconnaissance moléculaire et l’électronique moléculaire. Pour leurconstruction, des liaisons ioniques, de la chimie click : CuAAC et hydroamination, lapolymérisation ROMP et la polymérisation radicalaire ont été utilisés et ont permis laformation de nouveaux types de polyélectrolytes metallocéniques. La synthèse denouvelles nanoparticules d’or, d’argent et de palladium à partir de cesmétallopolymères et métallodendrimères ont été mises au point, conduisant à desréseaux à architecture spécifique bien définie. Ces assemblages supramoléculaireset ingénierie moléculaire ouvrent la voie vers l’application de la chimieorganométallique dans la conception de nouveaux nanomatériaux nanoparticulairesstructurés à l’aide des propriétés rédox des métallomacromolécules. / Dendrimers and polymers containing transition metals such as iron, cobalt andrhodium can serve in the fabrication of useful nanomaterials for catalysis, molecularrecognition and molecular electronics. For their construction, ionic bonds, clickchemistry: CuAAC and hydroamination, ROMP and radical polymerization were usedand allowed the formation of new types of metallocenyl polyélectrolytes. Thesynthesis of new gold, silver and palladium nanoparticles from these metallopolymersand metallodendrimers has been developed, leading to specific and well-definedarchitectures. These supramolecular assemblies and molecular engineering opensthe way towards the application of organometallic chemistry in the design of newstructured nanoparticle-containing nanomaterials using the redox properties ofmetallomacromolecules.

This thesis presents a compilation of recent work on benchmarking, applying, and developing Auxiliary Field Quantum Monte Carlo (AFQMC) for use in ab initio simulations of the electronic structure of molecules. With Chapter 1 I begin with a benchmark of phaseless AFQMC versus experiment in obtaining gas phase ligand dissociation energies of a set of tetrahedral and octahedral transition metal complexes. ph-AFQMC is shown to acquire chemical accuracy through the use of correlated sampling (CS) and CASSCF trial wave functions selected via a black box procedure. This is followed in Chapter 2 with another gas phase benchmark of ph-AFQMC versus experiment, this time calculating the redox potentials for a set of metallocenes, where we find a mix of correlated sampling and large CASSCF trials necessary to reproduce gas phase experimental values to within 1.7 ± 1.0 kcal/mol. Additionally, the inclusion of QZ ph-AFQMC values, either using UHF or CASSCF trials, was found to be necessary for a few systems, as opposed to using a hybrid approach with alternate methods such as coupled cluster to extrapolate to the basis set limit. In Chapter 3, having established protocols to obtain decent results on transition metal complexes with known experimental values, I apply ph-AFQMC to successfully predict the activity of a set of new annihilators for optical upconversion. For a set of functionalized anthracene molecules, I report agreement within statistics between ph-AFQMC and a localized approximation to coupled cluster singles doubles and perturbative triples (DLPNO-CCSD(T0)), and develop intuitive guidelines for tuning the excited state energies of anthracene. For a single molecule in an additional set of functionalized benzothiadiazole (BTD) molecules, Ph-BTD, ph-AFQMC and DLPNO-CCSD(T) disagree significantly; subsequent experimental testing validates the ph-AFQMC result. In Chapter 4 I present an approach based on localized orbitals to reduce the scaling with system size from quartic to cubic for the energy evaluation, the functional bottleneck for the majority of AFQMC calculations. Additionally, I describe the practical implementation of such an algorithm to be run on large GPU clusters. This allows AFQMC to be run for both larger systems and trials at a significantly decreased cost, while still reproducing full AFQMC results within the statistics of the method. With Chapter 5, I conclude with the development and characterization of a novel constraint, linecut (lc-) AFQMC, which exhbits distinct behavior versus the phaseless constraint. We demonstrate benchmarks for a variety of weakly to strongly correlated molecules for which we have the exact total energies, and observe that lc-AFQMC outperforms ph-AFQMC for the majority of systems studied. I conclude with the description of a systematic method to remove the linecut constraint, partially removing the bias and re-introducing the fermionic sign problem while still maintaining a practicable signal to noise ratio. This allows for us to recover the exact energy of FeO with a fraction of the cost of converging the trial wave function within ph-AFQMC.

This thesis describes the synthesis and characterisation of new mononuclear and binuclear zirconium and hafnium compounds containing ansa-bridged ligands. Some olefin polymerization studies, employing the new compounds as catalysts, are also presented. <strong>Chapter 1</strong> begins with an introduction to Ziegler-Natta polymerization of olefins, concentrating on recently developed metallocene-based catalyst systems. The second part of the Chapter charts the development of group 4 ansa-metallocene derivatives, especially their use as stereospecific catalysts. Finally, a review of binuciear group 4 metallocene compounds containing bridging bis(cyclopentadienyl)-type ligands is presented. <strong>Chapter 2</strong> describes the synthesis and characterisation of some novel mononuclear metallocene compounds of zirconium and hafnium containing ansa-bridged ligands. The ansa-bridged mononuclear compounds [{Me₂C(η⁵-C₅H₄)(η²-C₉H₆)}M(η⁵C₅H₅)Cl] (M = Zr, Hf), [{(CH₂)₅C(η⁵-C₅H₄)(η²-C₉H₆)}M(η⁵-C₅H₅)Cl] (M = Zr, Hf) and [{Me₂(η⁵-C₅H₄)(η³-C₁₃H₈)}Zr(η⁵-C₅H₅)Cl] are described, along with the X-ray crystal structures of the zirconium compounds. The η²-indenyl and η³-fluorenyl coordination modes observed for these compounds are unprecedented. The synthesis and characterisation of the novel, mononuclear ansa-bridged compounds [{Me₂C(η⁵-C₅H₄)<sub<2</sub>}M(η⁵-C₅H₅)Cl] (M = Zr, Hf) is also described, along with their X-ray crystal structures. The variable temperature solid state ¹³C CP/MAS NMR spectra of [{Me₂C(η⁵-C₅H₄)<sub<2</sub>}M(η⁵-C₅H₅)Cl] (M = Zr, Hf) show slow rotation of the C₅H₅ ring on the NMR timescale. <strong>Chapter 3</strong> describes the synthesis and characterisation of some novel homo- and hetero-binuclear metallocene compounds of zirconium and hafnium in which the metals are bridged by an unsymmetrical ansa ligand. The novel, chiral homobinuclear compounds [(η⁵-C₅H₅)MCl₂{(η⁵-C₅H₄)CMe₂(η⁵-C₉H₆)}MCl₂(η⁵-C₅H₅)] (M = Zr, Hf) are described. The ansa-bridged mononuclear compounds [{Me₂C(η⁵-C₅H₄)(η²-C₉H₇)M(η⁵-C₅H₅)Cl] (M = Zr, Hf) are used as reagents for the selective synthesis of the heterobinuclear analogues [(η⁵-C₅H₅)MCl₂{(η⁵-C₅H₄)CMe₂(η⁵-C₉H₆)}M*Cl₂(η⁵-C₅H₅)] (M = Zr, M* = Hf ; M = Hf, M* = Zr) and the unsymmetrical homobinuclear compound [(η⁵-C₅H₅)ZrCl₂{(η⁵-C₅H₄)CMe₂(��⁵-C₉H₆)}ZrCl₂(η⁵-C₅Me₅)]. The methylated derivatives [(η⁵-C₅H₅)M(CH₃)₂{(η⁵-C₅H₄)CMe₂(η⁵-C₅H₆)}M*(CH₃)₂(η⁵-C₅H₅)] (M = Zr, M* = Zr, Hf; M = Hf, M* = Zr, Hf) are also described. The structurally related mononuclear compounds [(η⁵-C₅H₅)MCl₂{(η⁵-C₅H₄)CMe₂(C₉H₇)}] (M = Zr, Hf) and [(η⁵-C₅H₅)Zr(CH₃)₂{(η⁵-C₅H₄)CMe₂(C₉H₇)}] have also been prepared. <strong>Chapter 4</strong> presents some olefin polymerization studies using the new compounds described in Chapter 3 as catalysts, along with either methylaluminoxane or the recently developed co-catalysts [Ph₃C]⁺[B(C₆F₅)₄]^- and B(C₆F₅)₃. <strong>Chapter 5</strong> provides the experimental details for the reactions described in this thesis and the characterising data for all new compounds are given in <strong>Chapter 6</strong> Crystallographic data for the for the X-ray structure determinations in Chapter 2 are given in the <strong>Appendices</strong>.

This thesis is concerned with structure-reactivity relationships in metallocene chemistry. In particular new ansa-metallocenes of Groups 5-7 have been prepared. The structure and reactivity of these ansa-metallocenes is compared to the corresponding nonbridged metallocenes.

Thesis (Ph.D)--Chemical Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Jones, Christopher; Committee Member: Koros, William; Committee Member: Lyon, Andrew; Committee Member: Nair, Sankar; Committee Member: Weck, Marcus. Part of the SMARTech Electronic Thesis and Dissertation Collection.

In this master thesis 1,2-disubstituted cyclopentadienes were prepared by method composed of three transition metal catalysed reactions. Then, the cyclopentadienes were converted into cyclopentadienyl manganese, rhenium and iron complexes. A one-pot synthesis of the cyclopentadienyl metal complexes was developed without isolation of the intermediate cyclopentadienes. The second goal of this thesis was preparation of vinyl-substituted cyclopentadienes using ring closing enyne metathesis. The last part of thesis dealt with synthesis of a chiral cyclopentadiene and preparation of the corresponding metal complexes. The important part of this work was preparation of starting materials using palladium catalysed cross-coupling reactions. Key words: cyclopentadienes, carbometallation, cross-coupling, metathesis, metallocenes.

Les travaux présentés dans ce manuscrit portent sur la (co)polymérisation syndiosélective du styrène catalysée par des complexes de métaux du Groupe 3. La première partie est consacrée à l’optimisation des performances catalytiques de systèmes neutres de type {Cp/Flu}. Une série de précurseurs ansa-lanthanidocènes a été synthétisée et testée en homopolymérisation du styrène et en copolymérisation styrène-éthylène. Il a été montré que la nature de la substitution du motif fluorényle, la nature du centre métallique ainsi que les conditions de polymérisation ont une influence significative sur la productivité des catalyseurs. En conditions optimisées, des productivités maximales de 4,500 kg(sPS)·mol⁻¹·h⁻¹ et 5,430 kg(sPSE)·mol⁻¹·h⁻¹ ont été obtenues, démontrant la robustesse sans précédent de ces systèmes catalytiques en conditions extrêmes (Tpolym jusqu’à 140 °C et charge en monomère > 100,000). De nouveaux co- et terpolymères styrène-myrcène et styrène-myrcène-éthylène contenant des séquences de polystyrène syndiotactique ont également été synthétisés. La deuxième partie de ce travail porte sur le développement de nouveaux catalyseurs cationiques. Très peu des composés ciblés ont été isolés de par la réactivité déroutante entre les pro-ligands et les précurseurs ou la faible stabilité thermodynamique des produits. De plus, les productivités catalytiques des composés qui ont été isolés se sont avérées assez faibles. / The work presented in this thesis manuscript focuses on the syndioselective (co)polymerization of styrene catalyzed by Group 3 catalysts. The first part is dedicated to the optimization of the catalytic performances of neutral {Cp/Flu} systems. A series of new allyl ansa-lanthanidocenes was synthesized and explored in styrene and styrene-ethylene (co)polymerizations. It is shown that the substitution of the fluorenyl moiety as well as the nature of the metal center and the polymerization conditions exert a strong influence on the catalyst productivity. Under optimized conditions, maximum productivities of up to 4,500 kg(sPS)·mol⁻¹·h⁻¹ and 5,430 kg(sPSE)·mol⁻¹·h⁻¹ were achieved, highlighting the unprecedented robustness of those catalytic systems under drastic conditions (Tpolym up to 140 °C and monomer : catalyst ratios > 100,000). New styrene-myrcene(-ethylene) co- and terpolymers containing syndiotactic polystyrene sequences were also synthesized. The second part of the study was focused on the development of new cationic catalysts. Only a short series of compounds was successfully isolated among the targeted ones, because of unclear reactivity of pro-ligands and metal precursors and/or low thermodynamic stability of the products. The new isolated compounds were also used in styrene homopolymerization affording unexpectedly poor performances.

This work is divided into two parts that are focused on the synthesis and assessment of photophysical properties of two structurally related compounds: (i) 9,9'-spirobifluorenes (SBFs) and (ii) dispiroindeno[2,1-c]fluorenes (DS-IFs). (i) In the first part, a five-step synthetic approach to SBFs was developed and as the crucial step was used an intermolecular [2+2+2] cyclotrimerization of symmetrically or unsymmetrically substituted diynols with alkynes catalyzed by Rh-complexes. Catalyst screening showed that Wilkinson's catalyst (RhCl(PPh3)3) had the highest efficiency in yielding 1,2,3,4-substituted fluorenols - the key intermediates. The fluorenols were then converted into SBFs bearing various electron-donating and -withdrawing groups, aromatic substituents, and -extended aromatic hydrocarbon moieties (PAHs). Altogether 19 different SBFs were prepared and their photophysical properties screened. The fluorescent emission maxima em were in the range of 315-389 nm with excellent quantum yields s (up to 1.00). As far as the substituent effect is concerned the presence of electron-withdrawing substituents on the SBF scaffold results in the red-shift of the emission maxima. (ii) In the second part, a similar synthetic strategy was applied for synthesis DS-IFs. In this instance was utilized again the...

Two projects are presented here. In the first, metal-cyclopentadienyl bond dissociation energies (BDEs) were measured for seven metallocene ions (Cp2M+, Cp = η5-cyclopentadienyl = c-C5H5, M = Ti, V, Cr, Mn, Fe, Co, Ni) using threshold collision-induced dissociation (TCID) performed in a guided ion beam tandem mass spectrometer. For all seven room temperature metallocene ions, the dominant dissociation pathway was simple Cp loss from the metal. Traces of other fragment ions were also detected, such as C10H10+, C10H8+, C8H8+, C3H3+, H2M+, C3H3M+, C6H6M+, and C7H6M+, depending on the metal center. Statistical modeling of the Cp-loss TCID experimental data, including consideration of energy distributions, multiple collisions, and kinetic shifts, allow the extraction of 0 K [CpM+ - Cp] BDEs. These are found to be 4.95 ± 0.15, 4.02 ± 0.14, 4.22 ± 0.13, 3.51 ± 0.12, 4.26 ± 0.15, 4.57 ± 0.15, and 3.37 ± 0.12 eV for Cp2To+, Cp2V+, Cp2Cr+, Cp2Mn+, Cp2Fe+, Cp2Co+, and Cp2Ni+, respectively. The measured BDE trend is largely in line with arguments based on a simple molecular orbital picture, with the exceptions of a reversal in Cp2Mn+ and Cp2Ni+ BDEs (although within uncertainty), and the exceptional case of titanocene, most likely attributable to its bent structure. The new results presented here are compared to previous literature values and are found to provide a more complete and accurate set of thermochemical parameters. In the second project, imaging photoelectron photoion coincidence (iPEPICO) spectroscopy has been used to determine 0 K appearance energies for the unimolecular dissociation reactions of several energy selected 1-alkyl iodide cations n-CnH2n+1I+ → CnH2n+1+ + I, (n = 2-5). The 0 K appearance energies of the iodine-loss fragment ions were determined to be 9.836 ± 0.010, 9.752 ± 0.010, 9.721 ± 0.010, and 9.684 ± 0.010 eV for n-C3H7I, n-C4H9I, n-C5H11I, and n-C6H13I molecules, respectively. Isomerization of then-alkyl iodide structures into 2-iodo species adds complexity to this study. Using literature adiabatic ionization energies, ionic bond dissociation energies were calculated for the four modeled iodoalkyl cations and it was shown that as the alkyl chain length increases, the carbon-halogen bond strength decreases, supporting the suggestions set forth by inductive effects. In the modeling with statistical energy distributions and rate theory, the role of hindered rotors was also evaluated and no strong experimental evidence was found either way. The heaviest species in the series, heptyl iodide (C7H15I) was also measured via iPEPICO and showed to have a greater complexity of fragmentation than the lighter analogs. Sequential dissociation of the first fragment ion, C7H15+ leads to C4H9+, C5H11+, and C3H7+ ions in competitive dissociation processes, dominated at low energies by the C4H9+ cation.

The major goals of this thesis were to: (1) create a site-isolated aminosilica material with higher amine loadings than previously reported isolation methods, (2) use spectroscopic, reactivity, and catalytic (olefin polymerization precatalysts) probes to determine isolation of amine groups on these organic/inorganic hybrid materials, (3) synthesize an organic/inorganic hybrid material capable of activating Group 4 olefin polymerization precatalysts, and (4) synthesize a high amine loaded organic/inorganic hybrid material capable of reversibly capturing CO2 in a simulated flue gas stream. The underlying motivation of this research involved the synthesis and design of novel amine and sulfonic acid materials. Traditional routes to synthesize aminosilicas have led to the formation of a high loading of multiple types of amine sites on the silica surface. Part of this research involved the creation of a new aminosilica material via a protection/deprotection method designed to prevent multiple sites, while maintaining a relatively high loading. As a characterization technique, fluorescence spectroscopy of pyrene-based fluorophores loaded on traditional aminosilicas and site-isolated aminosilicas was used to probe the degree of site-isolation obtained with these methods. Also, this protection/deprotection method was compared to other reported isolation techniques with heterogeneous Group 4 constrained-geometry inspired catalysts (CGCs). It was determined that the degree of separation of the amine sites could be controlled with protection/deprotection methods. Furthermore, an increase in the reactivity of the amines and the catalytic activity of CGCs built off of the amines was determined for aminosilicas synthesized by a protection/deprotection method. The second part of this work involved developing organic/inorganic hybrid materials as heterogeneous Brønsted acidic cocatalysts for activation of olefin polymerization precatalysts. This was the first reported organic/inorganic hybrid sulfonic acid functionalized silica material capable of activating metallocenes for the polymerization of ethylene when small amounts of an alkylaluminum was added. Lastly, an organic/inorganic hybrid hyperbranched aminosilica material capable of capturing carbon dioxide from flue gas streams was synthesized. This material was determined to capture CO2 with capacities higher than currently reported aminosilica adsorbents.