Surface Organometallic Chemistry leads to the combination of the high activity and specificity of homogeneous catalysts with the recoverability and practicality of heterogeneous catalysts. Most metal complexes used in this chemistry are grafted on metal oxide supports such as amorphous silica (SiO2) and γ-alumina (Al2O3). In this thesis, we sought to enable the use of titania (TiO2) as a new support for single-site well-defined grafting of metal complexes. This was achieved by synthesizing a special type of anatase-TiO2, bearing a high density of identical hydroxyl groups, through hydrothermal synthesis then post-treatment under high vacuum followed by oxygen flow, and characterized by several analytical techniques including X-ray diffraction, transmission electron microscopy, infrared spectroscopy and nuclear magnetic resonance. Finally, as a proof of concept, the grafting of vanadium oxychloride (VOCl3) was successfully attempted.

The main target of this thesis is the design of a new aluminum-based surface ligand with low coordination and expected high acidity. These new supports will serve for the immobilization of different organometallic complexes with the surface organometallic chemistry (SOMC). The resulting molecular like species will be used for various catalytic applications including alkane metathesis, olefin metathesis and polymerization. The first chapter is an introduction to the field of catalysis, more specifically, surface organometallic with a summary of its concept and the main examples cited for the immobilization of transition metal complexes on different oxide surfaces (silica, silica-alumina and alumina). This chapter presents, as well, an overview of the use of the aluminum alkyls compounds and their immobilization on a surface for the generation of various aluminum based surfaces. The Second chapter details the reaction involving the grafting of the monomeric triisobutylaluminum on SBA-15700. The final structures and the mechanism involved were determined by various characterization techniques including FT-IR, 1H and 13C solid-state NMR, and DFT calculations. The reaction leads mainly to a bipodal [(≡Si-O-Si≡)(≡SiO)2AliBu] species with 3 differents types of alumium coordinations (AlIV, AlV and AlVI) along with 37% [≡Si-H] and 63% [≡Si-ibu]. The Third chapter describes the reaction of a highly dehydroxylated SBA-15 with a trimeric di-isobutyl aluminum hydride, [i-Bu2AlH]3 is investigated by both experiments and DFT calculations. The mechanism involves very different pathway comparing to the TIBA case where only AlIV-isobutyl were generated. Further β-H elimination leads to an well-defined AlIV hydride analog [(≡Si-O-Si≡)(≡SiO)2Al-H]. The later shows good activity in ethylene polymerization reaction with the formation of HDPE. The Fourth Chapter deals with the immobilization of the 2nd generation Hoveyda-Grubbs (HGII) catalyst onto well-ordered 2D hexagonal (SBA15), and 3D fibrous (KCC-1) mesostructure silica containing tetra-coordinated [Al-H] sites. The resulting catalysts show high activity in the non-functionalized olefin metathesis of propene. The results clarified that the supported catalyst prepared using KCC-1 shows better performance than the one prepared using SBA-15 due to the diffusion effect; and exhibits much higher activity than the HG-II itself, in homogeneous phase. The Fifth chapter of this thesis presents the formation of tetra-coordinated [(≡Si–O–Si≡)(≡Si– O)2Al–OH], through [Al-H] oxidation using N2O. The synthesis was detailed and the grafted species were fully characterized. This new site will serve as anchoring site for the immobilization of the tungsten based complexes. Its activity was evaluated in the propane metathesis reactions, where a TON of 800 was obtaine, which is the highest value obtained for a SOMC monometallic catalyst. Finally, the last chapter will present the thesis conclusion including most of the ongoing applications related to the use of those new surfaces.

This thesis shed lights on metal-nitrogen organometallic fragments supported on silica surface for catalytic applications. It Focuses on group IV and V metal transition as a well-defined single-site catalysts, specifically titanium, hafnium, and tantalum to utilize them in the development of selective heterogeneous catalysis for imine metathesis, hydroamination and hydroaminoalkylation of olefins and alkynes. Developing new metal-nitrogen containing fragments by using easily available and abundant precursors which is silica SiO2 and metal amides complexes. Here, we describe metal fragments starting with hafnium-nitrogen fragment. All the catalysts were prepared by reacting homoleptic metal amido of group IV and V with partially dehydroxylated silica. In most cases the resulting surface amido is monopodal and leads to well defined single site catalysts precursors. In particular with Hf we have isolated hafniaaziridine 2.1 [(≡Si-O-)Hf(η2-MeNCH2)(η1-NMe2)(η1-HNMe2)], imido, and amido fragments 2.3 [(≡Si-O-)Hf(=NMe)(η1-NMe2)], and two intermediates the five-membered ring 2.2 [≡Si-O-Hf(HNMe2)(η2-NMeCH2CH(C6H13)CH2)(NMe2)] and 2.4 [(≡Si-O-)Hf(=NCH2Ar) (η1-NMe2)]. For tantalum 3.1 [(≡Si-O-)Ta=NtBu)(η1-NMeEt)2]; we have isolated two intermediates after treating 3.1 catalyst with aniline substrate lead to isolating 3.3 [(≡Si-O-)Ta(η1σ-NEtMe)2(η1σ-NHtBu)(NHC6H10)], and upon treating with 1-octyne lead to isolating 3.2 [(≡Si-O-)Ta(η1σ-NEtMe)2(η2-NtBuC=CC7H13)]. For titanium-nitrogen fragments, we isolated on silica SiO2-200 4.1 [(≡Si-O2-)Ti(NMe2)2 (η1-HNMe2)] and on SiO2-700 the titaniaaziridine 4.2a [≡Si-O-Ti(NMe2)3] 4.2b, [(≡Si-O-)Ti(η2-MeNCH2)(η1-NMe2)(η1-HNMe2)], the imido, and amido fragments 4.4 [(≡Si-O-)Ti(=NMe)(η1-NMe2)], and the five-membered ring intermediate 4.3 [≡Si-O-Ti(HNMe2)(η2-NMeCH2CH(C6H13)CH2)(NMe2)]. Research in this area has led to isolating several intermediates containing nitrogen fragments, this is the strength of surface organometallic chemistry which allows a deeper understanding of catalytic phenomena which could not be approached either in homogeneous catalysis or in classical heterogeneous catalysis. A molecular level characterization of the surface nitrogen containing fragments have been characterized by SOMC tools such as FTIR and EXAFS spectroscopy, elemental analysis, solid-state single and multiple quantum NMR, advanced DNP-SENS and DFT. A catalytic cycle was proposed based not only on the isolation of intermediates but also based on DFT calculations.

A specific allotrope of titanium dioxide (anatase) was synthesized with a highly anisotropic morphology ({001}-anatase) dominated by the {001} facet (81%). its surface chemistry after dehydroxylation was studied by 1H NMR and FT-IR. Influence of surface fluorides on surface chemistry was also studied by 1H NMR, FT-IR and DFT. Full attribution of the IR and NMR spectra of anatase with dominant {001} facets could be provided based on experimental data and further confirmed by DFT. Our results showed that chemisorbed H2O are still present on anatase after dehydroxylation at 350°C, and that the type of surface hydroxyls present on the {001} facet is dependent on the presence of fluorides. They also provided general insight on the nature of surface species on both fluorinated and fluorine-free anatase. The use of vanadium oxychloride (VOCl3) allowed determining the accessibility of the various OH groups spectroscopically observed. A platinum complex, (CH3)2Pt(COD), is then grafted via surface organometallic chemistry (SOMC) on morphology-controlled Anatase TiO2 to generate single, isolated Pt atoms on TiO2 nano-platelets. The resulting material is characterized by FT-IR, High resolution scanning transmission electron microscopy (HRSTEM), NMR, and XAS, and then used to perform photocatalytic water splitting. The photocatalyst with SOMC-grafted Pt shows superior performance in photocatalytic hydrogen evolution and strongly suppresses backwards reaction of H2 and O2 forming H2O under dark conditions, compared to photocatalyst prepared by standard wet impregnation at the same Pt loading. However, single Pt atoms on this surface also rapidly coalesce into nanoparticles under photocatalytic conditions. It was also found that adsorbtion of carbon monoxide gas at room temperature also triggers the aggregation of Pt single atoms into nanoparticles. A detailed mechanism is investigated for the mobility of Pt in the formation of its carbonyls using density functional theory (DFT) calculations.

La chimie organométallique de surface (COMS) est une technique utilisée pour concevoir des catalyseurs structurellement bien définis. Elle a été employée ici pour établir les fondements de la COMS sur des supports photoactifs. L’oxyde de titane, TiO2 à savoir l’anatase a été utilisé comme support photo-catalytique en raison de sa haute stabilité, photo-activité and non toxicité. La nature chimique et la densité des sites réactifs de surface ont été établies. Un complexe de Ta bien connu de la littérature a été utilisé pour mener les premières études d’interaction entre la surface et le complexe organométallique. Les résultats ont permis d’observer le greffage organométallique couplé à des mécanismes transfert de charge métal sur métal, en route vers des photo-catalyseurs bien définis / Surface organometallic chemistry (SOMC) is used to design well-defined catalysts. It has been employed here to lay the foundation of SOMC on photocatalytic support, a previously little if any explored area. TiO2 anatase was used as the photocatalytic support due to its high stability, photoactivity and nontoxicity. The chemical nature and the surface density of the reactive moieties found on anatase support has been determined. A Ta complex, well-known in literature, was used to conduct the first principal studies regarding the interaction between the surface and the organometallic complex. The results provide solid insights into organometallic grafting and metal to metal charge transfer mechanisms for developing well-defined photocatalysts by SOMC

The general objective of this thesis is the analysis of selective reactions for group VI grafted metal complexes via methods and principles of SOMC. For this objective, three approaches have been chosen. The first chapter is an introduction to the topic of selectivity in catalysis, emphasizing heterogeneous catalysis and more specifically the different approaches to support catalysts on surfaces. The concept of catalysis by design is introduced as a new way to use the surface as a ligand. Chapter 2 presents the results of a library of well-defined catalysts of group VI with identical catalytic functionality, but different ligand environment. The results reveal, that metal-carbynes are able to switch their catalytic reactivity based on the substrate that they are contacted with. The difference in reaction mechanisms and the differing reactivities towards the substrates are presented. It can be concluded that the classical ROMP is selectively achieved with cyclic alkene substrates leading to polymers whereas cyclic alkanes yield exclusively higher and lower homologues of the substrate without polymeric products. Chapter 3 presents the study of olefin metathesis of cis-2-pentene with metal-carbynes of group VI, where the selectivity of the catalyst library towards yield of cis-/trans products is analyzed. It is presented, that the ligand environment of the catalysts is showing an influence in the selectivity. Rates of cis/trans isomerization of the products are high and are approaching thermodynamic equilibrium at high conversion. Product isomerization, thermodynamic equilibrium and reactivity differences between liquid phase and gas phase products are analyzed. Chapter 4 presents the full characterization of tungsten-hydrides by selective transformation into tungsten-hydroxides. These newly discovered well-defined tungstenhydroxides are fully characterized by ICP, TEM, DRIFT, double quantum and triple quantum solid-state NMR. The presented results allow to predict that tungsten-hydrides on KCC-1700 are present as two distinct species. Catalysis results with cyclooctane show, that due to burial of the complexes in the KCC-1700 surface the tungsten-hydrides are less active towards cyclic alkane metathesis reactions with bulky cyclooctane than the metalcarbyne complexes. Chapter 5 is giving a conclusion of results and an outlook for catalytic applications of the generated tungsten-hydroxides of chapter 4.

Résumé confidentiel / Résumé confidentiel

The Minnesota Multiphasic Personality Inventory-2 (MMPI-2) is a popular measure of psychosocial functioning and psychopathology in the assessment of individuals in a variety of settings. However, the method of construction employed with the MMPI more than 60 years ago with psychiatric patients challenges the applicability of the scales for determining the psychosocial functioning of individuals from different settings. The restandardisation conducted in 1987 made no effort to eradicate the item overlap that was a result of the criterion keying method with contrasted groups. Although restandardized and updated with more contemporary language and content, the original psychiatric constructs were retained in order to maintain continuity with its predecessor. The aims of this investigation were to develop a new structure for the MMPI-2 constructed at the item-level, empirically derived and which specifically represents the dimensions that are relevant and appropriate in evaluating the psychosocial functioning of personal injury claimants. This task included comparisons with a comparable scale-level analysis and developing optimal scoring strategies where items in components and facets are allocated weightings based upon their strength of association. Study 1 was conducted using a sample of 2989 personal injury claimants assessed in Australia and the United States of America. The final sample of 3230, included 241 normal individuals, was utilized to develop a scale-level structure from 79 standard MMPI-2 scales and subscales. A nine-component solution consisting of General Maladjustment /Emotional Distress, Asocial Beliefs, Social Vulnerability, Somatic Complaints, Psychological Disturbance, Impulsive Expression, Antisocial Practices, Stereotypic Fears and Family Difficulties was derived using principal component analysis. However, intercorrelation between components in the structure signaled the need to develop a structure that would eradicate problems that were perpetuated by item overlap. The second study was conducted with a set of best practice procedures with the same clinical sample of 2989 personal injury claimants as Study 1. Forty-one components were derived through principal component analysis. Through the application of a set of criteria, a 35-component solution was retained. The pattern coefficients from the allocation of items to components determined the weightings to be applied to each item. Further analysis of the 35 components derived a substructure of 37 facets. The 35 components included only 442 of the 567 items, with the reliability coefficients of the first 25 components that ranged between .5 and .97, and the remaining 10 components that ranged from .29 to .49. The latter unreliable components were not included in the final Structural Summary, leaving 25 components (400 items) and their 33 facets for interpretation. Hence, in demonstrating the utility of the newly-derived structure, only 25 components and their 33 facets were interpreted. The 25 components were grouped conceptually into six domains. In the emotional domain were Psychological Distress (PsyDist), Anger, Fears, Psychotic Symptoms (PsyS), Paranoia (Par), Irritability (Irrit), Elation (Elat), Fear of the Dark (FD), and Financial Worry (FinWo). Somatic Complaints (SomC), Sexual Concerns (SexCon), and Gastrointestinal Problems (GasP) made up the measures in the physiological domain. In the behavioural domain were Cognitive Difficulties (CogDiff), Stimulus-Seeking (StimuS), Discipline (Dis), and Delinquency (Del) whilst the interpersonal domain was formed by Social Withdrawal (SoW), Negative Interpersonal Attitude (NIA), Timidity (Tim), Lie, Dissatisfaction with Self (DWS) and Family Relationship Difficulties (FReD). Alcoholism (Alco) was the only measure in the substance abuse domain, and the gender domain was comprised of Masculinity (Mas) and Femininity (Fem). The third study established preliminary normative means and standard deviations using a small opportunistic Australian university student sample (N = 219). No substantial gender differences were found but gender norms were maintained to facilitate comparisons with the traditional MMPI-2 approach. Comparisons of frequency of 'true' item response between the Australian university student sample and the U.S. restandardisation sample found relatively little differences and permitted evaluation of between sample differences on components and facets. The utility of the structure was demonstrated with the illustration of two clinical case examples, and a comparison was made with the standard MMPI-2 scales and subscales. The Structural Summary for the MMPI-2 demonstrated discriminative measures of psychosocial functioning that were a result of no item overlap, and the ability to attend to the different levels of intensity of self-report items because of differential weightings.