A new generation of Titanium based catalysts for ethylene polymerization has been developed through the Surface Organometallic Chemistry (SOMC) methodology using a novel type of silica support having a 3D fibrous morphology, KCC-1. The first type of Tibased catalyst was obtained by reacting isolated silanol surface groups, ≡SiOH of KCC-1 (dehydroxylated at 700 ⁰C under high vacuum, 10-5 bar) with titanium (IV) tetraneopentyl, Ti(CH2tBu)4 to produce [(≡SiO)Ti(CH2tBu)3]. The second type of Ti-based catalyst was generated by using an Al-modified KCC-1. The peculiarity of this support is due to the presence of tetra-coordinated aluminum-bound hydroxyl group, [(≡Si-O-Si≡)(≡SiO)2Al- OH] that can be used as a Lewis Acid anchor sites and generate new catalytic properties. The well-defined [(≡Si-O-Si≡)(≡SiO)2Al-OH] was obtained by reacting diisopropylaluminum hydride with KCC treated at 700 °C followed by a thermal treatment at 400 °C and oxidation with N2O. IR spectra of pyridine adsorbed on the Al sites show that these were strong Lewis acid sites (constituting 80% of the total Al sites). Thus, the highly electrophilic support surface was used to create a single well-defined surface organo-titanium fragment [(≡Si–O–Si≡)(≡Si–O–)2Al–O–Ti(CH2tBu)3] by the reaction of the surface [(≡Si–O–Si≡)(≡Si–O)2Al–OH]) groups with Ti(CH2-tBu)4 at room temperature for 4 h in dry pentane. The performance of each Ti-supported catalyst assessed for ethylene polymerization. It was found that Al-modified support (highly electrophilic) provide better activity compared to the unmodified one. Indeed, the productivity of the catalyst [(≡Si–O– Si≡)(≡Si–O–)2Al–O–Ti(CH2tBu)3] was found to be 67.8 g of PE/ 1mmol Ti/ 1h with molecular weight of 3208408 g/mol; polydispersity was found to be 2.3, and (HDPE) high-density polyethylene was obtained. In contrast, [(≡SiO)Ti(CH2tBu)3] (unmodified one) produces lower molecular weight polymer 989843 g/mol, higher polydispersity (PD) 6.7 and low-density polyethylene (LDPE) productivity was found to be 14.670 g PE/1mmol Ti /1h. These results demonstrate that modification of the oxide ligands on silica through a generation of Al Lewis acid site opens up new catalytic properties, markedly enhancing the catalytic performance of supported organotitanium species. We also demonstrate how the silica mesostructure (2D vs 3D ) affects the catalytic activity in ethylene polymerization. While SBA15 (2D) could limit the accessibility of the active sites resulting in lower yield. In contrast, KCC-1 (3D) are more active in ethylene polymerization, because the active sites reside on the external surface are fully accessible to the substrate.

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.

Over the past decades, since the discovery of a single–site silica-supported catalyst for the alkane metathesis reaction by our group, we have been extensively working on the development of supported catalytic systems for the improved alkane metathesis reaction. During these developments, we understand the reaction mechanism and reached a new perspective for the synthesis of various supported bimetallic systems via the surface organometallic chemistry (SOMC) approach. Recently, with this bi-metallic system, we got a very high TON (10000) in propane metathesis reaction. As these catalysts are very efficient for linear alkanes we thought to apply it for cyclo-alkanes specifically, for cyclo-octane metathesis expecting better activity. Besides, the value of the ring alkanes are higher than the linear alkanes. The current work demonstrates a combination of [(ΞSi−O−)W(Me)5] and [(ΞSi− O−)Ti(Np)3 pre-catalyst with several supports (SiO2-700, SBA-15 and MCM-41) for metathesis of cyclooctane. The catalysts have been synthesized and fully characterized by elemental analysis (EA), FT-IR and NMR spectroscopies. After fully characterization the bi-metallic catalyst was tested for metathesis of cyclooctane with highest ever TON 2500 as compared to that of mono-metallic catalyst where we got 430 TON. Which again corroborates our prediction that bimetallic catalysts are better catalysts than monometallic catalysts.

Nous avons fait l'analyse des flux cytométrie nous a permis d'évaluer les changements dans le nombre de cellules de Sertoli et germinales par le cadmium. Seulement cellules germinales ont diminué dans le temps et de manière dose-dépendante. CS fragmenté, asynapsis et "mitée" CS ont été observés. Cd induit modifications ex-vivo en cours de la méiose. BPA changé chronologie de la méiose et active le point de contrôle de pachytène. Asynapsis et la fragmentation ont été induites. Noyaux leptotène anormaux, et zygotène asynapsed, observées. CS pulvérisé indiqué les anomalies de recombinaison et / ou d'appariement génétique.BPA modifie principales fonctions biologiques et les voies canoniques. Le nombre de gènes affectés par BPA a augmenté au cours du temps d'exposition. Changement Fold augmenté. Quatre fonctions altérées étaient le cancer, la mort cellulaire, le développement cellulaire et la cellule de cellulaire signalisation. Nous insistons sur le fait que les gènes liés à l'ADN interagi ORD réparation perturbés.la mesure des métaux dans le plasma séminal et de l'ADN du sperme des hommes normaux et anormaux. Nous avons utilisé ICP / MS pour mesurer la concentration de métal dans l'ADN de le sperme et plasma séminal. Tous les métaux analysés ont été détectés dans le plasma séminal. De l'ADN de sperme, As, Hg, Sb et Se, ont été non détecté par cette méthode. Aucune correlation des concentrations de métaux entre le plasma séminal et d'ADN de sperme ont été observées. Les concentrations de métaux, dans le sperme normaux et anormaux, visualiser une augmentation significative de Sb dans le plasma séminal et de Al dans l'ADN des spermatozoïdes dans le sperme de groupe anormal. / We did Flow cytometric analysis enabled us to evaluate changes in the number of Sertoli cells and germ cells by cadmium. Only germ cells were decreased in a time and dose dependent manner. Fragmented SC, asynapsis and "motheaten" SC were observed. Cd induced ex-vivo modifications in meiotic process. BPA changed meiotic chronology and activates the pachytene checkpoint. Asynapsis and fragmentation were induced. Abnormal leptotene nuclei, and asynapsed zygotene, observed. Pulverized SC indicated the abnormalities of genetic recombination and/or pairing. Transcriptomic analysis showed that BPA alters main biological functions and canonical pathways. The number of genes affected by BPA increased over the exposure time. Fold change increased. Four impaired functions were cancer, cell death, cellular development and cell to cell signaling. We emphasize that interacted genes linked to DNA DSB repair disturbed.The other part of this thesis is including the measurement of metals in seminal plasma and in sperm DNA of normal and abnormal men. We used ICP/MS to measure the metal concentration in the seminal plasma and sperm DNA. All metals analyzed were detected in seminal plasma. In sperm DNA, As, Hg, Sb and Se, were undetected with this method. No correlation between the seminal plasma and sperm DNA metal concentrations were observed. The metal concentrations, in normal and abnormal semen, visualized a significant increase of Sb in the seminal plasma and of Al in the sperm DNA in the abnormal semen group.