Dissociation of gas hydrates has been the primary concern of the oil and gas industry for flow assurance, mainly in an offshore environment. There is also a growing interest in the rapid formation of gas hydrates for gas storage, transport of natural gas and carbon sequestration. In this thesis, we experimentally measure the kinetics of formation and dissociation of methane hydrates and the effect of various anionic and cationic surfactants such as sodium dodecyl sulfate (SDS), cetyl trimethylammonium bromide (CTAB) and alpha olefin sulfonate (AOS) on the association/dissociation rate constants. The importance and necessity of micelle formation in these surfactants has been studied. The effect of foam generation on the rate of formation of these hydrates has also been measured. SDS was found to significantly decrease the induction time for hydrate formation. There was an added decrease in the induction time when a foamed mixture of water and SDS was used. On the other hand CTAB and AOS had an inhibiting effect. The contribution of micelles towards promoting hydrate formation was demonstrated with a series of experiments using SDS. The micelles formed by these surfactants appear to serve as nucleation sites for the association of hydrates. New experimental data is presented to show that some surfactants and the use of foam can significantly increase the rate of hydrate formation. Other surfactants are shown to act as inhibitors. A new experimental setup is presented that allows us to distinguish between surfactants that act as promoters and inhibitors for hydrate formation. / text

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Palladium-catalyzed olefin dioxygenation is a powerful tool in the generation of complex and valuable substrates, one which may become complimentary to the well known Sharpless dihydroxylation. In this work the mechanism of this transformation is examined via reaction kinetics and Hammett studies, which corroborate a PdII/IV catalytic cycle and suggest that the rate determining step is the oxidation of PdII to PdIV. Olefin dioxygenation was also found to proceed in the presence of catalytic quantities of BF3•OEt2 or triflic acid, with stoichiometric hypervalent iodine oxidant and an acetic acid solvent. Furthermore, asymmetric variants of intramolecular palladium-catalyzed olefin dioxygenation were also investigated, which resulted in the formation of tetrahydrofuran products in up to 36% ee. Next, chelate-assisted C–H bond functionalization of indoles at the C7 position and of carbazoles at the C1 position was investigated with a variety of arylation, halogenation and oxygenation techniques. Lastly, our efforts towards the synthesis of a mono-phosphine based [5]helicene ligand via olefin metathesis and photocyclization strategies will be discussed.

Palladium-catalyzed olefin dioxygenation is a powerful tool in the generation of complex and valuable substrates, one which may become complimentary to the well known Sharpless dihydroxylation. In this work the mechanism of this transformation is examined via reaction kinetics and Hammett studies, which corroborate a PdII/IV catalytic cycle and suggest that the rate determining step is the oxidation of PdII to PdIV. Olefin dioxygenation was also found to proceed in the presence of catalytic quantities of BF3•OEt2 or triflic acid, with stoichiometric hypervalent iodine oxidant and an acetic acid solvent. Furthermore, asymmetric variants of intramolecular palladium-catalyzed olefin dioxygenation were also investigated, which resulted in the formation of tetrahydrofuran products in up to 36% ee. Next, chelate-assisted C–H bond functionalization of indoles at the C7 position and of carbazoles at the C1 position was investigated with a variety of arylation, halogenation and oxygenation techniques. Lastly, our efforts towards the synthesis of a mono-phosphine based [5]helicene ligand via olefin metathesis and photocyclization strategies will be discussed.

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.

Catalytic systems based on zirconoces which are able to polymerize ethene have been studied. Structural modifications on the basic catalytic precursor, diphenylmethylidene(η5- cyclopentadienyl)(η5-9-fluorenyl) zirconium dichloride (5a) have been carried out. The catalytic precursors 5a and bis(para-fluorophenyl)methylidene(η5-cyclopentadienyl)(η5-9- fluorenyl)zirconium dichloride (5b) were synthesized, as well the pre-ligand (1- cyclopentadienyl)(9-fluorenyl)[1,1-bis(para-methoxyphenyl)]methane (3c). Complex Ph2C(Cp)(Flu)ZrCl2 was supported on silica by two different techniques. i) directly on silica, grafting, and ii) on silica modified with MAO. Catalytic tests on homopolymerization of ethene and copolymerization of ethene/1- hexene reactions, using the catalytic precursor 5a, were carried out either on homogeneous and heterogeneous media. The polymers obtained were characterized and their properties were correlated with the reaction polymerization conditions. Three different reactors, under different reaction conditions, were employed to carried out polymerization reactions. Several analytical techniques were employed to characterize the pre-ligands, catalytic precursors, polymers, and supports obtained. / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Neste trabalho foram estudados sistemas catalíticos, a base de metalocenos de zircônio, capazes de promover reações de polimerização de eteno. Foram realizadas de modificação estrutural do precursor catalítico base, difenilmetilideno(η5-ciclopentadienil)(η5- 9-fluorenil)zircônio (5a). Os precursores catalíticos metalocênicos 5a e dicloreto de bis(parafluorofenil) metilideno(η5-ciclopentadienil)(η5-9-fluorenil)zircônio (5b) foram sintetizados, como também o pré-ligante (1-ciclopentadienil)(9-fluorenil)[1,1-bis(para-metoxifenil)] metano (3c). O complexo Ph2C(Cp)(Flu)ZrCl2 (5a) foi suportado em sílica através de duas técnicas: i) diretamente em sílica, grafting e ii) em sílica modificada por metilaluminoxano (MAO). Foram realizados testes catalíticos empregando-se o precursor catalítico 5a, tanto em meio homogêneo, quanto heterogêneo, frente a reações de homopolimerização de eteno e copolimerização de eteno/1-hexeno. Os polímeros obtidos foram caracterizados e suas propriedades foram correlacionadas com as condições da reação de polimerização. As reações de polimerização foram realizadas em três diferentes reatores, sob diferentes condições reação. Várias técnicas analíticas foram empregadas para caracterização dos pré-ligantes, precursores catalíticos, polímeros e suportes obtidos.

La polymérisation des oléfines à l'aide de catalyseurs metallocène est une réaction développée au niveau industriel. Bien que les premiers instants de la réaction aient une importance déterminante pour le procédé, ils n'ont fait l'objet que de très peu de travaux de recherche. Dernièrement, le l'équipe du prof. Mc Kenna a conçu un réacteur de type lit fixe pour étudier en détail ces premiers instants de la réaction. Néanmoins, face à la complexité de la réaction étudiée, un travail de modélisation s'avérait nécessaire afin de mieux appréhender l'ensemble des phénomènes influant sur les résultats et ainsi proposer des améliorations à ce montage expérimental. C'est ce travail qui est présenté dans ce manuscrit. Le premier modèle considère le réacteur comme un calorimètre semi-ouvert sur la matière en entrée, et utilise des lois cinétiques simplifiées. Il a ainsi était démontré que l'augmentation de la température dans le réacteur était un paramètre particulièrement important. Le design a ainsi été modifié en conséquence afin de contrôler l'exothermie de la réaction. Dans un second temps, une étude fine sur les mesures de pression récupérées dans le réacteur a été réalisée mettant en avant que le régime transitoire de montée en pression avait un rôle clef sur cette réaction. L'intégration de ces données a permis d'améliorer le modèle utilisé. Contrairement aux résultats obtenus sur des temps de réaction longs, il a été démontré que la désactivation était plus rapide à basse température lors des premiers instants de la réaction / The behaviour of silica supported metallocene catalyst in the early moments of olefin polymerization is not well understood. The complexity, rapidity and high exothermicity of the reaction impede observation of the kinetics and morphological changes. The fixed bed reactor constructed by McKenna’s group is designed to study these first instants of gas phase olefin polymerisation. The purpose of the modelling work presented is to gain understanding and improve the set-up through better knowledge of the reactor conditions. After a literature survey, the existing set-up was reviewed and analysed. A reactor model was constructed and programmed with polymerisation kinetics represented by a simple relation. The model was validated for individual experiments under optimised conditions. Use of the reactor as a calorimeter was evaluated and a state observer for the polymerisation rate was tested. The model was also used to show that very high temperatures are possible in the reactor bed and to simulate effects of changes to reactor construction and operating conditions. The reactor pressurisation profile is non negligible for experiments of shorter duration. New kinetics based on this were incorporated into the model: these were able to represent series of experiments and take account of the deactivation reaction. Contrary to results from longer duration experiments, our model finds initial deactivation does not appear to be controlled by temperature

Ce manuscrit est consacré à l'élaboration de phases stationnaires monolithiques organiques pour lesmicrosystèmes électrochromatographiques plastiques. La partie bibliographique situe d'abord l'intérêt destechniques électrocinétiques en microsystème. Ensuite, l'état de l'art sur l'utilisation des monolithes dans cestechniques séparatives est présenté en portant une attention particulière à la description du processus dephotopolymérisation. La fonctionnalisation de surface du copolymère d'oléfine cyclique (COC) est ensuitedétaillée afin d'envisager l'ancrage du monolithe aux parois du canal.La partie expérimentale a porté tout d'abord sur le développement et la caractérisation de deux monolithesacrylates dédiés à la chromatographie à polarités des phases inversées. Le travail expérimental s'est ensuiteorienté vers le développement d’un nouveau procédé permettant la synthèse et l’ancrage du monolithe dansles microcanaux en COC, ceci en une seule étape et à partir des photoinitiateurs de type I. Ce protocolepermet l'obtention d'efficacités intéressantes qui restent cependant inférieures à celles obtenues en capillaire.Des adaptations des conditions d'irradiation ont alors été apportées pour la synthèse de ces monolithes àl’intérieur des microsystèmes afin d'obtenir des efficacités de l’ordre de 250 000 plateaux/m. Pour terminer,les domaines d'applications et la longévité du dispositif ont été illustrés par la séparation de différentesfamilles de solutés (PAH, mycotoxines, catécholamines, acides aminés, amines biogènes) et l'analysed'échantillons réels tels que les vins (pour déterminer la teneur en certaines amines biogènes : histamine ettyramine). / This manuscript is dedicated to the synthesis of organic monolithic stationary phases in plasticelectrochromatographic microchips. The bibliography part shows the benefit of electrokinetic techniques formicrosystems. After an overview on the use of monoliths in separation techniques, the manuscript is focusedon the description of photopolymerization process. Finally, a detailed review of the different protocols offunctionnalization of cyclic olefin copolymer (COC) surface to allow anchoring of the monolith to thechannel walls is produced.The experimental study firstly deals with the development and characterization of two acrylate monolithsdedicated to the reversed phase mode in chromatography. Then, the experimental part focus on a new onestepmethod for the simultaneous synthesis and anchoring of organic monolith inside COC microchipchannel, thanks to the use of type I photoinitiators. This protocol improves efficiencies which neverthelessstay below those obtained in capillary. Further, the adjustment of the irradiation conditions allows to reachup to 250 000 plates/m. Finally, the field of applications and the durability of microsystem have beenillustrated by the separation of different kinds of solutes (HAP, mycotoxins, catecholamines, biogenicamines) and the analysis of real matrices such as wine samples (for the quantitative determination of twobiogenic amines : histamine and tyramine).

Lower C2–C4 olefins are important commodity chemicals usually produced by steam cracking of naphtha or fluid catalytic cracking of vacuum gas oil. The Fischer–Tropsch synthesis of lower olefins (FTO) with iron-based catalysts uses synthesis gas as an alternative feedstock. Nanostructured carbon materials are widely applied as supports for the iron nanoparticles due to their weak interaction with the metal species, facilitating the formation of catalytically active iron carbide. Numerous synthetic approaches towards carbon-supported FTO catalysts with various structures and properties have been published in recent years but structure-performance relationships remain poorly understood. We apply ordered mesoporous carbon (CMK-3) as a support material with well-defined pore structure to investigate the relationships between calcination/activation conditions and catalytic properties. After loading of iron and sodium/sulfur as the promoters, the structures and properties of the FTO catalysts are varied by using different calcination (300–1000 °C) and activation (350 or 450 °C) temperatures followed by FTO testing at 1 bar, 350 °C, H2/CO = 1. Carbothermal reduction of iron oxides by the support material occurs at calcination temperatures of 800 or 1000 °C, leading to a higher ratio of catalytically active iron(carbide) species but the catalytic activity remains low due to particle growth and blocking of the catalytically active sites with dense graphite layers. For the samples calcined at 300 and 500 °C, the formation of non-blocked iron carbide can be enhanced by activation at higher temperatures, leading to higher catalytic activity. Olefin selectivities of ∼60%C in the formed hydrocarbons with methane of ∼10%C are achieved for all catalysts under FTO conditions at low CO conversion. The influence of the calcination temperature is further investigated under industrially relevant FTO conditions. Promoted CMK-3-supported catalysts obtained at low calcination temperatures of 300–500 °C show stable operation for 140 h of time on stream at 10 bar, 340 °C, H2/CO = 2.

Taxol™, isolated from the bark of Taxus brevifolia in the late 1960s, and the semisynthetic analog Taxotere™ have proven clinical importance for the treatment of ovarian and breast cancer. Taxol™ exerts its biological effect by binding to polymerized tubulin and stabilizing the resulting microtubules. Studies aimed at understanding the biologically active conformation of taxol and its binding environment on β-tubulin are described. This knowledge is important because it could lead to the design of structurally less complicated drugs with better efficacy and better bioavailability. Moreover, the information can be extended to other natural products that possess microtubule-stabilizing properties similar to Taxol™. In this work, the synthesis of a triply labeled taxol analog is described as well as REDOR studies of this compound complexed to tubulin are in progress. Macrocyclic analogs of taxol have been prepared and their biological activities were evaluated. Chemical modeling of these analogs and their activities agrees with the hypothesis that Taxol™ adopts T-shaped conformation. Difficulties were encountered with the key ring-closing metathesis strategy, suggesting that a more flexible and efficient macrocyclization method will be needed to synthesize additional macrocyclic analogs. / Ph. D.