Développée il y a vingt ans par le professeur Grätzel, la technologie des cellules solaires à colorant constitue une alternative intéressante aux panneaux solaires à base de silicium communément commercialisés. Contrairement aux cellules photovoltaïques conventionnelles, le fonctionnement de ces dispositifs repose sur un principe inspiré de la photosynthèse naturelle. En effet, basés sur la sensibilisation de l’oxyde de titane par un colorant absorbant la lumière du soleil à l’instar de la chlorophylle chez les plantes, ces dispositifs permettent d’atteindre des rendements de conversion de l’énergie solaire en électricité de plus de 10% pour des coûts de production relativement bas. Ces travaux de thèse concernent la synthèse de nouveaux complexes de ruthénium porteurs de ligands terpyridines. Les ligands terpyridines ont été préparés par une méthode simple et douce. Une nouvelle voie de synthèse du ligand 4,4’,4’’-tricarboxy-2,2’ :6’,2’’-terpyridine (H3tcterpy) a été développée et comparée à la voie initiale en utilisant les critères de la chimie verte. Les complexes obtenus à partir de ces ligands ont été étudiés par spectroscopie d’absorption UV-visible, d’émission et par électrochimie afin de déterminer leur réponse spectrale ainsi que leurs propriétés énergétiques. Certains colorants ont été testés au sein de cellules photovoltaïques atteignant des performances allant jusqu’à 5,57% de rendement de conversion de l’énergie solaire en électricité. / Developed twenty years ago by Prof Grätzel, Dye sensitized solar cells are an interesting alternative to the commonly commercialized silicon based solar panels. Unlike conventional solar cells, the operation principle of these devices is based from natural photosynthesis. Indeed, based on the sensitization of titanium dioxide by a dye that absorbs solar light such as chlorophyll from plants, these devices can reach solar energy to electricity conversion yield above 10% with low production costs. This PhD project deals with the synthesis of new ruthenium complexes bearing terpyridine ligands. Terpyridine ligands have been prepared by a straightforward and mild method. A new route has been developed for the synthesis of 4,4’,4’’-tricarboxy-2,2’ :6’,2’’-terpyridine (H3tcterpy) and compared to the initial pathway using green chemistry criteria. The complexes obtained from these ligands have been studied by UV-visible and emission spectroscopies and electrochemistry with a view to determine their spectral responses and their energetic properties. Some of these dyes have been tested in dye sensitized solar cells, reaching solar energy conversion to electricity yields up to 5.57%.

La Chimie Verte s’engage entre autres à mettre au point des procédés plus respectueux de l’environnement et à émanciper de la pétrochimie les filières industrielles de fabrication de produits. Dans ce contexte, les enzymes représentent des alternatives de choix pour réaliser des réactions de synthèse de molécules écoresponsable à partir de la biomasse végétale. - L’endoglycocéramidase II de Rhodoccoccus sp. M-777, une glycoside-hydrolase, a été la cible d’un travail d'ingénierie du site actif afin de réorienter son activité hydrolytique vers la synthèse de polyglucosides d’alkyles, de potentiels biosurfactants. Une transglycosylase permettant d’atteindre des rendements de production de plus de 70% a été obtenue. La modélisation de la mutation permet de proposer des pistes sur les raisons de cette inversion du ratio hydrolyse/transglycosylation.- Une stratégie d'évolution dirigée a été appliquée à la féruloyle-estérase A d’Aspergillus niger pour la rendre plus résistante aux chocs thermiques et à la présence de solvants, deux propriétés requises pour utiliser cette enzyme pour des réactions de transfert dans des conditions thermodynamiquement favorables. Un catalogue d’enzymes améliorées, pour les deux propriétés, a été obtenu. L'accumulation de ces connaissances permettra de pouvoir plus efficacement rationaliser le design de biocatalyseur pour la synthèse de molécules, en accord avec les attentes de la chimie verte. / Green chemistry promotes the development of more environmentally friendly processes and the ending of polluting petrochemical industries by promoting the use of renewable resources. In this context, enzymes represent interesting alternatives catalysts for chemical transformations. Notably, they constitute tools of choice for synthesis of organic molecules from plant biomass.- Endoglycoceramidase II from Rhodococcus sp. M-777, a retaining glycoside hydrolase, was subjected to active-site remodelling in order to reorient its activity towards the synthesis of alkyl-polyglucosides, molecules with potential biosurfactant properties. Thus, an efficient transglycosylase able to reach production yield of more than 70% of alkyl-cellobiosides was obtained. A modelling study help to identify the determinants of this complete reversion of the transfer / hydrolysis ratio.- A directed evolution strategy was applied to Aspergillus niger feruloyl-esterase A, in order to make it more resistant to heat shocks and to the presence of solvents, two prerequisites to use this enzyme for transfer reactions under thermodynamically favourable conditions. This led to the establishment of a catalog of optimized enzymes for their thermostability, their solvent resistance, or both properties.These results will pave the way towards a more efficient way to rationally design biocatalysts meeting the expectations of green chemistry.

Les sels de diazoniums sont des électrophiles particulièrement réactifs et versatiles. Leur réputation de composés instables a malheureusement limité leur utilisation en synthèse organique. Au cours de ce projet de thèse, de nouvelles méthodologies plus sûres pour la mise en oeuvre de sels de diazoniums pour des couplages organométalliques ont été découvertes. Ces recherches impliquent des couplages carbone-carbone catalysés au Palladium ainsi que des réactions de C-H arylation à l'aide d'une catalyse au cuivre. Le développement de nouveaux catalyseurs sur supports carbonés constitue aussi une composante majeure de ces travaux. Ainsi, de nouveaux catalyseurs hétérogènes ont été développés pour la réaction de Meerwein. Enfin, des recherches ont été menées pour le développement de nouveaux supports actifs comme nano-réacteurs en synthèse organométallique. / Diazonium salts are reactive and versatile when used as electrophiles. Unfortunately, their reputation as instable compounds strongly limited their use in chemical synthesis. This work lead to the discovery of new procedure for a safer and more environmentally friendly use of diazonium salts in organometallic coupling reactions. We studied palladium catalised carbon-carbon coupling reactions and copper catalyzed C-H arylatons. A major part of this work is also focalized in the development of new heterogeneous catalysts. New catalysts for the Meerwein reaction were also discovered. Finally, the last part of this research work focused on new active heterogeneous supports as nanoreactors for organometallic reactions.

The need to reduce humankind reliance on fossil fuels by exploiting sustainably the planet renewable resources is a major driving force determining the focus of modern material research. For this reason great interest is nowadays focused on finding alternatives to fossil fuels derived products/materials. For the short term the most promising substitute is undoubtedly biomass, since it is the only renewable and sustainable alternative to fossil fuels as carbon source. As a consequence efforts, aimed at finding new synthetic approaches to convert biomass and its derivatives into carbon-based materials, are constantly increasing. In this regard, hydrothermal carbonisation (HTC) has shown to be an effective means of conversion of biomass-derived precursors into functional carbon materials. However the attempts to convert raw biomass, in particular lignocellulosic one, directly into such products have certainly been rarer. Unlocking the direct use of these raw materials as carbon precursors would definitely be beneficial in terms of HTC sustainability. For this reason, in this thesis the HTC of carbohydrate and protein-rich biomass was systematically investigated, in order to obtain more insights on the potentials of this thermochemical processing technique in relation to the production of functional carbon materials from crude biomass. First a detailed investigation on the HTC conversion mechanism of lignocellulosic biomass and its single components (i.e. cellulose, lignin) was developed based on a comparison with glucose HTC, which was adopted as a reference model. In the glucose case it was demonstrated that varying the HTC temperature allowed tuning the chemical structure of the synthesised carbon materials from a highly cross-linked furan-based structure (T = 180oC) to a carbon framework composed of polyaromatic arene-like domains. When cellulose or lignocellulosic biomass was used as carbon precursor, the furan rich structure could not be isolated at any of the investigated processing conditions. These evidences were indicative of a different HTC conversion mechanism for cellulose, involving reactions that are commonly observed during pyrolytic processes. The evolution of glucose-derived HTC carbon chemical structure upon pyrolysis was also investigated. These studies revealed that upon heat treatment (Investigated temperatures 350 – 900 oC) the furan-based structure was progressively converted into highly curved aromatic pre-graphenic domains. This thermal degradation process was observed to produce an increasingly more hydrophobic surface and considerable microporosity within the HTC carbon structure. In order to introduce porosity in the HTC carbons derived from lignocellulosic biomass, KOH chemical activation was investigated as an HTC post-synthesis functionalisation step. These studies demonstrated that HTC carbons are excellent precursors for the production of highly microporous activated carbons (ACs) and that the porosity development upon KOH chemical activation is dependent on the chemical structure of the HTC carbon, tuned by employing different HTC temperatures. Preliminary testing of the ACs for CO2 capture or high pressure CH4 storage yielded very promising results, since the measured uptakes of both adsorbates (i.e. CO2 and CH4) were comparable to top-performing and commercially available adsorbents, usually employed for these end-applications. The combined use of HTC and KOH chemical activation was also employed to produce highly microporous N-doped ACs from microalgae. The hydrothermal treatment of the microalgae substrate was observed to cause the depletion of the protein and carbohydrate fractions and the near complete loss (i.e. 90%) of the microalgae N-content, as liquid hydrolysis/degradation products. The obtained carbonaceous product showed a predominantly aliphatic character indicating the presence of alkyl chains presumably derived from the lipid fractions. Addition of glucose to the initial reaction mixture was found out to be extremely beneficial, because it allowed the fixation of a higher N amount, in the algae derived HTC carbons (i.e.  60%), and the attainment of higher product yields (50%). Both positive effects were attributed to Maillard type cascade reactions taking place between the monosaccharides and the microalgae derived liquid hydrolysis/degradation products, which were in this way recovered from the liquid phase. KOH chemical activation of the microalgae/glucose mixture derived HTC carbons produced highly microporous N-doped carbons. Although the activation process led to a major reduction of the N-content, the retained N-amount in the ACs was still considerable. These features render these materials ideal candidates for supercapacitors electrodes, since they provide extremely high surface areas, for the formation of electric double-layer, coupled to abundant heteroatom doping (i.e. N and O) necessary to obtain a pseudocapacitance contribution. / Die Notwendigkeit, die Abhängigkeit der Menschheit von fossilen Brennstoffen zu reduzieren ist die treibende Kraft hinter aktuellen Forschungsanstrengungen in den Materialwissenschaften. Folglich besteht heutzutage ein erhebliches Interesse daran Alternativen zu Materialien, die aus fossilen Resourcen gewonnen werden, zu finden. Kurzfristig ist zweifellos Biomasse die vielversprechendste Alternative, da sie aus heutiger Sicht die einzige nicht-fossile, nachhaltige und nachwachsende Kohlenstoffquelle ist. Konsequenterweise werden die Antrengungen neue Syntheseansätze zur Konvertierung von Biomasse und ihren Derivaten in kohlenstoffbasierten Materialien forwährend erhöht. In diesem Zusammenhang hat sich die Hydrothermalkarbonisierung (HTC) als sehr vielseitiges Werkzeug zur Konvertierung von Biomasse-basierten Ausgangsstoffen in funktionale Kohlenstoffmaterialien herausgestellt. Dennoch gibt es bisher wenige Ansätze um rohe Biomasse, genauer gesagt Lignicellulose, direkt in funktionale Materialien umzusetzen. Könnte der direkte Einsatz von roher Biomasse Verfahren wie der HTC zugänglich gemacht werden, würde dies die Nachhaltigkeit des Verfahrens immens steigern. Daher wurde in dieser Dissertation die Hydrothermalkarbonisierung von kohlenhydratreicher (d. h. Lignicelluse) und proteinreicher (d. h. Microalgae) Biomasse systematisch analysiert. Diese Untersuchung galt dem Ziel einen besseren Einblick in das Potential dieser thermochemischen Verarbeitungsmethode funktionale Kohlenstoffmaterialien aus unverarbeiteter Biomasse hervorzubringen zu gewinnen. Die hergestellten Materialien wurden mittels chemischer Aktivierung nachträglich weiter behandelt. Dieser zusätzliche Verarbeitungsschritt ermöglichte die Herstellung hochporöser aktiverter Kohlenstoffe (AC). Die aus Lignicellulose gewonnenen ACs zeigten exzellente Eigenschaften bei der Aufnahme von CO2 und der Hochdruckspeicherung von CH4 währen die aus Microalgae gewonnen Eigenschaften an den Tag legten (z. B. hohe Oberfläche und N-Dotierung), welche sie zu vielversprechenden Materialien für Superkondensatoren machen. Die in dieser Dissertation präsentierte Arbeit zeigte außergewöhnliche Fortschritte in Richtung der Anwendung von unbehandelter Biomasse als Ausgangsmaterial für die Produktion von funktionalen Kohlenstoffen.

Homogenous acid catalysts are prevalent throughout the chemical industry but all have the drawback of requiring post reaction neutralization and subsequent downstream removal of the product salt. The use of a base to neutralize the acid and the processing of the salt are ancillary to the process and the disposal of the salt is an environmental concern. The work presented here shows the use of alkylcarbonic acids, which form in situ with CO₂ pressure and neutralize on loss of CO₂ pressure rather than requiring a base. Thus CO₂ can be used to "switch" the acid on and off. The properties of alkylcarbonic acids are explored to gain understanding of the mechanisms by which they act. The acids are also used to catalyze the synthesis of α-pinene, methyl yellow, and benzyl iodide. These reactions are examples of common acid catalyzed reactions where this technology could be implemented. The second half of the work explores two other "switches". The first is using temperature to break an emulsion with a novel thermally cleavable surfactant. This technology has potential applications in a wide range of fields where surfactants are used including polymerization, oil recovery, and biosynthesis. The second is using CO₂ to liquefy a solid ionic compound to allow its use as a solvent. This would greatly increase the number of ionic species available for use in ionic liquid-CO₂ biphasic systems.

In this research project, reduction or complete elimination of organic solvents is explored in the synthesis of cyclic imides using a technique that brings reagents into favorable position to react. Cocrystal Controlled Solid-State Synthesis (C3Sy3), takes advantage of supramolecular interactions such as hydrogen bonding and π-π stacking to form a cocrystal which can sequential be heated to complete the condensation reaction and produce a desirable product. Twenty-five successful condensation reactions result in high and clean yield. C3Sy3 of cyclic imides with auxiliary hydrogen bonding moieties like carboxylic acid, carboxylate or pyridyl groups are amenable to form additional solid-state materials. These moieties are useful in forming coordinate covalent bonds with metal cations. Using these C3Sy3 synthesized molecules as ligands, various Metal-Organic Materials (MOMs) are self-assembled. These MOMs offer unique qualities owing to the properties of the cyclic imides. With the addition of accessible carbonyl groups, they may participate as hydrogen bond acceptors or hydrophilic groups. Various degrees of rotation of N-phenyl substituents around the imide plane allow for structural flexibility as a route to supramolecular isomers in MOMs. The ease in imide synthesis may allow the fast scale-up of these ligands for industrial application. Similar ligands are generally synthesized by cross-coupling or substitution reactions that require expensive catalyst and various organic solvents. Metal-organic materials are a class of compounds amenable to crystal engineering owing to the directional coordinate covalent bonds between metal or metal clusters and organic ligands. They are characterized by X-ray diffraction, spectroscopy, volumetric and gravimetric analysis. The C3Sy3 imides were used to construct various MOMs, from discrete nanostructures to extended 3-periodic frameworks that possess viable internal space for applications pertaining to porous materials. Structural characterization by single crystal X-ray diffraction and structure-function relations are addressed. Gas sorption experiments show that many of these materials are structurally robust and retain crystallinity after evacuation. Ion exchange and guest uptake experiments using the synthesized materials demonstrate their potential as agents for sequestration. The bottom-up synthesis of metal-organics materials is leading the field of crystal engineering with built-in properties, showing promise by combining attributes from both inorganic and organic components.

Nowadays, the modern chemical industry has to deal with increasing environmental concerns, including the disposal of waste and its economic impact, or the diminution of important worldwide resources such as transition metals. In this Ph.D. thesis, we aimed to bring improvement in this area by the development of green processes, based on the use of recyclable heterogeneous catalysts. By combining the catalytic properties of several metal cations with the properties of solid catalysts such as polyoxometalates or zeolites, we were able to set up new tools for organic synthesis. Silver-doped polyoxometalates proved to be very efficient catalysts in the rearrangement of alkynyloxiranes to furans. Acetals and spiroketals were synthetized by dihydroalkoxylation of alkynediols under catalysis with silver-zeolites. As a perspective, we highlighted the potential applications of such green procedures in the total synthesis of more complex molecules. The first results suggested that these environmental friendly processes should gain increasing interest in the future.

Orientador: Hérida Regina Nunes Salgado / Banca: Anil Kumar Singh / Banca: Álvaro José dos Santos Neto / Banca: Carlos Henriquer Gomes Martins / Banca: Marlus Chorilli / Resumo: O ertapenem sódico é um antimicrobiano da classe dos carbapenêmicos, disponível comercialmente na forma de pó liofilizado para solução injetável. Apresenta ação contra bactérias Gram-negativas, Gram-positivas, aeróbias e anaeróbias. O objetivo do trabalho foi desenvolver métodos qualitativos e quantitativos para avaliação de ertapenem sódico. O ertapenem sódico foi caracterizado quanto ao seu aspecto físico, solubilidade, teor de umidade, ponto de fusão, por métodos espectrofotométricos e cromatográficos. Sete métodos quantitativos foram desenvolvidos e validados. O método de espectrofotometria na região ultravioleta foi desenvolvido utilizando água purificada como solvente e obteve regressão linear de y = 0,0219x -0,0017 e R2 0,9999. O método por espectrofotometria na região do infravermelho, apresentou regressão linear de y = 0,5141x + 0,021 e R2 = 0,9993. Dentre os métodos cromatográficos foi desenvolvido método cromatografia com interação hidrofílica; cromatografia líquida de alta eficiência em fase reversa e cromatografia em fluido supercrítico. O método de cromatografia com interação hidrofílica foi desenvolvido, utilizando como fase móvel A: acetonitrila e B: água (88:12 v/v) 0,1 % de ácido fórmico pH 2,5, no modo isocrático, a regressão linear foi y = 29928 x - 547879, e R2 = 0,9994, enquanto que para o método por cromatografia líquida em fase reversa a fase móvel utilizada foi A: água e B: etanol (80:20 v/v) com 0,1% de ácido fórmico pH 2,5 no modo isocrático, a regr... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Ertapenem sodium is an antimicrobial from the carbapenems class, commercially available in lyophilized powder form for injectable solution. It exhibits action against Gram-negative, Gram-positive, aerobic and anaerobic bacteria. The ertapenem sodium was characterized for its physical appearance, solubility, moisture content, melting point, by spectroscopic and chromatographic methods. Seven quantitative methods have been developed and validated. The method by spectroscopy on the ultraviolet region was developed using purified water as solvent and obtained linear regression of y = 0.0219x - 0.0017, R2 = 0.9999. For the method for spectroscopy in the infrared region, KBr pellets were prepared and measured, and the linear regression was y = 0.021 + 0.5141x, R2 = 0.9993. Among the chromatographic methods, a hydrophilic interaction liquid chromatography method was developed; reversed-phase highperformance liquid chromatography, and supercritical fluid chromatography. The hydrophilic interaction liquid chromatography was developed using as mobile phase A: acetonitrile and B: water (88:12 v/v) 0.1% formic acid pH 2.5, in isocratic mode, linear regression was y = 29928x - 547879, R2 = 0.9994. Whereas the method by reversed-phase high-performance liquid chromatography to the mobile phase was used A: water and B: ethanol (80:20 v/v) with 0.1% formic acid pH 2.5 in isocratic mode, linear regression was y = 23043x - 38525, and R2 = 0.9999. Regarding the supercritical fluid chromatography... (Complete abstract click electronic access below) / Doutor

No description available.

La nanocatalyse à base de métaux de transition constitue un domaine prometteur pour lequel l'efficacité accrue, le caractère de chimie verte et le recyclage sont activement recherchés. Dans cet esprit, cette thèse a été dédiée à la synthèse, la caractérisation et les applications catalytiques de nouveaux nanomatériaux à base de métaux de transition. D'une part, en catalyse homogène colloïdale, des nanoparticules de métaux de transition stabilisées par des ligands amphiphiles ont procuré d'excellentes performances catalytiques en terme d'activité, stabilité et recyclabilité pour la réduction du nitro-4-phénol, le couplage de Suzuki-Miyaura, le transfert d'hydrogéné et la cyclo-addition entre un alcyne et un azoture dans l'eau. D'autre part, en catalyse hétérogène, le design, la synthèse et les applications catalytiques de nano-catalyseurs basés sur les supports de type graphène ou architectures moléculaires organiques ont également été conduits. Leurs excellentes propriétés catalytiques ont été démontrées pour la réduction du nitro-4-phénol, le couplage de Sonogashira, la cyclo-addition des alcynes avec les azotures et l'hydrolyse d'ammonia-borane avec génération d'hydrogène dans l'eau dans les conditions ambiantes. / Transition metal nanocatalysis is a promising area, where increased efficiency, greenness and reusability are actively sought. In this spirit, the thesis has been devoted to the synthesis, characterization and catalytic applications of new transition metal nanomaterials. Amphiphilic ligand stabilized transition metal nanoparticles catalysts have provided excellent catalytic performances in terms of activity, stability and recyclability in the 4-nitrophenol reduction, Suzuki-Miyaura coupling, transfer hydrogenation and alkyne-azide cycloaddition reactions with low amounts of metal loadings. Moreover, an efficient amphiphilic "click" CuI catalyst was also designed for part-per-million levels of alkyne-azide cycloaddition reaction in water. The design, synthesis and catalytic application of heterogeneous nanocatalysts based on graphene and metal organic framework supports have also been carried out, and their excellent catalytic properties in 4-nitrophenol reduction, Sonogashira coupling, alkyne-azide cycloaddition and hydrolysis of ammonia-borane for hydrogen generation in water under ambient conditions have been disclosed.