Compte tenu du récent taux alarmant d'épuisement des réserves de combustibles fossiles et de l'augmentation drastique des niveaux de CO2 dans l'atmosphère qui a conduit au réchauffement de la planète et à des changements climatiques sévères, l'exploitation de toutes sortes d'énergies renouvelables a été la Parmi les principales priorités de la recherche Champs à travers le monde. L'une des nombreuses voies de ce genre est la réduction du CO2 aux combustibles utilisant des énergies renouvelables, plus communément appelées cellules photoélectro-catalytiques (PEC). Des essais expérimentaux sur la réduction du CO2 ont été réalisés sur différents types de catalyseurs dans les deux cellules (Conçu par un laboratoire) afin de comprendre la sélectivité, la productivité et les produits de réaction obtenus. Des essais expérimentaux ont été réalisés sur différents types de catalyseurs à la fois dans les cellules en phase gazeuse et en phase liquide pour comprendre la sélectivité, la productivité et les produits de réaction obtenus. Pour les études sur la réduction EC du CO2 en phase gazeuse, une série d'électrodes (à base de nanoparticules (NPs) de Cu, Fe, Pt et CuFe déposées sur des nanotubes de carbone ou de noir de carbone puis placées à l'interface entre une membrane Nafion et Une électrode à couche de diffusion de gaz). Les résultats démontrent le type divers de produits formés et leurs productivités. Dans des conditions sans électrolyte, la formation de produits ≥C1 tels que l'éthanol, l'acétone et l'isopropanol a été observée la plus élevée étant pour Fe et suivie de près par Pt. Pour améliorer Combustibles nets, un ensemble différent d'électrodes a été préparé sur la base de revêtements MOF de type imidazolate de type zéolitique substitué (SIM-1) (Fe-CNT, Pt-CNT et CuFe-CNT basés sur MOF) Et Pt-MOF a montré des carburants améliorés. En se reportant aux études sur la réduction EC du CO2 dans une cellule en phase liquide, un ensemble similaire d'électrodes a été prepare (NP - Cu, Fe, Pt, Ru, Co déposées sur des nanotubes de carbone ou du noir de carbone ont). Pour les conditions de phase liquide, en termes de produits C nets, les électrodes catalytiques à base de Pt sont en tête de la catégorie, suivies de près par Ru et Cu, tandis que Fe a obtenu la position la plus basse. Le mécanisme réactionnel sous-jacent probable a également été fourni. Afin d'améliorer encore les performances, on a synthétisé des NP de metal (Ru, Fe, Pt et Cu) de différentes tailles en utilisant différentes techniques de synthèse: (i) l'itinéraire d'imprégnation (ImR) pour obtenir des NP dans la plage de tailles de 10 à 50 nm; (Ii) Approche organométallique (OM) pour synthétiser des NPs uniformes et ultrafines dans la plage de tailles de 1-5 nm. Fe ont été synthétisés par une nouvelle voie de synthèse et des conditions pour atteindre des NP de 1 à 3 nm. (Iii) Approche de haut en bas de Nanowire pour obtenir des NP de cuivre ultrafin dans la plage de taille de 2-3,8 nm. Les améliorations apportées à la productivité du carburant se sont révélées être de 5 à 30 fois plus élevées pour les petites NP sur les NP plus importantes et, en outre, une charge réduite de 10 à 1-2% en poids. Un autre ensemble d'électrodes à base de nano-mousses (Cu NF et Fe NF sur Feuille de Cu, Feuille de Foie, Al Foil, Inconel foil et Al grid / mesh) préparés par électrodéposition ont également été étudiés afin d'améliorer encore la conversion de CO2 / carburant. Après, l'optimisation du dépôt et de la tension à l'aide de la voltamétrie cyclique, les carburants se sont améliorés de 2 à 10 fois par rapport aux combustibles nets les plus élevés obtenus à l'aide d'électrodes CNT dopées à base de NP / In view of the recent alarming rate of depletion of fossil fuel reserves and the drastic rise in the CO2 levels in the atmosphere leading to global warming and severe climate changes, tapping into all kinds of renewable energy sources has been among the top priorities in the research fields across the globe. One of the many such pathways is CO2 reduction to fuels using renewable energies, more commonly referred as photo-electro-catalytic (PEC) cells. Experimental tests were carried out on various types of catalysts in both the gas and liquid phase cells (lab-designed) to understand the different selectivity, productivity and the reaction products obtained. For the studies on the EC reduction of CO2 in gas phase cell, a series of electrodes (based on Cu, Fe, Pt and Cu/Fe metal nanoparticles – NPs - deposited on carbon nanotubes – CNTs - or carbon black and then placed at the interface between a Nafion membrane and a gas-diffusion-layer) were prepared. Under gas phase, the formation of ≥C1 products (such as ethanol, acetone and isopropanol) were observed, the highest being for Fe and closely followed by Pt, evidencing that also non-noble metals can be used as efficient catalysts under these conditions. To enhance the net fuels, a different set of electrodes were also prepared based on substituted Zeolitic Imidazolate (SIM-1) type MOF coatings (MOF-based Fe-CNTs, Pt-CNTs and Cu/Fe-CNTs) and Pt-MOF showed improved fuels. Moving to the studies on the EC reduction of CO2 in liquid phase cell, a similar set of electrodes were prepared (metal NPs of Cu, Fe, Pt, Ru and Co deposited on CNTs or carbon black). For liquid phase conditions, in terms of net C-products, catalytic electrodes based on Pt topped the class, closely followed by Ru and Cu, while Fe got the lowest position. The probable underlying reaction mechanism was also provided. In order to improve further the performances, varied sized metal NPs (Ru, Fe, Pt and Cu) have been synthesized using different techniques: (i) impregnation (ImR) route to achieve NPs in the size range of 10-50 nm; (ii) organometallic (OM) approach to synthesize uniform and ultrafine NPs in the size range of 1-5 nm (i.e., Fe NPs were synthesized through a novel synthesis route to attain 1-3 nm NPs); (iii) Nanowire (NW) top-down approach to obtain ultrafine copper metal NPs in the size range of 2-3.8 nm. The enhancements in the fuel productivity were found to be 5-30 times higher for the smaller metal NPs over the larger metal NPs and moreover, with reduced metal loading from 10 to 1-2 wt %. A different set of electrodes based on nano-foams (Cu NF and Fe NF on Cu foil, Fe foil, Al foil, Inconel foil and Al grid/mesh) prepared via electro-deposition were also investigated, to further improve CO2 to fuels conversion. After, optimization of deposition and voltage using cyclic voltammetry, the fuels improved by 2-10 times over the highest net fuels achieved using metal NPs doped CNT electrodes

Les hydrocarbures aromatiques polycycliques (HAP) sont des polluants persistants retrouvés majoritairement dans l’environnement, qui sont reconnus comme hautement toxiques pour les organismes vivants. Les nombreux travaux réalisés sur les mécanismes contrôlant l’évolution des HAP dans le sol et dans la rhizosphère ont mis en exergue le rôle majeur de la biodégradation par les microorganismes et de la sorption aux constituants du sol. Néanmoins, un manque d’informations persiste concernant le devenir de ces HAP dans le sol, et plus particulièrement leur localisation dans les compartiments du sol ainsi que la nature et le comportement des composés issus de leur dégradation. La thèse avait donc comme principaux objectifs : (a) la localisation des HAP et des produits dérivés dans les compartiments du sol (matières organiques, phases minérales, microorganismes et plante), et (b) la quantification et l’identification des composés organiques formant les résidus liés du sol. Pour cela, nous avons couplé deux approches:(i) le suivi d’un HAP modèle marqué, le 13C-phénanthrène (13C-PHE), dans un sol artificiellement contaminé planté et non planté pour notamment déterminer par IRMS et NanoSIMS la distribution du C issu du PHE dans les compartiments et pour identifier les composés dérivés du 13C-PHE par 13C-RMN et TD/pyGCMS. (ii) le suivi d’une contamination ancienne et récente en HAP dans un sol historiquement contaminé pour étudier l’influence des matières organiques et des phases minérales (séparées par un fractionnement densimétrique) dans la rétention des HAP. Plus de 40% du C issu du 13C-PHE est retenu dans le sol après 14 jours de croissance du ray-grass. L’enrichissement en 13C observé dans la plante est du même ordre que celui du sol (E13C ≈ 0.04 % at.) démontrant une incorporation homogène du 13C-PHE entre la plante et le sol. Cet enrichissement global dans la plante est confirmé par les images NanoSIMS réalisées sur les racines. Des hotspots en 13C ont également été observés dans la rhizosphère, et à partir de leur taille, leur forme et leur composition élémentaire en C, N et S ils ont été identifiés comme étant des bactéries, ce qui met en avant leur rôle dans la dynamique des HAP du sol. Dans le sol industriel, la majorité des HAP est retrouvée dans les MO non complexées aux minéraux. En revanche, les HAP fraîchement ajoutés se sont significativement liés aux associations organo-minérales composées de quartz, de feldspaths et de phyllosilicates / Polycyclic aromatic hydrocarbons (PAHs) are major persistent pollutants in the environment that are recognized as highly toxic to living organisms. Numerous studies were carried out on the fate of PAHs in soil and in plant rhizosphere and highlighted the major contribution of biodegradation processes and of the sorption to soil constituents. However, a lack of knowledge remains about the fate of PAHs in the soil and especially their location in soil compartments as well as the nature and the behavior of degradation products. The main objectives of the thesis were: (a) to localize PAHs and their derived products within soil compartments (organic matter, minerals, microorganisms and plant), and (b) to quantify and identify the organic compounds forming bound residues. For this purpose, we used two approaches: (i) the monitoring of a labeled PAH, the 13C-phenanthrene (13C-PHE), in a spiked soil planted or not to determine by IRMS and NanoSIMS the 13C-distribution into compartments and to identify derived compounds of 13C-PHE by 13C-RMN et TD/pyGCMS. (ii) the distribution and localization of aged and freshly spiked PAH contamination in a brownfield soil to study the impact of organic matter and minerals (using soil densimetric fractionation) in the PAH retention. More than 40% of C from 13C-PHE remained in the soil after 14 days of ryegrass growth. The 13C-enrichment in plant tissue was similarly to the soil enrichment (E13C ≈ 0.04 at.%) indicating uniform uptake of 13C-PHE between the soil and plant. NanoSIMS images acquired for roots confirmed this global enrichment in the plant. 13C-Hospots were also observed in the rhizosphere, and on the basis on their size, their shape and their elemental composition in C, N and S, they were identified as bacteria, which emphasize their contribution to the fate of PAHs in soil. In the industrial soil, most of the PAHs were found attached to the free OM. However, the freshly spiked PAHs in the soil were significantly associated with organo-mineral associations containing quartz, feldspars and phyllosilicates

O desenvolvimento desta tese foi direcionado ao estudo da química iônica, em fase gasosa, de alguns compostos organo-metálicos, como: Ge(OEt)4, Ti(i-Pro)4, BU3SnOMe, GeE4, GeMe4, SiMe4 e Me6Si2NH. Foram abordados vários aspectos da química iônica destes compostos desde o estudo dos seus processos de fragmentação, a reatividade de cátions e ânions derivados destes compostos, a fotodisssociação de espécies hipervalentes formadas a partir de reações de adição, e por último foram obtidos dados sobre a afinidade protônica de ânions derivados de germânio. Além disto, foram promovidas outras investigações experimentais destinadas á obtenção de informações sobre a estrutura de espécies hipervalentes e a análise de substâncias químicas desconhecidas contendo átomos de Ge. Os resultados obtidos em algumas investigações são conclusivos, e por isto em alguns casos não foi criada uma seção voltada exclusivamente para as conclusões. Mesmo assim, algumas observações podem ser destacadas. De modo geral, os alcóxidos metálicos reagem com íon fluoreto através de reações de adição-eliminação formando complexos pentacoordenados, que no caso dos derivados de germânio e titânio, absorvem radiação infravermelha de um laser de CO2, e por absorção multifotônica promovem sucessivos processos de eliminação de espécies neutras simples. O mesmo comportamento não é observado nas alquilas metálicas. Os cátions derivados destes compostos são poderosos ácidos de Lewis, e sofrem reações de adição-eliminação com diversos substratos neutros, do tipo base de Lewis. O mais surpreendente foi à observação de reações de abstração de ligantes como CH3- por alguns destes cátions, e a subseqüente formação, em alguns casos, de espécies formadas através de reações de troca de ligantes. A afinidade protônica de alguns ânions formados através da fotodissociação de espécies hipervalentes, derivadas de germânio, foi obtida por meio de reações de abstração de prótons com substratos de afinidade protônica conhecida. Foi possível caracterizar a acidez dos ácidos conjugados destes ánions como sendo próxima a das mercaptanas. / The present thesis describes the study of the gas-phase ion chemistry of a number of organometallic compounds such as Ge(OEt)4, Ti(i-Pro)4, BU3SnOMe, GeE4, GeMe4, SiMe4 and Me6Si2NH. Several aspects of the ion chemistry of these compounds were investigated including fragmentation processes in their mass spectra, reactivity of cations and anions obtained from these compounds by electron ionization, photodissociation of hypervalent species formed by nucleophilic addition, and the proton affinity of a number of germanium-containing anions. Additional experimental investigations were carried out to characterize the structure of hypervalent studies and to explore analytical applications of unknown germanium-containing substrates. The results in several cases are sufficiently conclusive such that a general section of conclusions was considered unnecessary. For example, the metal alkoxides studied in this work react with fluoride ion in the gas-phase by an addition-elimination mechanism that initially results in the formation of a pentacoordinated species. The germanium and titanium pentacoordinated species absorb readily infrared radiation from a CO2 laser and undergo successive elimination of sim pie neturals by sequential mutiphoton absorption. This behavior is not observed for the metal alkyls. Cations derived from these compounds are powerful Lewis acids and are capable of promoting addition-elimination reactions with several neutral substrates that can act as Lewis bases. The most surprising reactions have been the abstraction of methide (formally a CH3- ion) by some of these cations followed, in the case of some Si- and Ge-containing ions, by a ligand exchange reaction. The proton affinity of Ge-containing anions obtained from the photodissociation of hypervalent precursors was established using the bracketing technique by studying the proton abstraction reaction with a number of substrates of well-known proton affinities. The absolute values derived for the proton affinities of these species, and the corresponding gas-phase acidities of the conjugate acids are close to the values of similar mercaptans.

This paper builds on previous research of aminoclay complexes in undergraduate studies. Theoretical part deals with study of current problems of aminoclay complexes with bioactive substances and the choice of substances for complexing with aminoclay. The experimental part consists of preparation of aminoclay complexes with selected bioactive agents at various concentrations. Verification of binding of bioactive agents to the aminoclay matrix was performed by Elemental Analysis (EA) and Fourier-transform infrared spectroscopy (FT-IR). For finding of the bound amount of bioactive substance were used the Ultra Performance Liquid Chromatography (UPLC®) and analysis of the cytotoxic properties of the formed complexes by used by the MTT assay. The main motivation of this study is to create new complexes with improved characteristics that would replace existing forms of substances used in pharmaceutical and biomedical applications.

Le développement de méthodes de synthèse asymétriques a largement été exploré au cours des vingt dernières années et en particulier par le biais de réactifs organométalliques. Bien que ces processus mènent à d’excellents résultats en terme d’énantiodiscrimination, l’objectif de cette thèse a été de développer de nouveaux outils de synthèse peu onéreux, respectueux des fonctions sensibles environantes et permettant l’accès aux composés attendus avec de bons rendements et excès énantiomériques. Dans cet optique, des triorganozincates de lithium chiraux ont été étudiés. Des méthodes d’alkylation et d’arylation 1,2 énantiosélectives d’aldéhydes, comportant comme partenaire chiral la (R)-N-(2-iso-butoxybenzyl)-1- phenyléthanamine, ont ainsi été développées et mises en application sur divers aldéhydes. Les alcools secondaires correspondants ont été obtenus avec de bons rendements (jusqu'à 83%) et d’excellents excès énantiomériques (jusqu'à 99%). Ces procédures ont ensuite été appliquées à la synthèse asymétrique de produits naturels et/ou bioactifs tels que la Spiromastilactone A, la (R)-Néobénodine et la (R)-Orphénadrine. Par ailleurs, la synthèse de nouveaux ligands de type amino-alcool a été développée dans le but ultime de désymétriser des substrats de type imines cycliques. / The development of new asymetric methodologies have been widely explored during the last twenty years and in particular through organometallic reagents. Although these processes lead to excellent results in terms of enantiodiscrimination, the goal of this thesis was to develop new tools: cheap, chemoselective and allowing the access to the desired compounds with high yields and enantiomeric excesses. In this context, chiral lithium triorganozincates have been studied. Enantioselective nucleophilic 1,2 alkylation and arylation of aldehydes reactions, including (R)-N-(2-iso-butoxybenzyl)-1-phenylethanamine as the chiral ligand, have been optimized toward various aldehydes. The expected secondary chiral alcohols have been obtained with good yields (up to 83%) and high enantiomeric excesses (up to 99%).These processes have been then applied to the asymmetric synthesis of naturals and/or bioactive compounds as Spiromastilactone A, (R)-Neobenodine and (R)-Orphenadrine. Finally, the access to new amino-alcohols have been developed with the ultimate goal to engage those species as the chiral partner when reacting chiral lithium zincates with imines.

O processo Humifert trata material fosfático e orgânico em um reator, com ácido nítrico nascente, para produzir compostos organo -fosfatados cuja solubilidade em P é maior que o material fosfático natural mas menor que os fertilizantes industriais tradicionais. É um processo alternativo de fabricação de fertilizantes que objetiva aproveitar materias fosfáticos de baixo teor ou de difícil tratamento industrial, potencialmente descartados, e também materiais orgânicos diversos, dando finalidade, portanto, a rejeitos e diminuindo, assim, os custos econômicos e ambientais das indústrias de fósforo. Além da solubilidade em P, os compostos formados têm a vantagem de conter matéria orgânica, em geral necessária para os solos tropicais. Este trabalho teve como objetivo a colocação em funcionamento rotineiro do reator Humifert, fabricado pela primeira vez no Brasil, a obtenção de compostos organofosfatados a partir do minério fosfático de Angico dos Dias (BA) e de lodo de esgoto, a caracterização dos compostos obtidos a partir de vários procedimentos (difração de raios X, microscopia óptica e eletrônica, análises químicas microlocalizadas, especfotometria de absorção no infravermelho, análises elementar e de solubilidade do P) e a avaliação da eficiência agronômica em casa de vegetação. A pesquisa insere-se num projeto mais amplo que pretende aprofundar o estudo do processo, visando sua futura aplicação em determinadas condições. Os compostos produzidos demonstraram que a fase mineral da mistura rocha fosfática - matéria orgânica sofre ataque químico progressivo, em períodos de tempo investigados de 2h até 12h, e que os elementos químicos liberados deste ataque associa-se aos produtos secundários presentes, como os compostos ferruginosos, e também à matéria orgânica. Particularmente para a apatita, verificou-se consumo crescente dos grãos com o aumento do tempo de exposição ao ataque, confirmando o funcionamento do equipamento e a ocorrência das reações, e, ainda, a forte associação do P com os agregados de matéria orgânica após o processo, confirmando trabalhos anteriores. Não foram identificadas fases cristalinas neoformadas, embora haja a possibilidade de ter havido formação de fosfato bicálcico ou de outros compostos em alguns dos produtos obtidos. Essas observações são refletidas nos resultados de solubilidade com diferentes extratores (água, ácido cítrico a 2% e citrato neutro de amônio), já que a alteração e o consumo da apatita, relacionados à possível formação de compostos mais solúveis e à associação do P com a matéria orgânica, por adsorção, podem ter contribuído para o aumento da solubilidade nos extratores utilizados. O aumento de solubilidade em P permitiu resultados agronômicos melhores, para o composto Humifert de 12h, do que os demais tratamentos (materiais não processados no reator ou não misturados com matéria orgânica), mostrando que foi capaz de disponibilizar o P liberado da apatita e adsorvido pela matéria orgânica às plantas, embora não tenha sido suficiente para eficiência agronômica comparável ao fosfato monocálcico (FMC, com 100% de solublidade). / The Humifert is a French process involving the attack of a mixture of phosphate rock (PR) and organic matter (OM) through the fresh-forming nitric acid, producing organic-phosphatic compounds with P solubility greater than phosphatic rock and lower than traditional fertlizers. This is an alternative process proffiting low-grade or difficult phosphatic materials, potentially discarded, and several organic materials, giving na application to rejects, and decreasing economical na environmental costs of P industries. More than a good P solubility, the formed compounds have organic matter, which is an advantage for tropical soils. The aim os this reserch was install the first Brazilian Humifert reactor, produce Humifert compounds using Angico dos Dias phosphatic ore and sewage sludge, their characterization by several technicals (X ray diffraction, optical and scanning electronic microscopy, chemical analysis, infrared spectroscopy and P solubility evaluation), and agronomic experimentation in the greenhouse. Data characterization and for solubility and agronomic experimentation suggests that increasing attack occurred in mineral phases, and released elements were associated with secondary products, like iron compounds and organic matter. Time periods investigated were from 2 to 12 hours. For apatite, observations have shown the increasing dissolution of grains, that confirms reactions and the strong association of P with organic aggregates after the process, according to prior results. No crystallline new phases have been identified, although some bicalcic phosphate and other new phases may be present. These observations are reflected in the improved P solubility data with water, citric acid 2%, and neutral amonium citrate. This increasing in P solubility has given better agronomic results for 12h Humifert product than other materials (not treated or not mixed with organic matter), showing that Humifert process was capable to release P form apatite and keep it adsorved in organic matter, and then relese for the plants. Even though, this solubility was not enough to reach the level of monocalcic phosphate (FMC, 100% soluble).

O processo Humifert trata material fosfático e orgânico em um reator, com ácido nítrico nascente, para produzir compostos organo -fosfatados cuja solubilidade em P é maior que o material fosfático natural mas menor que os fertilizantes industriais tradicionais. É um processo alternativo de fabricação de fertilizantes que objetiva aproveitar materias fosfáticos de baixo teor ou de difícil tratamento industrial, potencialmente descartados, e também materiais orgânicos diversos, dando finalidade, portanto, a rejeitos e diminuindo, assim, os custos econômicos e ambientais das indústrias de fósforo. Além da solubilidade em P, os compostos formados têm a vantagem de conter matéria orgânica, em geral necessária para os solos tropicais. Este trabalho teve como objetivo a colocação em funcionamento rotineiro do reator Humifert, fabricado pela primeira vez no Brasil, a obtenção de compostos organofosfatados a partir do minério fosfático de Angico dos Dias (BA) e de lodo de esgoto, a caracterização dos compostos obtidos a partir de vários procedimentos (difração de raios X, microscopia óptica e eletrônica, análises químicas microlocalizadas, especfotometria de absorção no infravermelho, análises elementar e de solubilidade do P) e a avaliação da eficiência agronômica em casa de vegetação. A pesquisa insere-se num projeto mais amplo que pretende aprofundar o estudo do processo, visando sua futura aplicação em determinadas condições. Os compostos produzidos demonstraram que a fase mineral da mistura rocha fosfática - matéria orgânica sofre ataque químico progressivo, em períodos de tempo investigados de 2h até 12h, e que os elementos químicos liberados deste ataque associa-se aos produtos secundários presentes, como os compostos ferruginosos, e também à matéria orgânica. Particularmente para a apatita, verificou-se consumo crescente dos grãos com o aumento do tempo de exposição ao ataque, confirmando o funcionamento do equipamento e a ocorrência das reações, e, ainda, a forte associação do P com os agregados de matéria orgânica após o processo, confirmando trabalhos anteriores. Não foram identificadas fases cristalinas neoformadas, embora haja a possibilidade de ter havido formação de fosfato bicálcico ou de outros compostos em alguns dos produtos obtidos. Essas observações são refletidas nos resultados de solubilidade com diferentes extratores (água, ácido cítrico a 2% e citrato neutro de amônio), já que a alteração e o consumo da apatita, relacionados à possível formação de compostos mais solúveis e à associação do P com a matéria orgânica, por adsorção, podem ter contribuído para o aumento da solubilidade nos extratores utilizados. O aumento de solubilidade em P permitiu resultados agronômicos melhores, para o composto Humifert de 12h, do que os demais tratamentos (materiais não processados no reator ou não misturados com matéria orgânica), mostrando que foi capaz de disponibilizar o P liberado da apatita e adsorvido pela matéria orgânica às plantas, embora não tenha sido suficiente para eficiência agronômica comparável ao fosfato monocálcico (FMC, com 100% de solublidade). / The Humifert is a French process involving the attack of a mixture of phosphate rock (PR) and organic matter (OM) through the fresh-forming nitric acid, producing organic-phosphatic compounds with P solubility greater than phosphatic rock and lower than traditional fertlizers. This is an alternative process proffiting low-grade or difficult phosphatic materials, potentially discarded, and several organic materials, giving na application to rejects, and decreasing economical na environmental costs of P industries. More than a good P solubility, the formed compounds have organic matter, which is an advantage for tropical soils. The aim os this reserch was install the first Brazilian Humifert reactor, produce Humifert compounds using Angico dos Dias phosphatic ore and sewage sludge, their characterization by several technicals (X ray diffraction, optical and scanning electronic microscopy, chemical analysis, infrared spectroscopy and P solubility evaluation), and agronomic experimentation in the greenhouse. Data characterization and for solubility and agronomic experimentation suggests that increasing attack occurred in mineral phases, and released elements were associated with secondary products, like iron compounds and organic matter. Time periods investigated were from 2 to 12 hours. For apatite, observations have shown the increasing dissolution of grains, that confirms reactions and the strong association of P with organic aggregates after the process, according to prior results. No crystallline new phases have been identified, although some bicalcic phosphate and other new phases may be present. These observations are reflected in the improved P solubility data with water, citric acid 2%, and neutral amonium citrate. This increasing in P solubility has given better agronomic results for 12h Humifert product than other materials (not treated or not mixed with organic matter), showing that Humifert process was capable to release P form apatite and keep it adsorved in organic matter, and then relese for the plants. Even though, this solubility was not enough to reach the level of monocalcic phosphate (FMC, 100% soluble).

Les nanoparticules d'alliage FePt, obtenues dans la phase chimiquement ordonnée L10, présentent un fort intérêt pour la réalisation de média magnétiques à très haute densité de stockage (>1 Tb/in2). Cette thèse concerne l'étude des propriétés structurales et magnétiques de telles nanoparticules synthétisées par voie chimique. L'étude détaillée, structurale et magnétique, de particules de FePt (3-4 nm) met en évidence une structure hétérogène en composition : un coeur riche en Pt (Fe30Pt70) et une surface riche en Fe. Cette structure, obtenue pour plusieurs protocoles de synthèse étudiés, est liée à l'influence des ligands (amine et acide oléiques) sur les vitesses d'incorporation du Fe et du Pt. À partir de cette observation, nous avons mis en oeuvre un nouveau ligand en remplacement de l'amine, le pentadécanenitrile. Nous avons ainsi obtenu des particules de composition plus homogène, et également aptes à l'auto-organisation sur des substrats. Les méthodes de synthèse chimique donnent des particules dans la phase chimiquement désordonnée et des recuits à haute température sont nécessaires pour obtenir la phase L10. Malgré, la présence d'une structure coeur-coquille, la phase L10 est obtenue après un recuit sous vide à 650°C, indiquant que le fer de surface est disponible. Ces recuits s'accompagnent systématiquement d'une forte coalescence des particules. Nous avons donc étudié une voie alternative pour obtenir la phase L10 à des températures modérées : l'irradiation par des ions He+. Les premiers résultats, encourageants, indiquent une homogénéisation de la composition après irradiation des particules à température modérée, ainsi qu'un accroissement de leur aimantation.

Ce manuscrit présente l'utilisation de trifluoro(organo)borates de potassium dans des réactions de formation de liaisons carbone-carbone catalysées par des complexes du rhodium. Ces composés très stables, faciles à préparer et à purifier constituent une alternative intéressante aux dérivés du bore trivalent habituellement utilisés en catalyse. Un système catalytique général a été développé pour réaliser des additions de Michael asymétriques. L'emploi d'une diphosphine chirale assure un bon contrôle de l'énantiosélectivité et de bonnes conversions sont obtenues en milieu neutre sans ajout d'un large excès d'organométallique. Une nouvelle méthode catalytique d'addition-1,2 a permis d'obtenir des alcools dans des conditions très douces. Cette réaction très générale peut être appliquée à la synthèse de carbinols diversement substitués. Enfin, une réaction de couplage entre un aldéhyde et un organométallique a été découverte. L'activation formelle d'une liaison C-H permet ainsi un accès facile à de nombreuses cétones non symétriques à partir de dérivés peu fonctionnalisés.

In this work mesoporous organisilica materials are synthesized through the silica sol-gel process. For this a new class of precursors which are also surfactant are synthesized and self-assembled. This leads to a high surface area functionality which is analysized with copper (II) and water adsorption. / Im Rahmen dieser Arbeit werden mesoporöse Amin-funktionalisierte Organo-Silikate durch den Silika Sol-Gel Prozess hergestellt. Dabei werden neue Alkoxysilyl-Precursoren synthetisiert und condensiert die die gewünschte Funktion auf die Oberfläche dirigieren. Herstellt werden primäre, secundäre und chirale Amine. Die Oberflächenfunktionalität wird mit Kupfer (II) und Wasser Adsorption analysiert.