Powerful tools have emerged in the past few years to allow the sensing, imaging and modulation of biological processes in living systems. Bioorthogonal organometallic reactions are transformations catalysed by transition metals, which are compatible within a biological environment. Palladium-mediated cross-coupling and decaging reactions, for example, have been successfully applied to catalyse non-natural chemical transformations within a biological milieu. Up until now, copper-catalysed cycloaddition reactions have been used extensively for the conjugation, immobilisation, and purification of biomolecules, but their further application in vivo has been limited by the inherent toxicity of copper. Herein, different transition metal catalysts were designed and applied in cellular and in vivo manipulations. Polymeric solid supports were functionalised with palladium nanoparticles and used as biocompatible, heterogeneous catalysts in selective decaging and cross-coupling reactions to activate fluorescent probes and synthesise cytotoxic anticancer drugs in situ. In order to gain tumour selectively, targeting functionalities were incorporated into the particles to allow the spatial control of the selective activation of labelling probes. The simultaneous synthesis of two different anticancer agents intracellularly, by two totally different mechanisms (in situ synthesis and decaging), is reported. The cellular toxicity of copper was addressed by entrapping copper nanoparticles on a polymeric solid support, allowing the activation of labelling probes, as well as the synthesis of an anticancer agent from two benign components through the well-known copper catalysed azide-alkyne cycloaddition. The biocompatibility of the copper catalysts in vivo was shown by implantation in zebrafish embryos.

The invention of catalytic processes that convert feedstock chemicals into pharmacologically-privileged amines is a landmark challenge in organic synthesis. This thesis describes the development of three novel transition-metal catalyzed processes for the synthesis of alkylamines that attempts to meet this challenge. The first Pd-catalyzed methylene β-C−H carbonylation of alkylamines to form substituted β-lactams is reported. Through the synergistic use of a Pd-catalyst and Xanpthos ligand, secondary amines underwent exclusive methylene β-C−H activation in high yields and diastereoselectivities. Subsequently, the development of a remarkably selective methylene β-C−H carbonylation of α-tertiary amines (ATAs), is detailed. This methodology enables the C−H carbonylation of methylene C−H bonds over traditionally more reactive methyl and C(sp2)−H bonds. Importantly, a range of functional groups previously incompatible with C−H technologies were tolerated in good yields. Finally, the development of a novel multicomponent synthesis of tertiary amines is described. The novel photocatalytic single-electron reduction of alkyl iminium ions furnishes -amino radicals that engage alkenes forming a new C-C bond. The reaction exhibits broad functional group tolerance and enables the synthesis of amines not readily accessible by existing methods.

Desde a descoberta da cisplatina várias tentativas têm sido feitas com o objetivo de desenvolver novos quimioterápicos com menor toxicidade e efeitos colaterais melhorados para tratar o câncer. Complexos de coordenação com metais de transição variados vêm sendo estudados buscando melhoras na biodisponibilidade, seletividade e efeitos adversos. Neste sentido, o presente trabalho consiste na síntese e caracterização estrutural de complexos de PdII e PtII com ligantes derivados de tiossemicarbazidas contendo o grupo fluoróforo pireno visando a obtenção de potenciais agentes antitumorais. Os agentes quelantes foram preparados a partir de reações de condensação entre o pirenocarboxaldeído e a tiossemicarbazida desejada resultando em compostos 1-pirenocarboxaldeído-N(3)-R-tiossemicarbazona, H2PrR, onde R = etil ou ciclohexil, Pr = pireno. A partir dos ligantes H2PrR foram realizadas as reações de complexação com os íons metálicos PdII e PtII, sendo possível obter duas classes de complexos com diferentes características: complexos monoméricos contendo ligantes clorido e trifenilfosfano do tipo [MCl(PPh3)(HPrR)] e complexos tetraméricos do tipo [M4(μ-S-PrR-κ3-C,N,S)4], onde M = PdII ou PtII, R = etil ou ciclohexil. Nas duas primeiras séries, o grupo R foi modificado por etil e ciclohexil para investigar a correlação entre lipoficilidade e atividade antiproliferativa, enquanto que o grupamento pireno foi incluído pensando que um maior número de unidades aromáticas possivelmente melhoraria a intercalação com o DNA e/ou ser utilizado como um marcador celular. A caracterização dos complexos envolveu técnicas como: análise elementar, espectroscopia na região do infravermelho e do UV-Vis, condutimetria, ressonância magnética nuclear (1H e 13C RMN) e difração de raios X em monocristal. As análises mostraram que os agentes complexantes podem atuar em diferentes modos coordenação tanto com relação à denticidade quanto à carga. A atividade antiproliferativa dos novos compostos de PdII e PtII foi determinada, sendo que vários deles apresentaram IC50 promissores contra células de câncer de ovário e, em muitos casos, as atividades observadas foram melhores do que a da cisplatina. Os dados obtidos indicam efeitos diferentes nos resultados de atividade biológica para os centros metálicos (Pd vs Pt) e ligantes utilizados (Etil vs Ciclohexil). Estudos de captação e distribuição celular mostraram que o complexo [PdCl(PPh3)(HPrCh)] atinge o núcleo celular. Com o intuito de verificar possíveis alvos biológicos, testes de interação com o DNA, ciclo celular e inibição da enzima Top IB foram realizados para os compostos. Os resultados do ciclo celular, mostraram uma maior inibição nos estádios S e G2/M para os complexos do tipo [PdCl(PPh3)(HPrR)]. Diante dos resultados obtidos, verificou-se que a Top IB é um dos alvos moleculares para os complexos do tipo [MCl(PPh3)(HPrR)], um mecanismo diferente da cisplatina. Estes resultados preliminares são bastante promissores e mostram que alguns dos complexos estudados neste trabalho apresentam-se como potenciais agentes para serem usados na terapia do câncer em combinação com os demais fármacos em uso clínico. / Since the discovery of cisplatin, many attepemts have been made to prepare new drugs with less cytotoxicity and side effects. Coordination complexes based on a variety of transition metals have been developed in the search for improved bioavailability, selectivity and reduced adverse side-effects. This work consists on the synthesis and structural characterization of PdII and PtII complexes with chelating compounds derived from thiosemicarbazides containing the pyrene fluorophore group aiming to obtain potential antitumor compounds. The chelating agents were prepared from condensation reactions between the pyrenocarboxaldehyde and the desired thiosemicarbazide resulting in 1-pyrenocarboxaldehyde-N (3) -R-thiosemicarbazone compounds, H2PrR, where R = ethyl or cyclohexyl. Complexation reactions with the metal ions PdII and PtII were carried out with the H2PrR ligands. It was possible to obtain two main classes of complexes with different characteristics: i) monomeric complexes containing chlorido and triphenylphosphane ligands of the type [MCl(PPh3)(HPrR)] and (ii) tetramer complexes of the type [{M(PrR)}4], where M = PdII or PtII and R = etyl ou cyclohexyl. In both series the R group was modified by ethyl and cyclohexyl in order to investigate the correlation between lipophilicity and antiproliferative activity, while the pyrene group was attached to the ligands with the belief that a higher number of aromatic units would improve DNA intercalation and/or to be used as an intracellular probe. The characterization of the complexes involved techniques such as: elemental analysis, infrared and UV-Vis spectroscopy, conductimetry, nuclear magnetic resonance (1H and 13C NMR) and single crystal X-ray diffraction. The antiproliferative activity of the novel PdII and PtII compounds have been determined, several of them showed promising IC50 against ovarian cancer cells, and in many cases the observed activities are better than that of cisplatin. The data obtained indicate different effects for the metal centers (Pd vs Pt) and the ligands used (ethyl vs cyclohexyl). Uptake and cellular distribution studies proved that the palladium complex [PdCl(PPh3)(HPrCh)] achieved the cell nucleus. In order to verify possible biological targets, interaction with DNA, cell cycle and inhibition experiments of the topoisomerase IB (Top IB) enzyme were performed for some compounds. Cell cycle results showed an inhibition at the S and G2/M stages for the complexes [PdCl(PPh3)(HPrR)]. Overall, the results indicated the Top IB enzyme as one of the targets of the complexes. These preliminary results are quite promising and show that some of the complexes studied here can be used in cancer therapy in combination with other anticancer drugs.

O paládio é um dos elementos do grupo da platina presente em baixos teores na natureza. Nos últimos anos com o crescente uso deste elemento nos catalisadores automotivos e nas investigações para o desenvolvimento de drogas anti-tumorais, as suas determinações tornaram-se de grande interesse. No presente trabalho foi feito um estudo sobre a determinação de paládio em amostras biológicas e materiais de referência pelo método de análise por ativação puramente instrumental com nêutrons térmicos (INAA) e epitérmicos (ENAA) separadamente, bem como pela ENAA após separação do paládio por meio das técnicas de extração com solventes e de extração em uma coluna de fase sólida. As amostras analisadas no presente estudo foram: material de referência BCR 723 – Palladium, Platinum and Rhodium in road dust, material catalisador automotivo do teste de proficiência do CCQM-P63 e amostras de tecido bovino contendo Pd preparadas no laboratório. As irradiações das amostras e padrão para INAA e ENAA foram realizadas no reator IEA-R1 sob fluxo de nêutrons térmicos da ordem de 4 x 10 12 n cm-2 s-1 e por um período de 4 h nas irradiações térmicas e de 16 h nas epitérmicas. Depois de adequados tempos de decaimento as medições das atividades gama induzidas das amostras e padrões foram feitas usando um espectrômetro de raios gama constituído de um detector de Ge hiperpuro e eletrônica associada. A concentração de paládio foi calculada pelo método comparativo. O paládio foi medido pelo pico de 88,0 keV do 109Pd localizado numa região do espectro de baixa energia onde ocorre a interferência de picos de raios X, da radiação de freiamento e do efeito Compton do 24Na. A pré-separação do paládio dos elementos interferentes pelo método de extração com solventes foi feita por meio da extração do complexo formado entre o paládio e a dimetilglioxima em clorofórmio. O método de separação por meio da extração em fase sólida consistiu na retenção do paládio em uma coluna de fase sólida de octadecilsilano, contendo complexante N,N-dietil-N’-benzoil tiouréia (DEBT) adsorvido e em seguida fazendo a eluição de paládio com etanol. Alíquotas das soluções resultantes da préseparação, livres de elementos interferentes, foram pipetadas em cápsulas de polietileno e submetidas à ENAA. A comparação entre os resultados de paládio obtidos por diferentes procedimentos de ativação com nêutrons indicou uma boa concordância e uma boa precisão com desvios padrão relativos variando de 2 a 14%. Os rendimentos de recuperação na pré-separação de paládio variaram de 70,9 a 97,7 % e estes resultados dependem do tipo de matriz e da técnica de pré-separação aplicada. Os valores de limite de detecção obtidos para análise do tecido muscular bovino foram de 11,0 e 0,4 μg g-1 pelos métodos de INAA e ENAA, respectivamente. Para o caso do material de referência BCR-723 foram obtidos limites de 24,0 e 1,7 μg g-1, respectivamente na INAA e ENAA e estes resultados indicaram que o limite de detecção depende do tipo de matriz analisada. A irradiação com nêutrons epitérmicos permitiu aumento da sensibilidade devido à redução do problema de interferência e além disso a aplicação da separação prévia do paládio seguida de ENAA proporcionou um aumento da sensibilidade quando comparada com ENAA purament e instrumental. / Palladium is one of platinum group elements present in the nature at very low concentrations. However with the use of this element in the automobile catalyzers Pd became a new pollutant. Besides, Pd has been studied in the preparation of new antitumour drugs. Consequently, there is a need to determine Pd concentrations in biological and environmental samples. This study presents palladium results obtained in the analysis of biological samples and reference materials using instrumental thermal and epithermal neutron activation analysis (INAA and ENAA). The solvent extraction and solid phase extraction separation methods were also applied before ENAA. The samples analyzed in this study were, reference material BCR 723–Palladium, Platinium and Rhodium in road dust, CCQM-P63 automotive catalyst material of the Proficiency Test and bovine tissue samples containing palladium prepared in the laboratory. Samples and palladium synthetic standard were irradiated at the IEA-R1 nuclear research reactor under thermal neutron flux of about 4 x 10 12 n cm-2 s-1, during a period of 4 and 16 h for INAA and ENAA, respectively. The induced gamma activity of 109Pd to the sample and standard was measured using a hyperpure Ge detector coupled to a gamma ray spectrometer. The palladium concentration was calculated by comparative method. The gamma ray energy of 109Pd radioisotope measured was of 88.0 keV, located in a spectrum region of low energy where occurs the interference of X rays, “bremsstrahlung" radiations, as well as Compton effect of 24Na. The pre-separation of palladium from interfering elements by solvent extraction was performed using dimethylglyoxime complexant and chloroform as diluent. In the case of the pre separation procedure using solid reversed phase column, the palladium was retained using N,N-diethyl-N’-benzoyl thiourea complexant and eluted using ethanol. Aliquots of the resulting solutions from the pre-separations, free of interfering elements, were transfered to polyethylene capsules and analyzed by ENAA. Comparisons of palladium results obtained using different procedures of neutron activations analysis showed good agreement and precision. The relative standard deviations of palladium results varied between 2 and 14 %. The recovery yields obtained in the pre-separation procedure varied from 70.9 to 97.7 %, depending on the matrices analyzed and method of separation. Detection limits of 11.0 and 0.4 μg g-1 were obtained in the Pd determination in bovine muscle samples by INAA and ENAA, respectively. For reference material BCR- 723 road dust detection limits of 24.0 and 1.7 μg g-1 were obtained by INAA and ENAA, respectively. These results indicated that the detection limit depends on the matrix type to be analyzed and the epithermal neutron activation allowed high sensitivity for Pd determination due to the reduction of interferences. In regards to palladium determination using pre-separation procedures, the detection limit values indicated that the extraction procedure provides higher sensitivity, when compared to purely instrumental ENAA.

Two experiments have been conducted to ascertain if a cell with a palladium cathode, a platinum anode, and a solution of H2SO4 in D2O can produce excess heat under electrolysis compared to a similar cell with H2O. In each experiment, two cells were connected in series with constant current. The two cells were identical except for the fact that the heavy water cell used D2O instead of H2O in the electrolyte. Both cells in each experiment employed Pd cathodes, Pt anodes, and H2SO4 in the solution. On a piece of Pd foil that had been cold-rolled and cleaned like the cathodes but had not been electrolyzed, scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) failed to find any traces of unexpected elements. In the first experiment the indication was that the light water cell was slightly warmer despite receiving slightly less power. Small amounts of silver were found on both cathodes after electrolysis. In the second experiment, the D2O cell produced an excess heat relative to the H2O cell that was too large by at least an order of magnitude to be explainable by chemical reactions or mechanical artifacts. After electrolysis, it was found that Cd was present on the surface of the H2O cathode at levels of concentration that were variable but generally no less than 4% relative to Pd (above 3σ). The H2O cathode of this second experiment finished electrolysis very straight. The D2O cell cathode finished severely arched (~30o), with its convex side facing the anode, and covered in a deposit of powdery black substance which was most likely PdS formed accidentally on the first day of this experiment when the D2O cell had been run with the wrong polarity. On this D2O cell cathode, no statistically significant traces of Cd were detected but Ag was present in 2-5% concentration relative to Pd. In some spots, the Ag abundance surpassed 20% that of Pd. The most likely explanation is neutron-induced nuclear transmutation of some of the Pd nuclides with direct release of heat into the solid-state lattice.

Recently, there has been growing interest in using transition metals (TM) for catalytic and electromagnetic applications, due to the ability of TMs to form stable compounds in multiple oxidation states. In this research, the focus has been on the synthesis and characterization of carbon-supported TM nanoparticles (NPs), specifically palladium (Pd) and gold (Au) NPs, for catalytic applications, and transition metal oxides (TMO) NPs, specifically Fe3O4 NPs for electromagnetic applications. Carbon supports have several advantages, such as enabling even distribution of particles, offering large specific surface area with excellent electron conductivity, and relative chemical inertness. In this dissertation, for catalytic applications, emphasis was on removal of trichloroethylene (TCE) from groundwater. For this application, carbon-supported Pd/Au NP catalysts were developed. Pd was chosen because it is more active, stable and selective for desired end-products, and Au has shown to be a good promotor of Pd's catalytic activity. Often, commercially available Pd-based catalysts are made using harsh chemicals, which can be harmful to the environment. Here, an environmentally friendly process with aspects of green chemistry was developed to produce carbon-supported Pd/Au NP catalysts. This process uses a combination of sonochemistry and solvothermal syntheses. The carefully designed carbon-supported Pd/Au NP catalyst material was systematically characterized, tested against TCE, and optimized for increased rate of removal of TCE. Electron microscopy and spectroscopy techniques were used to study the material including structure, configuration and oxidative state. The Pd/Au NPs were found mainly to form clusters with an aggregate-PdShellAuCore structure. Using state-of-the-art direct detection with electron energy loss spectroscopy, the Pd NPs were found to have an oxidative state of zero (0). The formation of the catalyst material was studied in detail by varying several synthesis parameters including type of solvent, sonication time, synthesis temperature etc. The most optimized catalyst was found remove TCE at double the rate of corresponding commercial Pd-based catalysts in a hydrogen headspace. This material was found to catalyze the removal of TCE via traditional hydrodehalogenation and shows promise for the removal of other contaminants such as trichloropropane (TCP), carbon tetrachloride (CT). This green approach to make and optimize TM materials for specific applications was extended to TMOs, specifically magnetite (Fe3O4) and further developed for the application of electromagnetism. As catalysts, Fe3O4 is used for removal of p-nitrophenol from water. However, since the carbon-supported Pd/Au material system was developed and optimized for catalysis, here, carbon-supported Fe3O4 NPs were developed for electromagnetic applications. There has been growing interest in tuning the magnetic properties of materials at room temperature with the use of external electric fields, for long-term applications in data storage and spintronic devices. While a complete reversible change of material properties has not yet been achieved, some success in partial switching has been achieved using multiferroic spinel structures such as Fe3O4. These materials experience a change in magnetic moment at room temperature when exposed to the electric fields generated by electrochemical cells such as lithium ion batteries (LIBs) and supercapacitors (SC). In the past, a 1% reversible change was observed in Fe3O4 using LIBs. Here, building on the developments from previous material system, Fe3O4 NPs were directly hybridized onto the graphene support in order to increase the observable change in magnetic moment. The material was systematically designed and tested for this application, including a study of the material formation. A simple, environmentally friendly synthesis using the solvothermal process was implemented to make the graphene-supported Fe3O4 NPs. This new material was found to produce a reversible change of up to 18% in a LIB. In order to overcome some of the difficulties of testing with a LIB, a corresponding hybrid SC was designed, built and calibrated. The graphene-supported Fe3O4 NPs were found to produce a net 2% reversibility in the SC, which has not been reported before. The results from both the LIB and SC were analyzed to better understand the mechanism of switching in a spinel ferrite such as Fe3O4, which can help optimize the material for future applications. The focus of this dissertation was on the development of a methodology for carbon-supported TM and TMO NPs for specific applications. It is envisioned that this approach and strategy will contribute towards the future optimization of similar material systems for a multitude of applications.

This thesis addresses the design and use of suitable nanomaterials and surface acoustic wave sensors for hydrogen detection and sensing. Nanotechnology is aimed at design and synthesis of novel nanoscale materials. These materials could find uses in the design of optical, biomedical and electronic devices. One such example of a nanoscale biological system is a virus. Viruses have been given a lot of attention for assembly of nanoelectronic materials. The tobacco mosaic virus (TMV) used in this research represents an inexpensive and renewable biotemplate that can be easily functionalized for the synthesis of nanomaterials. Strains of this virus have been previously coated with metals, silica or semiconductor materials with potential applications in the assembly of nanostructures and nanoelectronic circuits. Carbon nanotubes are another set of well-characterized nanoscale materials which have been widely investigated to put their physical and chemical properties to use in design of transistors, gas sensors, hydrogen storage cells, etc. Palladium is a well-known material for detection of hydrogen. The processes of absorption and desorption are known to be reversible and are known to produce changes in density, elastic properties and conductivity of the film. Despite these advantages, palladium films are known to suffer from problems of peeling and cracking in hydrogen sensor applications. They are also required to be cycled for a few times with hydrogen before they give reproducible responses. The work presented in this thesis, takes concepts from previous hydrogen sensing techniques and applies them to two nanoengineered particles (Pd coated TMV and Pd coated SWNTs) as SAW resonator sensing materials. Possible sensing enhancements to be gained by using these nanomaterial sensing layers are investigated. SAW resonators were coated with these two different nano-structured sensing layers (Pd-TMV and Pd-SWNT) which produced differently useful hydrogen sensor responses. The Pd-TMV coated resonator responded to hydrogen with nearly constant increases in frequency as compared to the Pd-SWNT coated device, which responded with concentration-dependent decreases in frequency of greater magnitude upon hydrogen exposure. The former behavior is more associated with acousto-electric phenomena in SAW devices and the later with mass loading. The 99% response times were 30-40 seconds for the Pd-TMV sensing layer and approximately 150 seconds for the Pd-SWNT layer. Both the films showed high robustness and reversibility at room temperature. When the Pd film was exposed to hydrogen it was observed that it produced decreases in frequency to hydrogen challenges, conforming to mass loading effect. It was also observed that the Pd film started degrading with repeated exposure to hydrogen, with shifts after each exposure going smaller and smaller.

Catalisadores de ouro tem despertado bastante interesse nos últimos anos devido à elevada seletividade apresentada na hidrogenação de moléculas multifuncionais, proporcionando assim uma síntese química mais limpa. No entanto, esses catalisadores exibem uma atividade muito menor do que os metais do grupo VIII, devido à sua capacidade limitada de dissociar H2. O paládio tem sido frequentemente combinado ao ouro para atuar em reações de hidrogenações catalíticas, devido à sua elevada capacidade de adsorver e dissociar o hidrogênio molecular, resultando em catalisadores bimetálicos AuPd que muitas vezes apresentam desempenhos catalíticos superiores aos seus homólogos monometálicos. Neste trabalho, foi estudada a ativação de nanopartículas de ouro para reações de hidrogenação pela adição de paládio, considerando a influência de ligantes estabilizantes presentes na superfície do ouro. Os catalisadores monometálicos Auw/TiO2 e Au/TiO2 foram sintetizados através da imobilização de nanopartículas pré-formadas na ausência e presença de excesso de estabilizantes (oleilamina ou hexilamina) provenientes da síntese, respectivamente. Seguindo o mesmo princípio também foram obtidos monometálicos Pd/TiO2. Catalisadores bimetálicos Auw@Pdx/TiO2 e Au@Pdx/TiO2 foram obtidos através da adição de quantidades crescentes de Pd sobre os monometálicos de ouro. Os catalisadores monometálicos apresentaram desempenhos catalíticos inferiores aos respectivos bimetálicos. Estudos iniciais na reação de hidrogenação de ciclohexeno foram fundamentais para compreender a influência da composição e do estabilizantes nas diferentes reações de hidrogenação nas quais os materiais foram aplicados. Os catalisadores livres de ligantes se mostraram ativos nesta reação, Auw@Pdx/TiO2, sendo observado um aumento da atividade à medida que a quantidade de paládio se tornava crescente, alcançando um máximo com 20% de Pd (Auw@Pd0,2/TiO2), seguida de uma diminuição da atividade com a adição de porcentagens maiores. Assim, concluiu-se que a presença de sítios de Au e Pd, além da ausência de excesso de ligantes na superfície, são significativamente importantes para tornar ativos os catalisadores Auw@Pdx/TiO2. Os catalisadores bimetálicos com ligantes na superfície, que apresentaram pior desempenho na hidrogenação de alquenos, mostraram-se promissores na semi-hidrogenação de alquinos. O catalisador contendo 1% de Pd (Au@Pd0,01/TiO2), ao ser empregado na hidrogenação de fenilacetileno, apresentou 100% de conversão e seletividades a estireno > 90%. Ao serem adicionadas porcentagens de Pd ≥ 3%, a seletividade a estireno diminui significativamente. Esta também foi alterada ao variar a quantidade de ligante (alquilamina) na superfície do catalisador bimetálico e independe do tamanho da cadeia orgânica do ligante empregado. Finalmente, podemos concluir que sistemas catalíticos altamente ativos e seletivos podem ser obtidos controlando a quantidade de paládio adicionado ao ouro, mas a presença de ligantes estabilizantes também tem influência e não pode ser negligenciada. / Over the past few years, gold catalysts have aroused great interest among researchers due to an enhanced selectivity exhibited in the hydrogenation of multifunctional molecules, enabling greener chemical synthesis. Nevertheless, since gold has a very limited ability to dissociate molecular hydrogen, these catalysts show lower activity compared to group VIII metals. Palladium has been widely used in combination with gold in catalytic hydrogenations; due to its high ability to adsorb and dissociate molecular hydrogen, the resulting bimetallic AuPd systems often show superior performance over their monometallic counterparts. The present work embodies studies on the activation of gold nanoparticles for hydrogenation reactions by adding increasing amount of palladium, considering the influence of capping ligands on the activity and selectivity exhibited by the bimetallic Au@Pd catalysts. The monometallic Auw/TiO2 and Au/TiO2 catalysts were prepared via immobilization of preformed nanoparticles in the absence and presence of excess stabilizers (oleylamine and hexylamine) used in the synthesis, respectively. Monometallic Pd/TiO2 was also synthesized following the same principle. Bimetallic catalysts Auw@Pdx/TiO2 e Au@Pdx/TiO2 were obtained by the addition of increasing amounts of Pd on the gold monometallic catalyst. The monometallic catalysts presented lower catalytic performances than the respective bimetallics. Initial studies of cyclohexene hydrogenation were instrumental to understand the influence of the composition and the presence of stabilizers in different hydrogenation reactions where the material were applied. Ligand-free catalysts were active in this reaction, Auw@Pdx/ TiO2, and an increase in activity was observed as the amount of palladium increased, reaching a maximum at 20% Pd (Auw@Pd0.2/TiO2), followed by a decrease in activity with the addition of larger percentages. Thus, it was concluded that the presence of Au and Pd sites, in addition to the absence of excess capping ligands, are significantly important in making the catalysts active. Bimetallic catalysts containing capping ligands, which presented worse performance in the hydrogenation of alkenes, showed promising results in the semi-hydrogenation of alkynes. The catalyst containing 1 wt% Pd (Au@Pd0.01/TiO2), when used in the hydrogenation of phenylacetylene, reached 100% conversion and > 90% selectivity to styrene. When percentages of Pd ≥ 3 wt% were added, the selectivity to styrene decreases significantly. Selectivity was also altered by varying the amount of ligand (alkylamine) on the surface of the bimetallic catalyst and regardless the size of the organic chain. Finally, we can conclude that highly active and selective catalytic systems can be obtained by controlling the amount of added palladium on gold, but the presence of capping ligands is also importante and can not be neglected.

Four tumour active trinuclear complexes: DH4Cl: [{trans-PtCl(NH3)2}2m-{trans-Pd( NH3)2(H2N(CH2)4NH2)2]Cl4, DH5Cl: [{trans-PtCl(NH3)2}2m-{trans-Pd( NH3)2(H2N(CH2)5NH2)2]Cl4, DH6Cl: [{trans-PtCl(NH3)2}2m-{trans-Pd( NH3)2(H2N(CH2)6NH2)2]Cl4, DH7Cl: [{trans-PtCl(NH3)2}2m-{trans-Pd(NH3)2-( H2N(CH2)7NH2)2]Cl4 and one dinuclear complex DHD: [{trans-PtCl(NH3)2}�-{ H2N(CH2)6NH2}{trans-PdCl(NH3)2]Cl(NO3), have been prepared and characterised based on elemental analyses, IR, Raman, mass and 1 H NMR spectral measurements. For the trinuclear complexes, the synthesis has been carried out using a step-up method branching out from the central palladium unit. A purity of about 95% has been obtained by repeated dissolution and precipitation. The activity against human cancer cell lines including ovary cell lines: A2780, A2780 cisR , A2780 ZD0473R , non small lung cell line: NCI-H640 and melanoma: Me-10538 have been determined based on MMT assay. Cell uptakes, DNA-binding have been determined for ovary cell lines: A2780, A2780 cisR . The nature of interaction with pBR322 plasmid DNA and ssDNA has been studied for trinuclear complexes DH4Cl, DH5Cl, DH6Cl and DH7Cl and the dinuclear complex DHD. Interaction of DH6Cl with adenine and guanine has also been studied by HPLC. The compounds are found to exhibit significant anticancer activity against cancer cell lines especially ovarian cancer cell lines: A2780, A2780 cisR and A2780 ZD0473R . DH6Cl in which the linking diamine has six carbon atoms is found to be the most active compound. As the number of carbon atoms in thelinking diamine is changed from the optimum value of six, the activity is found to decrease, illustrating the structure-activity relationship. The increase in uptake of the trinuclear complexes in A2780 cell line with the increase in size of the linking diamine coupled with the low molar conductivity values found for the solutions of the compounds suggest that the compounds would remain in solution as undissociated �molecules� and hence could cross the cell membrane by passive diffusion. Much lower resistance factors for the all the multinuclear compounds including DHD as applied to A2780 cisR cell line, as compared to that for cisplatin, suggest that the compounds are able to overcome multiple mechanisms of resistance operating in the cell line. All of the multinuclear complexes are expected to form long-range interstrand GG adducts with DNA, causing irreversible global changes in the DNA conformation but unlike cisplatin do not cause sufficient DNA bending to be recognized by HMG 1 protein. Increasing prevention of BamH1 digestion with the increase in concentration of the multinuclear compounds also provide support to the idea that the compounds because of the formation of a plethora of interstrand GG adducts are able to cause irreversible changes in DNA conformation. The results of the study show that indeed new trinuclear tumour active compounds can be found by replacing the central platinum unit in BBR3464 with other suitable metal units.

Depuis ces vingt dernières années, les nanotechnologies représentent une aire de recherche en plein développement. En particulier, les nanoparticules métalliques ont suscité un intérêt croissant en catalyse de part leurs propriétés intermédiaires entre les catalyseurs homogènes et hétérogènes classiques. Ainsi, leur réactivité de surface peut entrainer de nouvelles sélectivités lors des synthèses de molécules d'intérêt médical, pharmaceutique ou agrochimique. Au cours de cette thèse, une nouvelle famille de ligands chiraux polyfonctionnels dérivés du 9,10-dihydroanthracène, pour la stabilisation de nanoparticules de palladium, a été synthétisée. Les colloïdes ont été obtenus par décomposition de précurseurs organométalliques en présence de ces nouveaux ligands. Les particules de taille, de forme et de composition chimique contrôlées ont été utilisées en réaction de couplage C-C de Suzuki. Ces réactions ont été réalisées en milieux organique et liquide ionique. Aussi, la réactivité de surface a été étudiée dans l'hydrogénation et la dismutation du 1,4-cyclohexadiène. Dans l'objectif d'étudier la chimie de coordination des ligands, des complexes de palladium ont été synthétisés et complètement caractérisés. L'induction asymétrique apportée par ces ligands optiquement purs a été estimée dans des réactions asymétriques d'alkylation allylique et de couplage C-C de Suzuki.