Ph.D. / This study comprises the preparation and characterization of new carbene complexes of iron, molybdenum, gold, copper and silver from azolyl and thienyl precursors. In addition, the syntheses of aminoacyl chelate and metallacyclic iron compounds as well as unique 6-membered dimeric and 18-membered trimeric thienyl gold compounds are reported. Furthermore, di(vinyl)carbene complexes, which are not yet known for gold and which are very rare for most other metals, are also described. In contrast to most other carbene complexes that result from precursors in which the heteroatom is situated a or y to the coordinated carbon atom, the new amino(organo)-, organo(thio)- and di(organo) carbene complexes are unique in that they have been prepared from azolyl or thienyl precursors in which the nucleophilic heteroatom is located outside the coordinated ring system and is separated from the coordinated carbon by several bonds. The complex [CpFe(CO)2C1] reacts with lithiated pyrazole, (thienyl)oxazoline or (thienyl)pyridine to form precursor pyrazolyl and thienyl iron(II) compounds which upon alkylation or protonation with CF3SO3Me or CF3SO3H afford amino(organo)-, organo(thio)- or heterometallacyclic alkoxy(amino)- and hydroxy(amino)carbene complexes as well as compounds which show pyridinium character. The heterometallacyclic complexes incorporate unusual ferropyridine or ferropyrole rings. ' 3C-{'}I} NAIR data of the above compounds show that the coordinated carbons of the azolyl and thienyl ligands are significantly affected upon carbene formation, although an X-ray crystallographic investigation indicates that carbene formation has little if any effect on bond distances in the azolyl ligand when it becomes a coordinated azolinylidene. The molecular structures of the pyrazolyl complex [CpFe(C0) 2{C=CHCH=NNPh}], the pyrazolinylidene complex [CPFe(C0) 2{CCHHNHI4P11}1[CF3S03], the 2-(2'-oxazolinyl)thien- 5-ylidene complex [CpFe(C0)2{CCHHC(1\1HCMe2CH26)}1[CF3S03] and the heterometallacyclic complex [CpFe(C0){CC(=&CMe 2CH2(5)SCH---9-1)] indicate small variations in iron-carbon distances of 1.981(2), 1.969(5), 1.99(1) and 1.959(7) A. Four equivalents of 2-(4',5'-dihydro-4',4'-dimethy1-2'-oxazolinyl)thien-3-yllithium reacts with the acetate [Mo2(O2CMe)4] to form the stable, neutral, quadruply bonded dimolybdenum complex [Mo2{C=C(6=NCMe2CH26)SCH2CH2} 2(02CMe)2], while 4-methylthiazoly1 lithium reacts with the same acetate to form the unstable, thiazolyl molybdate [Mo 2{6=NCMe—Cfg} 8]4". Reaction of [AuCI(tht)] (tetrahydrothiophene) with 2-(4',5'-dihydro-4',4'-dimethy1-2'-oxazoliny1)- thien-3-yllithium or 2-(4',5'-dihydro-4',4'-dimethy1-2'-oxazolinyl)thien-5-yllithium afforded dimeric and trimeric thienyl oligomers of gold(I). The molecular structure of the six-membered dimeric compound [Au{C=C(=NCMe 2CH2O)SCH=CH}li shows a Au...Au separation of 2.8450(6)A, while such interactions are absent in the trimeric compound [Au{C=C(C=NCMe2CH2O)SCH=CH}] 3 . Protonation of the former compound as well as the stable monomers obtained from [Au(tht)C 6F5] or [Au(Cl)PPh 3J afforded unique di(vinyl)carbene as well as imine complexes. Reaction of 2-(2'-pyridyl)thien-5-yllithium with [Au(COPPh 3] and subsequent alkylation yields an organo(thio)carbene compound. Finally, a series of cationic copper(I) bis(carbene) complexes were formed upon sequential treatment of copper(I) trifluoromethanesulfonate with thiazolyl- or pyrazolyllithium and CF3SO3Me. A similar reaction with 4-methylthiazol-2-yllithium and silver triflate produced the first amino(thio)carbene complex of silver.

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In this study, reversed phase HPLC with dual UV photodiode (PDA) and fluorescence (FL) detection were used to investigate copper complexes with fulvic, caffeic, vanillic, salicylic, and adipic acids. Application of the RE method provided valuable information on the retention behavior and spectral characteristics of FA and model compounds. Even though the method was only applicable to VA, the use of the PDA detector allowed the UV-V is scanning of the separated peaks. This allowed the comparison between the UV-Vis spectra of uncomplexed species. The overall results provide an experimental framework for validation of the proposed Cu-humate interaction models.

The work described herein focuses on the synthesis and characterisation of copper(I) complexes bearing N-heterocyclic carbene (NHC) ligands, their use in catalysis as well as organometallic synthesis and related reaction mechanisms. Two classes of complexes were considered: neutral NHC-Cu(I) species and their cationic analogues. Concerning the former, initial efforts were focused on the development of a general and straightforward synthetic methodology towards complexes of the type [Cu(X)(NHC)] (X = Cl, Br, I). More than 10 NHC-Cu(I) species were synthesised in high yields under mild conditions, in air and using technical grade solvents. These complexes exhibited interesting activity in the catalytic dehydrogenation of formic acid/amine adducts proving in three times more efficiency than the copper salts previously employed in such a reaction. Hydroxide- and tert-butoxide analogues showed to be efficient catalysts in the N-methylation of amines with CO₂ as carbon source, and in the dehydrogenative coupling of silanes and carboxylic acids. Experimental and computational work were carried out in order to elucidate the mechanism of these transformations. Regarding the use of these species in organometallic synthesis, homo- and heteroleptic bis-NHC-Cu(I) complexes were employed as carbene transfer reagents to other transition metals. Aside from well-known cationic gold(I) species, two novel palladium(II) analogues were isolated and fully characterised.

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Copper oxides are currently being implemented in various sectors ranging from agriculture to the industry of the electronic components. Due to their structural, optical and electrical properties copper oxides have been studied in several areas such as solar cells, semiconductor materials and cathodes of lithium ion batteries. This fact demonstrates this material is very versatile. In this work copper oxides films were deposited by spray pyrolysis technique using the method of sucrose. This method consists on use of solution, which sucrose is the chelating agent. The parameters of synthesis and deposition were controlled for depositing both copper (I) and copper (II) oxides. They play an important role in influencing the physical properties of the films mainly by changing of the sucrose concentration and temperature of deposition of the film. Measurements of X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrical measure for determining the structural, morphological and electrical properties were carried out. The results shows nanostructured films were grown and the phases can be controlled as much changing the parameter depositions (temperature) as changing the sucrose concentration. It was carried out a heat treatment on the samples in order to analyze the influence of heating on the physical properties. / Os Óxidos de cobre estão atualmente sendo implementados em vários setores, que vão desde a agricultura até a indústria de componentes eletrônicos. Devido às suas propriedades estruturais, ópticas e elétricas, os óxidos de cobre têm sido alvos de pesquisas em várias áreas, tais como células solares, materiais semicondutores e cátodos de baterias de íon de lítio, este fato demonstra ser um material muito versátil. Neste trabalho, filmes de óxidos de cobre, foram depositadas pela técnica spray pirólise, usando o método da sacarose para produção da solução precursora. Este método consiste na utilização de uma solução precursora cuja sacarose tem a função de agente quelante. Os parâmetros de síntese e deposição foram controlados para depositar filmes de óxidos de cobre (I) e óxidos de cobre (II). Estes parâmetros desempenham um papel importante na influencia das propriedades físicas dos filmes, principalmente por alterar a concentração de sacarose e a temperatura de deposição dos filmes. Medidas de difração de raios-X (DRX), microscopia eletrônica de varredura (MEV) e duas pontas foram realizadas para determinar as propriedades estruturais, morfológicas e elétricas. Os resultados mostram filmes nanoestruturados e as fases podem ser controladas tanto pela alteração da temperatura de deposições quanto pela concentração de sacarose. Foi efetuado um tratamento térmico nas amostras, a fim de analisar a influência do aquecimento sobre as propriedades físicas.