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This thesis describes the synthesis and characterisation of a variety of acetylide-bridged di- and trinuclear ruthenium acetylide complexes that were prepared in a controlled fashion, and the preparation and characterisation of the ruthenium(II) complexes required for these stepwise reactions. These precursor complexes, or building blocks, include dimethyl-, acetylidomethyl-, and bis(acetylido)ruthenium(II) complexes. An introduction to metal acetylide chemistry is presented in Chapter 1. The previous research in this area is briefly reviewed, and the potential applications of these complexes are highlighted. The primary aims of this course of work are outlined, namely, to develop a controlled synthetic approach to the synthesis of oligonuclear ruthenium acetylide complexes. The synthetic strategies for this aim are introduced in Chapter 2, and the synthetic routes to cis and trans-Ru(CH3)2(dmpe)2 (25/23) and cis and trans-Ru(CH3)2(depe)2 (26/24) are described. Characterisation of the novel, synthetically important trans-Ru(CH3)2(dmpe)2 (23) is completed by an examination of its X-Ray crystallographic structure. Chapter 3 describes the thermal and photochemical metathesis reactions of trans-Ru(CH3)2(dmpe)2 (23) with terminal acetylenes, and the preparation of a variety of acetylidomethylruthenium(II) complexes, trans-Ru(CH3)(C≡CR)(dmpe)2 (R = Ph (30), tBu (31), SiMe3 (32), C6H4-4-tBu (33), C6H3-3,5-tBu2 (34), C6H4-4-C≡CH (35), C6H4-4-OCH3 (36), C6H4-4-CH3 (37), C6H3-3,5-(CF3)2 (38)). The characterisation of these complexes by NMR spectroscopy, IR spectroscopy and X-Ray crystallography is presented. A clean and high yielding synthesis of the synthetically significant unsymmetrical bis(acetylido)ruthenium(II) complexes was developed via the reaction of an acetylidomethylruthenium(II) complex with an excess of a second terminal alkyne in a mixture of methanol and benzene. The characterisation of the novel complexes trans-Ru(C≡CR)(C≡CR′)(dmpe)2 (R = Ph, R′ = tBu (40), SiMe3 (41), C6H4-4-C≡CH (44); R = tBu, R′ = SiMe3 (42), C6H4-4-C≡CH (43), C6H4-4-tBu (45), C6H3-3,5-tBu2 (46)) by NMR and IR spectroscopy, mass spectrometry and X-Ray crystallography is described in Chapter 4. Additionally, Chapter 4 describes the synthesis and characterisation of symmetrical bis(acetylido)ruthenium(II) complexes, and a number of organic butenyne compounds, which were observed as by-products from the attempted synthesis of several of the bis(acetylido)ruthenium(II) complexes. Dinuclear ruthenium(II) complexes were prepared by the reaction of trans-Ru(C≡CR)(C≡CC6H4-4-C≡CH)(dmpe)2 (R = tBu (43) or Ph (44)) with an acetylidomethylruthenium(II) complex in toluene and methanol. Both symmetrical and unsymmetical dinuclear complexes could be prepared in this way, and were characterised by a range of techniques including NMR spectroscopy, IR spectroscopy, mass spectrometry and X-Ray crystallography, and are described in Chapter 5. In addition, an electrochemical study of one of the dinuclear complexes was undertaken using cyclic voltammetry. The symmetrical trinuclear ruthenium(II) complexes, trans,trans,trans- (RC≡C)Ru(dmpe)2(μ-C≡CC6H4C≡C)Ru(depe)2(μ-C≡CC6H4C≡C)Ru(dmpe)2(C≡CR) (R = Ph (80), tBu (81), SiMe3 (82)) was prepared by the reaction of two equivalents of an acetylidomethylruthenium(II) complex with the symmetrical bis(acetylido)ruthenium(II) complex, trans-Ru(C≡CC6H4-4-C≡CH)2(depe)2 (54), in toluene and methanol. These syntheses, and the subsequent characterisation of the products are also reported in Chapter 5. The primary aim of this thesis, viz. the synthesis and characterisation of acetylide bridged di- and trinuclear ruthenium acetylide complexes in a controlled fashion, was successfully achieved. Suggestions for future work are described in Chapter 6.

This thesis describes the synthesis and characterisation of a variety of acetylide-bridged di- and trinuclear ruthenium acetylide complexes that were prepared in a controlled fashion, and the preparation and characterisation of the ruthenium(II) complexes required for these stepwise reactions. These precursor complexes, or building blocks, include dimethyl-, acetylidomethyl-, and bis(acetylido)ruthenium(II) complexes. An introduction to metal acetylide chemistry is presented in Chapter 1. The previous research in this area is briefly reviewed, and the potential applications of these complexes are highlighted. The primary aims of this course of work are outlined, namely, to develop a controlled synthetic approach to the synthesis of oligonuclear ruthenium acetylide complexes. The synthetic strategies for this aim are introduced in Chapter 2, and the synthetic routes to cis and trans-Ru(CH3)2(dmpe)2 (25/23) and cis and trans-Ru(CH3)2(depe)2 (26/24) are described. Characterisation of the novel, synthetically important trans-Ru(CH3)2(dmpe)2 (23) is completed by an examination of its X-Ray crystallographic structure. Chapter 3 describes the thermal and photochemical metathesis reactions of trans-Ru(CH3)2(dmpe)2 (23) with terminal acetylenes, and the preparation of a variety of acetylidomethylruthenium(II) complexes, trans-Ru(CH3)(C≡CR)(dmpe)2 (R = Ph (30), tBu (31), SiMe3 (32), C6H4-4-tBu (33), C6H3-3,5-tBu2 (34), C6H4-4-C≡CH (35), C6H4-4-OCH3 (36), C6H4-4-CH3 (37), C6H3-3,5-(CF3)2 (38)). The characterisation of these complexes by NMR spectroscopy, IR spectroscopy and X-Ray crystallography is presented. A clean and high yielding synthesis of the synthetically significant unsymmetrical bis(acetylido)ruthenium(II) complexes was developed via the reaction of an acetylidomethylruthenium(II) complex with an excess of a second terminal alkyne in a mixture of methanol and benzene. The characterisation of the novel complexes trans-Ru(C≡CR)(C≡CR′)(dmpe)2 (R = Ph, R′ = tBu (40), SiMe3 (41), C6H4-4-C≡CH (44); R = tBu, R′ = SiMe3 (42), C6H4-4-C≡CH (43), C6H4-4-tBu (45), C6H3-3,5-tBu2 (46)) by NMR and IR spectroscopy, mass spectrometry and X-Ray crystallography is described in Chapter 4. Additionally, Chapter 4 describes the synthesis and characterisation of symmetrical bis(acetylido)ruthenium(II) complexes, and a number of organic butenyne compounds, which were observed as by-products from the attempted synthesis of several of the bis(acetylido)ruthenium(II) complexes. Dinuclear ruthenium(II) complexes were prepared by the reaction of trans-Ru(C≡CR)(C≡CC6H4-4-C≡CH)(dmpe)2 (R = tBu (43) or Ph (44)) with an acetylidomethylruthenium(II) complex in toluene and methanol. Both symmetrical and unsymmetical dinuclear complexes could be prepared in this way, and were characterised by a range of techniques including NMR spectroscopy, IR spectroscopy, mass spectrometry and X-Ray crystallography, and are described in Chapter 5. In addition, an electrochemical study of one of the dinuclear complexes was undertaken using cyclic voltammetry. The symmetrical trinuclear ruthenium(II) complexes, trans,trans,trans- (RC≡C)Ru(dmpe)2(μ-C≡CC6H4C≡C)Ru(depe)2(μ-C≡CC6H4C≡C)Ru(dmpe)2(C≡CR) (R = Ph (80), tBu (81), SiMe3 (82)) was prepared by the reaction of two equivalents of an acetylidomethylruthenium(II) complex with the symmetrical bis(acetylido)ruthenium(II) complex, trans-Ru(C≡CC6H4-4-C≡CH)2(depe)2 (54), in toluene and methanol. These syntheses, and the subsequent characterisation of the products are also reported in Chapter 5. The primary aim of this thesis, viz. the synthesis and characterisation of acetylide bridged di- and trinuclear ruthenium acetylide complexes in a controlled fashion, was successfully achieved. Suggestions for future work are described in Chapter 6.

Important reactions are catalyzed by enzymes employing polynuclear cofactors, often characterized by weak-field ligands and transition metal ions within the sum of the van der Waals radii. While the overall stoichiometries and, in many cases, the structures, of the cofactors are known, the roles of the individual metal ions remain uncertain. Our approach is to investigate model clusters stabilized by a hexadentate, trinucleating ligand. The hexaamine ligand \((MeC (CH_2NHC_6H_4-o-NHPh)_3) (^{Ph}LH_6)\) allows facile synthesis of the clusters \((^{Ph}L)Fe_3(thf)_3\), \((^{Ph}L)Fe_3 (py)_3\), and \((^{Ph}L)Fe_3(PMe_2Ph)_3\) (thf = tetrahydrofuran, py = pyridine). The phenyl substituents on the ligand sterically prevent strong M–M bonding, but permit weaker M–M orbital interactions, with Fe–Fe distances near those found in Fe metal. The complex \((^{Ph}L)Fe_3(thf)_3\) exhibits a well-isolated S = 5 or S = 6 ground state over 5 - 300 K, as evidenced by magnetic susceptibility and reduced magnetization data. However, in the stronger-field pyridine and phosphine complexes, temperature dependent susceptibility is observed which is best modeled as a spin state transition from S = 2 to S = 4. Variable-temperature crystallography and Mössbauer spectroscopy reveal a whole-molecule, rather than site-isolated, spin transition. The all-ferrous cluster \((^{Ph}L)Fe_3(thf)_3\) can be oxidized with triphenylmethyl halides or iodine to give singly-oxidized clusters of the form \((^{Ph}L)Fe_3X(L)\) and \([(^{Ph}L)Fe_3(\mu-X)]_2 (X = Cl, Br, I; L = thf, py)\), in which one Fe–Fe distance contracts to 2.30 Å and the others lengthen to 2.6-2.7 Å. The halide and solvent ligands coordinate a unique Fe, but Mössbauer spectroscopy shows that the diiron pair bears the oxidation. Magnetic data can be modeled by considering a high-spin ferrous ion ferromagnetically coupled to an \(S = 3/2 [Fe_2]^{5+}\) unit. When \([(^{Ph}L)Fe_3(\mu-Cl)]_2\) is reacted with two or five equivalents of \(CoCl_2\) in tetrahydrofuran, the fully-substituted complexes \((^{Ph}L)Fe_2CoCl(acn)\) and \((^{Ph}L)FeCo_2Cl(acn)\) (acn = acetonitrile) can be isolated. \(^1H\) nuclear magnetic resonance shows that they are distinct species, not a mixture, and the elemental ratios are confirmed by X-ray fluorescence spectroscopy. Mössbauer spectroscopy shows that the Co preferentially substitutes into the \([M_2]^{5+}\) unit, as the ferrous site doublet is completely absent in \((^{Ph}L)FeCo_2Cl(acn)\). / Chemistry and Chemical Biology

Resumo O presente trabalho teve como objetivo sintetizar e caracterizar um novo complexo trinuclear de rutênio, [Ru3O(CH3OO)6(3-pic)2(NO)]+, através de rotas sintéticas previamente descritas na literatura para complexos análogos. Para a obtenção deste complexo, foram necessárias cinco etapas de síntese, cada qual gerando o precursor da etapa seguinte. Os complexos precursores [Ru3O(CH3OO)6(3-pic)3]+, [Ru3O(CH3OO)6(3-pic)2(CO)] e [Ru3O(CH3OO)6(3-pic)2(H2O)]+, foram caracterizados por técnicas espectroscópicas e voltamétricas. Para o complexo de interesse, [Ru3O(CH3OO)6(3-pic)2(NO)]+, além da caracterização por técnicas espectroscópicas e voltamétricas, foram realizados estudos de fotólise e de interação com albumina de soro humano (HSA). Pelas técnicas espectroscópicas, pudemos ratificar as estruturas propostas tanto para o nitrosilo quanto para os precursores estudados. Para a caracterização do complexo [Ru3O(CH3OO)6(3-pic)2(NO)]+, utilizando a técnica de espectroscopia de infravermelho verificamos a coordenação do ligante NO ao centro metálico [Ru3O], devido ao estiramento característico deste ligante. Os espectros de absorção UV-vis e RMN mostraram que existe uma forte interação entre o elétron desemparelhado do centro metálico e o elétron do ligante NO. Pelos estudos de voltametria cíclica, observamos que os processos redox envolvendo o ligante NO, são compartilhados com o centro metálico. A fotólise do complexo [Ru3O(CH3OO)6(3-pic)2(NO)]+, mostrou-se eficiente, uma vez que a liberação fotoinduzida do NO ocorreu na região do visível e em pH fisiológico. Pelos estudos de supressão de fluorescência, observamos que o complexo realmente interage com a HSA na proporção de 1:1, na região em que se encontra o resíduo de triptofano. / The aim of the present study was synthesize and characterize a new trinuclear ruthenium complex, [Ru3O(CH3OO)6(3-pic)2(NO)]+, via synthetic routes previously described in the literature for analogous complexes. To obtain this complex, it took five synthetic steps, each one yielding a precursor for the next step. The precursor complexes [Ru3O(CH3OO)6(3-pic)3]+, [Ru3O(CH3OO)6(3-pic)2(CO)] and [Ru3O(CH3OO)6(3-pic)2(H2O)]+, were characterized by spectroscopic and voltammetric techniques. For the complex of interest, [Ru3O(CH3OO)6(3-pic)2(NO)]+, in addition to characterization by spectroscopic and voltammetric studies, it was carried out photolysis and interaction with human serum albumin. By spectroscopic techniques, we could confirm the proposed structures for both the nitrosyl and precursors. For characterization of the complex [Ru3O(CH3OO)6(3-pic)2(NO)]+, infrared spectroscopy allowed us to verify that the ligand coordination to the metal center [Ru3O], due to the characteristic stretching band of that ligand. The absorption spectra of UV-vis and NMR showed that there is a strong interaction between the unpaired electron of the metal center and the NO ligand. By cyclic voltammetry studies, we observed that the redox processes involving the NO ligand are shared with the metal center processes. The photolysis of the complex [Ru3O (CH3OO) 6 (3-pic) 2 (NO)] +, was efficient, since the photoinduced release of NO occurred in the visible region and at physiological pH. By fluorescence quenching studies, we observed that the complex actually interacts with the HSA in a 1:1 ratio, in the region which is the residue of tryptophan.

Resumo O presente trabalho teve como objetivo sintetizar e caracterizar um novo complexo trinuclear de rutênio, [Ru3O(CH3OO)6(3-pic)2(NO)]+, através de rotas sintéticas previamente descritas na literatura para complexos análogos. Para a obtenção deste complexo, foram necessárias cinco etapas de síntese, cada qual gerando o precursor da etapa seguinte. Os complexos precursores [Ru3O(CH3OO)6(3-pic)3]+, [Ru3O(CH3OO)6(3-pic)2(CO)] e [Ru3O(CH3OO)6(3-pic)2(H2O)]+, foram caracterizados por técnicas espectroscópicas e voltamétricas. Para o complexo de interesse, [Ru3O(CH3OO)6(3-pic)2(NO)]+, além da caracterização por técnicas espectroscópicas e voltamétricas, foram realizados estudos de fotólise e de interação com albumina de soro humano (HSA). Pelas técnicas espectroscópicas, pudemos ratificar as estruturas propostas tanto para o nitrosilo quanto para os precursores estudados. Para a caracterização do complexo [Ru3O(CH3OO)6(3-pic)2(NO)]+, utilizando a técnica de espectroscopia de infravermelho verificamos a coordenação do ligante NO ao centro metálico [Ru3O], devido ao estiramento característico deste ligante. Os espectros de absorção UV-vis e RMN mostraram que existe uma forte interação entre o elétron desemparelhado do centro metálico e o elétron do ligante NO. Pelos estudos de voltametria cíclica, observamos que os processos redox envolvendo o ligante NO, são compartilhados com o centro metálico. A fotólise do complexo [Ru3O(CH3OO)6(3-pic)2(NO)]+, mostrou-se eficiente, uma vez que a liberação fotoinduzida do NO ocorreu na região do visível e em pH fisiológico. Pelos estudos de supressão de fluorescência, observamos que o complexo realmente interage com a HSA na proporção de 1:1, na região em que se encontra o resíduo de triptofano. / The aim of the present study was synthesize and characterize a new trinuclear ruthenium complex, [Ru3O(CH3OO)6(3-pic)2(NO)]+, via synthetic routes previously described in the literature for analogous complexes. To obtain this complex, it took five synthetic steps, each one yielding a precursor for the next step. The precursor complexes [Ru3O(CH3OO)6(3-pic)3]+, [Ru3O(CH3OO)6(3-pic)2(CO)] and [Ru3O(CH3OO)6(3-pic)2(H2O)]+, were characterized by spectroscopic and voltammetric techniques. For the complex of interest, [Ru3O(CH3OO)6(3-pic)2(NO)]+, in addition to characterization by spectroscopic and voltammetric studies, it was carried out photolysis and interaction with human serum albumin. By spectroscopic techniques, we could confirm the proposed structures for both the nitrosyl and precursors. For characterization of the complex [Ru3O(CH3OO)6(3-pic)2(NO)]+, infrared spectroscopy allowed us to verify that the ligand coordination to the metal center [Ru3O], due to the characteristic stretching band of that ligand. The absorption spectra of UV-vis and NMR showed that there is a strong interaction between the unpaired electron of the metal center and the NO ligand. By cyclic voltammetry studies, we observed that the redox processes involving the NO ligand are shared with the metal center processes. The photolysis of the complex [Ru3O (CH3OO) 6 (3-pic) 2 (NO)] +, was efficient, since the photoinduced release of NO occurred in the visible region and at physiological pH. By fluorescence quenching studies, we observed that the complex actually interacts with the HSA in a 1:1 ratio, in the region which is the residue of tryptophan.

Três novas supermoléculas, aqui designadas por ZnTCP4+, MnTCP5+ e CoTCP5+, foram obtidas pela coordenação de quatro acetatos trinucleares assimétricos de rutênio, [Ru3O(CH3CO2)6(py)2(CH3OH)]+, aos resíduos piridínicos de meso-tetra(4-piridil)porfirinato de ZnII, MnIII e CoIII, respectivamente (ZnTPyP, MnTPyP e CoTPyP). A caracterização destas supermoléculas foi efetuada por espectroscopia de ressonância magnética nuclear e espectroscopia eletrônica. O comportamento eletroquímico foi investigado por voltametria cíclica e espectroeletroquímica. Os efeitos dos acetatos trinucleares periféricos sobre a reatividade do núcleo porfirínico foram analisados: (i) para ZnTCP4+, além da supressão da luminescência, verificou-se que as constantes de coordenação axial determinadas em diclorometano para piridina e imidazol, quando comparadas às respectivas constantes de ZnTPyP e de meso-tetra(fenil)porfirinato de zinco, indicaram um aumento significativo da acidez de Lewis do íon Zn2+; (ii) MnTCP5+ revelou-se um catalisador mais seletivo que MnTPyP na oxidação de ciclohexano em fase homogênea, utilizando-se iodosilbenzeno como doador de oxigênio; (iii) os eletrodos modificados por filmes de CoTCP5+ apresentaram uma eficiente atividade catalítica na redução tetra-eletrônica de dioxigênio a água, comportamento que contrasta com o descrito na literatura para filmes de CoTPyP. A redução tetra-eletrônica de dioxigênio catalisada pelos filmes de CoTCP5+ foi confirmada por voltametria cíclica, voltametria de eletrodo disco rotatório e voltametria de eletrodo de anel e disco rotatórios. / Three novel supermolecules designated as ZnTCP4+, MnTCP5+, and CoTCP5+ were obtained by coordination of four assymetric trinuclear ruthenium acetate species, [Ru3O(CH3CO2)6(py)2(CH3OH)]+ to pyridine residues of ZnII -, MnIII -, and CoIIITPyP, respectively (TPyP = meso-tetra(4-pyridil)porphyrinate). These new compounds were characterized by nuclear magnetic resonance spectroscopy and electronic spectroscopy. The electrochemical behavior was investigated by cyclic voltammetry, and spectroelectrochemistry. The influence of the peripheral trinuclear acetate on the porphyrin core reactivity was assayed: (i) for ZnTCP4+, besides the luminescence quenching, the calculated equilibrium constants for axial coordination of pyridine and imidazole in dichloromethane demonstrated a significant increase in the Zn2+ Lewis acidity in comparison with the respective constants from ZnTPyP and zinc meso-tetra(phenyl)porphyrinate; (ii) MnTCP5+ exhibited improved selectivity as catalyst for ciclohexane oxidation (homogeneous phase) in comparison with MnTPyP using iodosylbenzene as oxygen donor; (iii) modified electrodes by CoTCP5+ films showed an outstanding catalytic activity in the tetraelectronic reduction of dioxygen to water, in contrast with CoTPyP films described in the literature; the dioxygen tetraelectronic reduction was confirmed by cyclic voltammetry, rotating disk electrode voltammetry, and rotating ring and disk electrode voltammetry.

Três novas supermoléculas, aqui designadas por ZnTCP4+, MnTCP5+ e CoTCP5+, foram obtidas pela coordenação de quatro acetatos trinucleares assimétricos de rutênio, [Ru3O(CH3CO2)6(py)2(CH3OH)]+, aos resíduos piridínicos de meso-tetra(4-piridil)porfirinato de ZnII, MnIII e CoIII, respectivamente (ZnTPyP, MnTPyP e CoTPyP). A caracterização destas supermoléculas foi efetuada por espectroscopia de ressonância magnética nuclear e espectroscopia eletrônica. O comportamento eletroquímico foi investigado por voltametria cíclica e espectroeletroquímica. Os efeitos dos acetatos trinucleares periféricos sobre a reatividade do núcleo porfirínico foram analisados: (i) para ZnTCP4+, além da supressão da luminescência, verificou-se que as constantes de coordenação axial determinadas em diclorometano para piridina e imidazol, quando comparadas às respectivas constantes de ZnTPyP e de meso-tetra(fenil)porfirinato de zinco, indicaram um aumento significativo da acidez de Lewis do íon Zn2+; (ii) MnTCP5+ revelou-se um catalisador mais seletivo que MnTPyP na oxidação de ciclohexano em fase homogênea, utilizando-se iodosilbenzeno como doador de oxigênio; (iii) os eletrodos modificados por filmes de CoTCP5+ apresentaram uma eficiente atividade catalítica na redução tetra-eletrônica de dioxigênio a água, comportamento que contrasta com o descrito na literatura para filmes de CoTPyP. A redução tetra-eletrônica de dioxigênio catalisada pelos filmes de CoTCP5+ foi confirmada por voltametria cíclica, voltametria de eletrodo disco rotatório e voltametria de eletrodo de anel e disco rotatórios. / Three novel supermolecules designated as ZnTCP4+, MnTCP5+, and CoTCP5+ were obtained by coordination of four assymetric trinuclear ruthenium acetate species, [Ru3O(CH3CO2)6(py)2(CH3OH)]+ to pyridine residues of ZnII -, MnIII -, and CoIIITPyP, respectively (TPyP = meso-tetra(4-pyridil)porphyrinate). These new compounds were characterized by nuclear magnetic resonance spectroscopy and electronic spectroscopy. The electrochemical behavior was investigated by cyclic voltammetry, and spectroelectrochemistry. The influence of the peripheral trinuclear acetate on the porphyrin core reactivity was assayed: (i) for ZnTCP4+, besides the luminescence quenching, the calculated equilibrium constants for axial coordination of pyridine and imidazole in dichloromethane demonstrated a significant increase in the Zn2+ Lewis acidity in comparison with the respective constants from ZnTPyP and zinc meso-tetra(phenyl)porphyrinate; (ii) MnTCP5+ exhibited improved selectivity as catalyst for ciclohexane oxidation (homogeneous phase) in comparison with MnTPyP using iodosylbenzene as oxygen donor; (iii) modified electrodes by CoTCP5+ films showed an outstanding catalytic activity in the tetraelectronic reduction of dioxygen to water, in contrast with CoTPyP films described in the literature; the dioxygen tetraelectronic reduction was confirmed by cyclic voltammetry, rotating disk electrode voltammetry, and rotating ring and disk electrode voltammetry.

Este trabalho apresenta a síntese e a caracterização de quatro complexos trinucleares de acetato de rutênio, de fórmula geral [Ru3O(CH3COO)6(L)2(CO)] nos quais L são ligantes N-heterocíclicos 4-aminopiridina, isonicotinamida, 4-(dimetil)aminopiridina e 2,6-dimetilpirazina com características -aceptoras ou -doadoras. Os derivados de rutênio foram sintetizados de acordo com adaptações de rotas sintéticas já reportadas na literatura, e caracterizados por meio de técnicas de cunho espectroscópico, eletroquímico e outras, a saber: análise elementar, 1H RMN, absorção UV-vis, infra-vermelho, voltametria cíclica e difração de raios-X. Foi investigada a liberação fotoinduzida de monóxido de carbono proveniente dos complexos trinucleares em acetonitrila, por meio de acompanhamento espectrofotométrico. O rendimento quântico envolvido na liberação do CO foi calculado por meio de actinometria química. Foi estudada a interação entre os complexos com as biomoléculas HSA e o DNA de timo de bezerro por meio das técnicas espectroscópicas de fluorescência, UV-vis e dicroísmo circular. Além disso, foram realizados ensaios preliminares in vitro para avaliar a citotoxicidade dos complexos frente a uma linhagem de células de melanoma murinho (B16F10) e foi avaliada a atividade tripanocida dos complexos sobre a forma amastigota do parasita Tripanossoma cruzi. / This work describes the synthesis and characterization of four ruthenium trinuclear complex of general formula [Ru3O(CH3COO)6(CO)(L)2] where L = 2,6-dimethylaminopyridine; isonicotinamide; 4-aminopyridine and 4-dimethylpyrazine (N-heterocyclic ligands with -acceptor or -donor characteristics). The ruthenium derivatives were synthesized according to adaptations of synthetic routes already reported in literature and characterized by spectroscopic and electrochemical techniques such as nuclear magnetic ressonance (NMR), UV-vis, infrared, cyclic voltammetry, X-ray diffraction and elemental analysis. The photoinduced release of carbon monoxide in acetonitrile was investigated by means of spectrophotometric monitoring. The quantum yield involved in the CO release was calculated by chemical actinometry. It was studied the interaction between the complexes with the biomolecules HSA and calf thymus DNA by spectroscopic techniques of fluorescence, UV-vis and circular dichroism. In addition, preliminary tests were performed in vitro in order to evaluate the cytotoxicity of the complexes against a murine melanoma cell line (B16F10) and trypanocidal activity of the complexes over the amastigote form of the parasite Trypanosoma cruzi.

Este trabalho apresenta a síntese e a caracterização de quatro complexos trinucleares de acetato de rutênio, de fórmula geral [Ru3O(CH3COO)6(L)2(CO)] nos quais L são ligantes N-heterocíclicos 4-aminopiridina, isonicotinamida, 4-(dimetil)aminopiridina e 2,6-dimetilpirazina com características -aceptoras ou -doadoras. Os derivados de rutênio foram sintetizados de acordo com adaptações de rotas sintéticas já reportadas na literatura, e caracterizados por meio de técnicas de cunho espectroscópico, eletroquímico e outras, a saber: análise elementar, 1H RMN, absorção UV-vis, infra-vermelho, voltametria cíclica e difração de raios-X. Foi investigada a liberação fotoinduzida de monóxido de carbono proveniente dos complexos trinucleares em acetonitrila, por meio de acompanhamento espectrofotométrico. O rendimento quântico envolvido na liberação do CO foi calculado por meio de actinometria química. Foi estudada a interação entre os complexos com as biomoléculas HSA e o DNA de timo de bezerro por meio das técnicas espectroscópicas de fluorescência, UV-vis e dicroísmo circular. Além disso, foram realizados ensaios preliminares in vitro para avaliar a citotoxicidade dos complexos frente a uma linhagem de células de melanoma murinho (B16F10) e foi avaliada a atividade tripanocida dos complexos sobre a forma amastigota do parasita Tripanossoma cruzi. / This work describes the synthesis and characterization of four ruthenium trinuclear complex of general formula [Ru3O(CH3COO)6(CO)(L)2] where L = 2,6-dimethylaminopyridine; isonicotinamide; 4-aminopyridine and 4-dimethylpyrazine (N-heterocyclic ligands with -acceptor or -donor characteristics). The ruthenium derivatives were synthesized according to adaptations of synthetic routes already reported in literature and characterized by spectroscopic and electrochemical techniques such as nuclear magnetic ressonance (NMR), UV-vis, infrared, cyclic voltammetry, X-ray diffraction and elemental analysis. The photoinduced release of carbon monoxide in acetonitrile was investigated by means of spectrophotometric monitoring. The quantum yield involved in the CO release was calculated by chemical actinometry. It was studied the interaction between the complexes with the biomolecules HSA and calf thymus DNA by spectroscopic techniques of fluorescence, UV-vis and circular dichroism. In addition, preliminary tests were performed in vitro in order to evaluate the cytotoxicity of the complexes against a murine melanoma cell line (B16F10) and trypanocidal activity of the complexes over the amastigote form of the parasite Trypanosoma cruzi.