Desenvolvimento e aplicação de metodologias teóricas para o estudo de processos de interesse biológico envolvendo complexos de rutênio em solução

Abstract

In this thesis, we studied the ligand exchange reactions in aqueous chloride complexes that have some biological importance. The were chosen [Ru(NH3)5(Cl)]2+ e trans-[Ru(NH3)4(Py)(Cl)]2+ complexes. Calculations using the Density Functional Theory, by approximating hybrid QM / EFP, were performed to estimate the structural, electronic and energy properties of the reacting species, product and transition state along the potential energy curve. Studies of the coordination of Ru(NH3)5(H2O)]2+ and trans-[Ru(NH3)4(Py)(H2O)]2+ to DNA were performed to obtain the preferred coordination site, N3 or N7, to the adenine or guanine nucleobases. Using level of theory DFT and MP2 estimated the formation of adducts of Ru(II)-DNA, [Ru(NH3)4(Nucleobase)(L)]2+ for L= NH3 and L=Py. We also used the DFT for investigating the structure, the nature of the binding M(II)-NO and electronic spectra of the complexes M(imidazol)(PPIX)(L)]q, with M=Fe2+ and Ru2+ and L=NO+, NO e NO-, where all the possibilities for coordination (1-N, 1-O and 2-ON) were used. To study the nature of the binding we use the Charge Decomposition Analysis (CDA) and the Energy Decomposition Analysis (EDA). We use TD-DFT with the functional TPSSh to perform spectroscopic studies of complexes [Ru(imidazole)(PPIX)(NO)] and [Ru(imidazole)(PPIX)(NO+)].