Synthesis, characterization and reactivity studies of a ruthenium complex with sulfite ligands

Ruthenium complexes containing the sulfite ligand might release sulfur species in a physiological environment, including sulfite itself. his ion can react with nitrogenous bases such as cytosine, causing structural changes in DNA. Thus, such coordination compounds show potential applicability as antimicrobial agents. In this work, the coordination complex cis-Na₂[Ru(bpy)₂(SO₃)₂] was synthetized from the precursor cis-[Ru(bpy)₂Cl₂], which was obtained through the method proposed by Meyer and collaborators. The complex cis-Na₂[Ru(bpy)₂(SO₃)₂] was characterized by the following techniques: FTIR, NMR, UV-Vis spectroscopy, HPLC and cyclic voltammetry. Reactivity assays were performed in aqueous solutions, in which reactions were monitored by UV-Vis spectroscopy. The results of the reactivity assays provided information about a pH-dependent equilibrium previously reported in the literature and indicated the occurrence of a photolysis reaction, which might involve 2 steps.