Experimental and quantum chemical modeling of the influence of the pH of the medium on the NO-donor activity of the mononuclear nitrosyl iron complex [Fe(SC(NH2)2)2(NO)2]Сl•H2O

Abstract

The electrochemical method and quantum chemical modeling were used to study the NO-donor activity of the mononuclear nitrosyl complex with the thiourea ligand and the influence of the pH of the medium on the reaction. It is shown experimentally that this complex evolves nitrogen monoxide and the character of this process depends on the pH of the medium. For a neutral medium, the curve of nitrogen monoxide evolution reaches a plateau, whereas the curve increases linearly with time for an alkaline medium. The quantum chemical modeling (using DFT methods with the B3LYP and BP86 functionals) of possible processes in an aqueous solution of the complex in neutral and alkaline media allowed us to propose the schemes of the NO-donation reaction, which explain the experimental data on the pH effect.