Platinum(II)-mediated disulfide/thiolate interconversion in organic disulfides: Density functional theory thermodynamic study

The thermodynamically density functional theory (DFT) calculations of reactions of the disulfides (l-cystine, cystamine, dl-homocystine, and 3,3 '-dithiodipropionic acid) with Pt(II) ions in aqueous media have been performed. SMD solvation model was fitted to take into account the solvation effects of the medium. DFT calculations predict the oxidative addition reaction with the formation of thiolate complexes of Pt(IV)-[PtCl4(S-R)(2)] which is consistent with experimental data. We propose a theoretical model that rationalizes the experimental data on Pt(II) interactions with homological disulfides. The role of explicit solvation in reactions is also investigated. We propose that the stability of S,S '-binuclear disulfide complexes correlates with the redistribution of charges on sulfur atoms. We compared MN15 and PBE0 functionals for the calculation of equilibrium constants.

Automated summary

The study conducted DFT calculations on the reactions of disulfides with Pt(II) ions in aqueous media, predicting oxidative addition reactions to form thiolate complexes of Pt(IV)- [PtCl4(S-R)(2)]. A theoretical model was proposed to rationalize experimental data on Pt(II) interactions with homological disulfides, and the role of explicit solvation in reactions was investigated. The stability of S,S'-binuclear disulfide complexes was found to correlate with the redistribution of charges on sulfur atoms, with MN15 and PBE0 functionals compared for equilibrium constants calculation.