Thermodynamic study of an effective catalytic system, hydrogen peroxide and methyltrioxorhenium

The thermodynamic of the known and very effective catalytic system, hydrogen peroxide (H2O2) and methyltrioxorhenium (MTO) is studied in different solvents using UV-Visible spectroscopic method. The thermodynamic parameters (?G, ?H and ?S) for two equilibrium reactions, MTO + H2O2 ? A + H2O and A + H2O2 ? B.H2O (A, [MeRe(O)2(O2)]; B.H2O, [MeRe(OH2)(O)(O2)2]), are determined. The obtained free energies of the reactions depend on dielectric constants of solvent, which are explained by Onsager’s reaction field theory.