Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

The kinetics of oxidation of [Co(en)₂SCH₂COO]⁺ with S₂O₈^2- was studied in water-methanol and water-tert-butyl alcohol mixtures. Changes in the reaction activation parameters ∆H^≠ and ∆S^≠ with varying concentration of the co-solvent depend on the kind of the latter, which points to a significant role of salvation effects. The solvation effect on the reaction is discussed based on a comparison of the transfer functions ∆H_t⁰, ∆S_t⁰ and ∆G_t⁰ for the initial and transition states with the changes in the activation parameters accompanying changes in the CO-solvent concentration. The transfer enthalpies of the reactant were obtained from calorimetric measurements.