Kinetic and thermodynamic study of thiolato and sulfenato Co(III) complexes in water–acetonitrile mixtures

Rate constants are reported for peroxodisulfate as well as periodate oxidation ofCo(en)₂{SCH₂CH(COO)NH₂}]⁺, Co(en)₂(SCH₂CH₂NH₂)]²⁺, and Co(en)₂(SOCH₂CH₂NH₂)]²⁺ in water–acetonitrile mixtures. The dependence of rate constants on the acetonitrile concentration is established and discussed. Ancillary information relevant to solvation of reactants has been obtained from solvatochromism and from Gibbs transfer functions. The solvent effect is discussed from the viewpoint of change in solvation of initial and transition state on going from water to water–acetonitrile mixtures. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 36: 34–40, 2004