Kinetics of oxidation of transition-metal ions by halogen radical anions. Part II. The oxidation of cobalt(II) by dichloride ions generated by flash photolysis

The radical anion Cl2–, generated by flash photolysis of solutions containing Cl3–, oxidizes cobalt(II) to cobalt(III). At 25 °C and I= 0·3M, the rate constant is (1·4 ± 0·2)× 106 l mol–1 s–1(ΔH‡= 29 ± 4 kJ mol–1 and ΔS‡=–31 ±10 J K–1 mol–1). The reaction is inner sphere–substitution controlled, the initial product being CoCl2+ which is not labile on the time scale of the oxidation reaction.