KINETICS OF OXIDATION OF SCN- BY DIPERIODATO CUPRATE(III) (DPC) IN ALKALINE-MEDIUM

The kinetics of oxidation of SCN- by DPC has been investigated in alka line medium. The reaction shows first-order dependence in [SCN-]. The pseudo-first-order rate constant (k(obs)) changes differently under di fferent [OH-(]). At low [OH-], k(obs) decreases when [OH-] increases, but when [OH-] increases to enough extent, k(obs) increases with incre ase in [OH-]. Free radicals were observed in the process of reaction. A plausible mechanism involving Cu(HL)(2) and CuL as active substrates in the reaction has been proposed. The rate equations derived from th e mechanism explain ail the experimental phenomena satisfactorily. (C) 1996 John Wiley & Sons, Inc.