Oxidation of thiourea and thioacetamide by octacyanomolybdate(v) anion in perchloric acid

Summary The kinetics of the reduction of octacyanomolybdate(V) anion by thiourea and thioacetamide have been studied in aqueous HClO₄ at constant ionic strengthI=0.10 mol dm^–3 (NaClO₄). The rate of oxidation of these substrates by the oxidant shows a first order dependence in both the oxidant and the substrates and while the thiourea system exhibits an inverse first-order dependence on H⁺] that of thioacetamide is found to be first-order in H⁺]. The variation observed in H⁺] dependences in these reactions is attributed to the nature of the thiourea in the pH range used in this study and the inductive effect of the methyl group in thioacetamide. A mechanistic interpretation of these observations is advanced.