Oxidation of Iodide and Other Inorganic Ions Employing Nonamolybdomanganate Ion ([MnMo9O32]6-) as Oxidant

Abstract

The nonamolybdomanganate ion (as (NH4)6[MnMo9O32].6H2O) is a water-soluble manganese(IV) oxidant which is stable in the pH range 3.0 – 5.0, and oxidises iodide, sulfite and oxalate anions in solution. The kinetics of the iodide oxidation display autocatalytic behaviour, associated with catalysis by low-valent manganese ion formed in the reaction. A pH dependence is associated with protonation equilibria of the cluster and or pH-dependent dissociation reactions of the cluster. Sulfite and oxalate oxidation proceeds via more complex multi-step pathways, but do not require inclusion of autocatalysis in the kinetic analysis.