Study of the mechanism of the manganese-catalysed oxidation of a thiol-containing organic compound

Abstract

The catalytic effect of manganese(II) on the oxidation of 2-hydroxynaphthaldehyde thiosemicarbazone is reported. The reagent is oxidised yielding a deep blue fluorescence. The oxidation is almost specific for manganese owing to its availability to form a complex with the reagent in a neutral or alkaline medium. The active species of the metal is manganese(III). The superoxide anion is generated, subsequently producing hydrogen peroxide. Evidence for this is that catalase inhibits the oxidation process and superoxide dismutase enhances it. The role played by manganese and a possible mechanism of reagent oxidation are proposed.