Reactions in mixed non-aqueous solution containing sulphur dioxide. Part 9. Mechanisms of dissolution of metals, oxides, and sulphites

Abstract

A new mechanistic pathway which explains the dissolution of metals into binary mixtures of SO₂ and dimethyl sulphoxide (dmso) is presented. The adduct, dmso·2SO₂, which is a component of these mixtures contains the S–O–S linkage necessary to the formation of [S₂O₇]^2–. The process must proceed through free-radical electron transfer and a series of O-atom transfer steps. The reactions of metal oxides and sulphites with dmso–SO₂ also conform to the mechanistic scheme proposed.