Reactivity of sulphuryl chloride in acetonitrile with the elements

Abstract

Sulphuryl chloride in MeCN reacts with all but the most refractory elements to give mainly solvated chlorides at or below 300 K in contrast with SO₂Cl₂ alone which requires at least twice this temperature. There is evidence for an ionic mechanism based on analogy, thermochemistry, transport measurements and additive effects. The instability of these solutions leading to polymerization, together with its inhibition, is described. Sulphur dioxide formed in reactions seldom plays a reductive role apart from influencing formation of the mixed-valence Tl₄Cl₆. Semiquantitative kinetic measurements in different solvents emphasize the uniqueness of MeCN. For most elements attack is diffusion controlled across surface films giving a parabolic dependence on time which can be linearized if film growth is prevented by changing the solvent mix. The varied nature of these surface films vitiates any simple relation between rate and periodicity. Some applications are indicated.