文摘
The electrochemistry of elemental sulfur (S8) and the polysulfides Na2S4 and Na2S6 has been studied for the first time in nonchloroaluminate ionic liquids. The cyclic voltammetry of S8 in the ionic liquids is different to the behavior reported in some organic solvents, with two reductions and one oxidation peak observed. Supported by in situ UV鈥搗is spectro-electrochemical experiments, the main reduction products of S8 in [C4mim][DCA] ([C4mim] = 1-butyl-3-methylimidazolium; DCA = dicyanamide) have been identified as S62鈥?/sup> and S42鈥?/sup>, and plausible pathways for the formation of these species are proposed. Dissociation and/or disproportionation of the polyanions S62鈥?/sup> and S42鈥?/sup> appears to be slow in the ionic liquid, with only small amounts of the blue radical species S3鈥⑩€?/sup> formed in the solutions at r.t., in contrast with that observed in most molecular solvents.