School of Chemistry and Chemical Engineering, The QUILL Centre, Queen's University, Belfast BT9 5AG, United Kingdom.
J Phys Chem B. 2011 Dec 1;115(47):13873-9. doi: 10.1021/jp208159v. Epub 2011 Nov 3.
The electrochemistry of elemental sulfur (S(8)) and the polysulfides Na(2)S(4) and Na(2)S(6) has been studied for the first time in nonchloroaluminate ionic liquids. The cyclic voltammetry of S(8) 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-vis spectro-electrochemical experiments, the main reduction products of S(8) in [C(4)mim][DCA] ([C(4)mim] = 1-butyl-3-methylimidazolium; DCA = dicyanamide) have been identified as S(6)(2-) and S(4)(2-), and plausible pathways for the formation of these species are proposed. Dissociation and/or disproportionation of the polyanions S(6)(2-) and S(4)(2-) appears to be slow in the ionic liquid, with only small amounts of the blue radical species S(3)(•-) formed in the solutions at r.t., in contrast with that observed in most molecular solvents.
首次在非氯铝酸盐离子液体中研究了元素硫 (S(8)) 和多硫化物 Na(2)S(4) 和 Na(2)S(6) 的电化学。S(8) 在离子液体中的循环伏安行为与在一些有机溶剂中报道的行为不同，观察到两个还原峰和一个氧化峰。通过原位紫外可见光谱电化学实验的支持，已确定 S(8) 在 [C(4)mim][DCA]（[C(4)mim] = 1-丁基-3-甲基咪唑鎓；DCA = 双氰胺）中的主要还原产物为 S(6)(2-) 和 S(4)(2-)，并提出了形成这些物质的可能途径。在离子液体中，多阴离子 S(6)(2-) 和 S(4)(2-) 的解离和/或歧化似乎很慢，只有少量蓝色自由基物种 S(3)(•-) 在室温下在溶液中形成，与在大多数分子溶剂中观察到的情况形成对比。
