C_(60)系列螺亚甲基衍生物的电化学性质

Electrochemical Properties of Methanofullerenes

考虑到在生物、新型材料等方面的应用,采用循环伏安(CV)的方法,系统研究了11个C60螺亚甲基衍生物的电化学性质.分析比较了螺碳原子上所连不同基团的性质及链的长度等因素对C60得电子能力的影响.结果发现,引入推电子基团,如烷基,会使C60得电子能力降低,第一个还原电位有较大的负移;引入具有拉电子性质的基团,如羧酸酯基,则会部分抵消由于C60共轭结构被破坏而引起的电位负移,结果使得电位负移值减少.增加引入基团链的长度对C60的得电子的能力影响较小.同时,对于因电化学反应所引起的异构化而使还原峰发生分裂的现象作了解释.

11 methanofullerenes have been investigated using cyclic voltammetry(CV) systematically and comparatively. The influence of the nature of groups introduced and chain length of substituents on the electron-accepting ability of methanofullerenes was observed. It was found that introducing electron-donating groups, such as alkyls, weaken the electron-accepting ability of C-60 and make its first reduction wave shifted to more negative position. Introducing electron-withdrawing groups, such as carboxylic ester groups, compensate part of negative shift of the reduction wave due to the effect of the saturation of a fullerene double bond. It was also found that increasing the chain length of substituents would not obviously change the electron-accepting ability of C-60. Furthermore, the split of reduction peaks of some methanofullerenes induced by electrochemical isomerization was explained.