CoTPP电化学催化还原溴代环己烷的机理  

Mechanism Study on Electrochemical Reduction of Co(Ⅱ)TPP/Cyclohexyl Bromide system

作　　者：严川伟[1] 刘雅言[1] 李洁[1] 林祥钦[1] 

机构地区：[1]中国科学院长春应用化学研究所电分析化学开放研究实验室国家电化学和光谱研究分析中心

出　　处：《应用化学》1995年第6期33-37,共5页Chinese Journal of Applied Chemistry

基　　金：国家自然科学基金资助课题

摘　　要：以电化学循环伏安、现场ＥＳＲ电化学以及现场薄层电化学方法研究了电生Ｃｏ（Ⅰ）ＴＰＰ与溴代环己烷的反应机制。在ＤＭＦ中，Ｃｏ（Ⅱ）／Ｃｏ（Ⅰ）的氧化还原有明显的催化溴代环己烷还原的特征，反应现场有自由基生成。反应产物之一是Ｃｏ—Ｃ键化合物，可以在－１．３０Ｖ（ＳＣＥ）一电子还原。当存在ＣＨ＿２＝ＣＨＣＮ时，生成另一种Ｃｏ—Ｃ键化合物，该化合物在—１．１０Ｖ（ＳＣＥ）处一电子还原。证明溴代环己烷与Ｃｏ（Ⅰ）ＴＰＰ反应主要是经过形成烷基自由基的机制进行的。The mechanism of electrochemical reactions of electrogenerated Co(Ⅰ)TPP andcyclohexyl bromide was investigated with cyclic voltammetry,in-situ ESR-spectroelec-trpchemistry and in-situ micro-electrode-CV thin-layer electrochemistry in DMF solution.The redox reaction of Co(Ⅱ)/Co(Ⅰ) parallelly catalyzed the reduction of cyclohexylbromide,and generated both the cyclohexyl radicals and Co-C bond compoundC6H11 Co(Ⅲ)TPP. Further reduction of the Co-C bond compound at-1.30V (SCE ) im-plied an EC mechanism,namely electrochemical reduction followed by Co-C bond splittingreaction which regenerated the cyclohexyl radicals with rate constant of 0. 73s￣(-1). The pres-ence of additional CH_2=CHCN led to the generation of a new Co-C bond compound whichgave rise to a reduction peak at-1. 10V (SCE).A mechanism for the Co(Ⅱ)TPP/cyclo-hexyl bromide system, suggesting that the cyclohexyl bromide primarily reacts with electro-generated Co(Ⅰ)TPP via the production of the cyclohexyl radicals,has been proposed.

关 键 词：四苯基钴卟啉 电化学氧化还原 溴代环己烷 

分 类 号：O624.2[理学—有机化学] O643.12[理学—化学]