文献类型：期刊文献

中文题名：生物醌分子伏安响应的多电子转移辨析

英文题名：Resolve Mono-Electronic Process in the Voltammetric Behaviors of Multi-Redox Bis-Coenzyme Q_0

作者：周浩[1];龙亿涛[1]

机构：[1]华东理工大学结构可控先进功能材料及其制备教育部重点实验室,上海200237

年份：2014

卷号：20

期号：6

起止页码：533

中文期刊名：电化学

外文期刊名：Journal of Electrochemistry

收录：CSTPCD;;北大核心:【北大核心2011】；CSCD:【CSCD_E2013_2014】；

基金：国家杰出青年基金(No.21125522);上海高校特聘教授(东方学者;跟踪计划)资助

语种：中文

中文关键词：辅酶Q0;电子相互作用;方波伏安法;多电子转移;分峰;单电子响应辨析

外文关键词：coenzyme Q0; electron communication; square-wave voltammetry; multi-electron transfer; mono-electronic discrimination

摘要：电化学反应中,一个基元电子转移反应仅对应一个电子交换,实际上多电子转移反应也涉及对应数目的单电子转移步骤,分离、辨析每个电子基元反应的氧化还原峰电位十分重要.本文以辅酶Q0(Co Q0)、亚甲基桥连双辅酶Q0(Bis-Co Q0)为模型,采用循环伏安和方波伏安技术研究其电化学特性,提出了一种应用于多电子转移体系、分析单个电子转移电位的方法.实验表明,Co Q0经历两步单电子还原反应.Bis-Co Q0中两个醌单元发生强电子相互作用,电极过程为4电子多步转移.对于表观上的4电子"三步"转移反应,拟用Lorentzian-Gaussian分峰拟合Co Q0和Bis-Co Q0体系方波伏安响应曲线,分别获取每个电子转移步骤的电位,进一步证明Bis-Co Q0经历四分步单电子转移反应,为热力学研究提供更多信息.
A widely held concept in electrochemistry is that truly elementary electron-transfer reactions always involve the exchange of one electron, therefore, an overall process involving a change of n electrons must involve n distinct electron-transfer steps. It is highly desirable to resolve multiple-step electron transfer reactions into each electron transfer step. The electrochemical behaviors of coenzyme Qo and methylene-bridged bis-coenzyme Q0 were investigated by cyclic voltammetry and square wave voltammetry in nonaqueous dichloromethane containing 0.15 mol· L^-1 Bu4NClO4 as the supporting electrolyte. The redox reaction of coenzyme Q0 is well described as two chemically reversible one-electron reduction processes. Bis-coenzyme Q0 exhibits three redox waves in voltammetric experiment, as two bridged coenzyme Q0 units show strong intramolecular electron communication. Experimental data were curve fitted with a Gaussian and Lorentzian mixed product function after subtracting the Shirley background. Results show that four-electron reduction of his-coenzyme Q0 is preceded by stepwise pathways, defining as four successive, mono-electronic electron-transfer steps.