二氯二氰基苯醌及其阴离子自交换电子转移反应的理论研究

Theoretical Studies on Self-exchange Electron Transfer Between 2,3-Dicyano-5,6-dichloro-p-benzoquinone and Its Radical Anion

基于非平衡溶剂化能的约束平衡方法和溶剂重组能的新表达式,实现了电子转移反应溶剂重组能的数值解,研究了二氯二氰基苯醌(DDQ)及其阴离子体系DDQ-之间的自交换电子转移反应.考虑了DDQ与DDQ-分子以平行方式形成受体-给体络合物时的两种构型.引入线性反应坐标,计算了该反应在不同溶剂中的溶剂重组能.基于两态变分模型得到了反应的电子耦合矩阵元.根据电子转移动力学模型,计算了该自交换电子转移反应的速率常数.

We studied the self-exchange electron transfer reaction between 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and its radical anion,on the basis of the non-equilibrium solvation theory in virtue of a constrained equilibrium state.Two different conformations of the parallel donor-acceptor complexes were considered.Using the new non-equilibrium solvation model combined with the linear reaction coordinate,we calculated the solvent reorganization energy in different solvents.The electronic coupling are obtained through the two-state model.The self-exchange electron transfer reaction rate constants in different solvents were calcu-lated and the results correlate well with the experimental values.