电子转移反应中分子理论的溶剂自由能和外氛重组能

Solvent free energy and outer-sphere reorganization effect from molecular theory in electron transfer reaction

考虑到溶剂分子的非线性效应，应用Franck－Condon原理解释了外氛溶剂重组能；对电荷分离的反应，采用计算机模拟数据得到了一个合理的自由能计算模式，并用此模式计算了反应物和产物状态的重组能，结果表明，当能量差偏离平均值很远时，必须考虑自由能高次项的修正，即溶剂分子的非线性效应．对溶剂重组能效应的物理意义、反应物和产物状态之间重组能差别的原因进行了讨论．

Considering the nonlinear response of the solvent moforules in a new way,the authors derive an explicit expression fdr the outer-sphere solvent reorganization energy and its validity is verified by using Franck-Condon principle. A reasonable free energy diagram is constructed arid the reorganization energies for the reactant product states are calculated respectively. The resuIts show that the higher term correction of the free energy,i. e. the nonlinear effects of the solvent,is necessary to be considered when the energy gap deviates far from its mean value. The physical significance of the solvent reorganization effect and some consequences for the difference of the reorganization energy between the reactant and product states are investigated.