Linear response in theory of electron transfer reactions as an alternative to the molecular harmonic oscillator model
Linear response in theory of electron transfer reactions as an alternative to the molecular harmonic oscillator model
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DOI：
10.1063/1.478425
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发表时间：
1999-03-15
影响因子：
4.4
通讯作者：
Marcus, RA
中科院分区：
文献类型：
--
作者：
Georgievskii, Y;Hsu, CP;Marcus, RA
采用线性响应理论和二阶累积展开法研究了溶剂波动对电子转移反应速率的影响。得到的速率常数的表达式在溶剂的介电响应函数。它表明，从而，这个表达式，这通常是使用分子谐振子（“自旋玻色子”）模型推导出来的，是有效的，不仅近似谐波系统，如固体，但也为强分子非谐系统，如极性溶剂。推导是一个相对简单的替代一个基于量子场论技术。现在还包括由于溶质分子的存在而导致的系统不均匀性的影响。给出了一个表达式，它把重组自由能与两个假设系统的自由能差联系起来的静电结果的类似物推广到频率空间和量子力学[J. Chem. Phys. 39，1734（1963）]。后者的表达已在适应特定的静电模型在文献中的电子转移问题是有用的，本扩展可以预期有类似的效用。(C)1999年美国物理学会。[S0021-9606（99）01511-1]。
The effect of solvent fluctuations on the rate of electron transfer reactions is considered using linear response theory and a second-order cumulant expansion. An expression is obtained for the rate constant in terms of the dielectric response function of the solvent. It is shown thereby that this expression, which is usually derived using a molecular harmonic oscillator ("spin-boson'') model, is valid not only for approximately harmonic systems such as solids but also for strongly molecularly anharmonic systems such as polar solvents. The derivation is a relatively simple alternative to one based on quantum field theoretic techniques. The effect of system inhomogeneity due to the presence of the solute molecule is also now included. An expression is given generalizing to frequency space and quantum mechanically the analogue of an electrostatic result relating the reorganization free energy to the free energy difference of two hypothetical systems [J. Chem. Phys. 39, 1734 (1963)]. The latter expression has been useful in adapting specific electrostatic models in the literature to electron transfer problems, and the present extension can be expected to have a similar utility. (C) 1999 American Institute of Physics. [S0021-9606(99)01511-1].