Photoinduced electron transfer in polar solutions. 2. New aspects of the role of the solvent mode in electron-transfer processes in charge-recombination reactions and comparison with charge-separation reactions
Photoinduced electron transfer in polar solutions. 2. New aspects of the role of the solvent mode in electron-transfer processes in charge-recombination reactions and comparison with charge-separation reactions
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极性溶液中的光致电子转移。
DOI：
10.1021/j100268a020
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
N. Mataga
中科院分区：
文献类型：
--
作者：
T. Kakitani;N. Mataga
通过使用极性溶剂模式的一个新方面，即其振动频率在反应物的中性状态下比在带电状态下小得多，作者制定了电荷重组率。数值计算表明，在强极性溶剂中，溶剂模式显然拒绝贡献的Franck-Condon重叠。因此，电荷重组率几乎完全由分子内量子模式和电子供体与受体之间的电子相互作用的大小决定，分子内量子模式在分子与分子之间变化很大。在强极性溶剂中溶剂模式对Franck-Condon重叠几乎没有贡献的结果与以前研究的电荷分离反应形成了鲜明的对比。详细研究了在极性环境中电荷分离态的高产率和高稳定性的条件。其结果是，它已被发现的电荷分离和电荷重组率，分别对能隙的弱和强的依赖性，这已被证明是第一次通过引入溶剂模式的新方面，可以提供一个有效的光诱导电荷分离过程的有利条件。参考文献13篇，附图8幅。
By using a new aspect of the polar solvent mode, that is, that its vibrational frequency is much smaller in the neutral state of the reactants than in the charged state, the authors formulated the charge-recombination rate. Numerical calculations show that in strongly polar solvents, the solvent mode apparently refuses to contribute to the Franck-Condon overlap. As a result, the charge-recombination rate is determined almost exclusively by the intramolecular quantum mode, which varies considerably from molecule to molecule, and by the magnitude of the electronic interaction between the electron donor and acceptor. The result that the solvent mode scarcely contributes to the Franck-Condon overlap in strongly polar solvent is in a marked contrast to that of the charge-separation reaction investigated previously. The condition for the high yield and high stability of the charge-separated state in a polar environment is investigated in detail. As a result, it has been found that the weak and strong dependences of the charge-separation and the charge-recombination rates, respectively, upon the energy gap, which have been demonstrated for the first time by introducing the new aspect of the solvent mode, can afford a favorable condition for an efficient photoinduced charge-separation process. 13 references, 8 figures.