Extension of Hopfield鈥檚 Electron Transfer Model To Accommodate Site鈥揝ite Correlation

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• 作者：Marshall D. Newton
• 刊名：Journal of Physical Chemistry B
• 出版年：2015
• 出版时间：November 19, 2015
• 年：2015
• 卷：119
• 期：46
• 页码：14728-14737
• 全文大小：430K
• ISSN：1520-5207

文摘

Extension of the F枚rster analogue for the ET rate constant (based on virtual intermediate electron detachment or attachment states) with inclusion of site鈥搒ite correlation due to coulomb terms associated with solvent reorganization energy and the driving force, has been developed and illustrated for a simple three-state, two-mode model. The model is applicable to charge separation (CS), recombination (CR), and shift (CSh) ET processes, with or without an intervening bridge. The model provides a unified perspective on the role of virtual intermediate states in accounting for the thermal Franck鈥揅ondon weighted density of states (FCWD), the gaps controlling superexchange coupling, and mean absolute redox potentials, with full accommodation of site鈥搒ite coulomb interactions. Two types of correlation have been analyzed: aside from the site鈥搒ite correlation due to coulomb interactions, we have emphasized the intrinsic 鈥渘onorthogonality鈥?which generally pertains to reaction coordinates (RCs) for different ET processes involving multiple electronic states, as may be expressed by suitably defined direction cosines (cos(胃)). A pair of RCs may be nonorthogonal even when the site鈥搒ite coulomb correlations are absent. While different RCs are linearly independent in the mathematical sense for all 胃 鈮?0掳, they are independent in the sense of being 鈥渦ncorrelated鈥?only in the limit of orthogonality (胃 = 90掳). Application to more than two coordinates is straightforward and may include both discrete and continuum contributions.