Franck-Condon Factor Free’ electron

In the previous section, we alluded to the Franck Condon factors (FCF) in controlling electron transfer rates. For this topic, detailed reviews of theory and experiment are provided elsewhere. In sum, it is now well known that the reaction free energy required to transfer charge can be reduced by the reaction free energy, AG°, as summarized in the famous Marcus equation AG = (AG° — where X, the reorganization energy, is related to the degree of... 

Due to the complicated kinetics for both processes no attempt was made in ref. 83 to treat the data quantitatively. It was estimated, however, that the back electron transfer reaction is slower by about 3 orders of magnitude than that of the forward electron transfer. At the same time, the free energy change for the forward reaction (AG° = - 0.4 eV) is smaller than that for the back electron transfer (AG° = — 1.7 eV). This decrease of the reaction rate at large exothermicity was attributed [83] to the decrease of the Franck-Condon factors with increasing J in the situation when J > Er (see Chap. 3, Sect. 5). 

Equations [41]-[50] provide an exact solution for the CT free energy surfaces and Franck-Condon factors of a two-state system in a condensed medium with quantum electronic and classical nuclear polarization fields. The derivation does not make any specific assumptions about the off-diagonal matrix elements of the Hamiltonian. It, therefore, includes the off-diagonal... 

The method of generating "free" electrons to study localization and solvation may well influence the results in the sense of "fine tuning", but not the coarse grained results. Here we refer to finite lifetimes of precursor states, autoionizing states, Franck-Condon factors and so forth (Kenney-Wallace,... 

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