Reorganizational energy constants

This brings us to examine the formal resemblance and the conceptual difference between Eq. (12.9) and Sanderson s approximation [244,245]. The latter can be deduced from Eqs. (12.1) and (12.3) by redefining the reorganizational energies as A (K) — A (K )—an approach oblivious of the fact that K and K are not isoelec-tronic in most cases, but approximately valid as long as the CNE terms remain sufficiently small. The point is that Sanderson s formula, Dec = ecc + RE(K) - - RE(L), treats 8cc as a constant, which is not true. This simplifying hypothesis did not appear... 

Marcus described the solvent reorganizational energy (Xs) that accompanies the transfer of a charge of magnitude e in terms of the repolarization of a dielectric continuum (with index of refraction r] and static dielectric constant Dg) around two spherical reactants with radii a and b, separated a distance... 

In related model complex studies, Isied and coworkers, have examined photo-induced (or pulse-radiolytically initiated) electron-transfer processes in which a polypyridine-ruthenium(II) complex is linked by means of a 4-carboxylato,4 -methyl,2,2 -bipyridine ligand and a polyproline chain to a [Co(NH3)5] + or [(-NH-py)Ru (NH3)5] acceptor. Chains composed of from zero to six cis-prolines have been examined. The apparent distance dependence of the electron-transfer rate constant, corrected for variations in the solvent reorganizational energy, seems to exhibit two types of distance dependence, 0.7-1A for short chains and /3 a0.3 A for long chains. A very detailed theoretical analysis of electron transfer in the complexes with four proline linkers has indicated that the electronic coupling is sensitive to conformational variations within the proline chain. ... 

Figure 11 The variations of rate constants with changes in solvent reorganizational energy with D/A...

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