Molecular Solvent-Dynamical Effects on Activated Electron-Transfer Kinetics: How Important is Solvent Friction
Abstract
The likely extent of retardation exerted by solvent friction upon the rates of activated electron-transfer (ET) processes is explored and evaluated with reference to some extent solvent-dependent data for metallocene ET self exchanges. Barrier-crossing frequencies extracted from the experimental kinetic and barrier data for suitably adiabatic reactions are compared with solvent inertial frequencies (i.e. the zero-friction limit) as estimated from currently available analytic expressions. The additional extent of rate retardation seen in going from low-friction to ostensibly strongly overdamped solvents as deduced in this manner is seen to be substantially muted in comparison with the predictions of conventional Debye-continuum approaches, although follows a solvent functionality that is nevertheless roughly in accord with the latter. The likely importance of more rapid dynamics associated with short-range (molecular) solvation is addressed in the light of these findings. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1993
- Accession Number
- ADA265886
Entities
People
- Michael J. Weaver
Organizations
- Purdue University