Accession Number:
ADA235884
Title:
Dynamic Solvent Effects on Electron Transfer Rates in the Inverted Regime: Ultrafast Studies on the Betaines
Descriptive Note:
Technical rept.
Corporate Author:
MINNESOTA UNIV MINNEAPOLIS DEPT OF CHEMISTRY
Personal Author(s):
Report Date:
1991-05-06
Pagination or Media Count:
28.0
Abstract:
Transient pump-probe measurements have been made on Betaine-30, the solvent polarity probe. Betaine-30 is composed of organic donor and acceptor groups. The transient data has been analyzed to measure k sub et the electron transfer et rate constant, in polar solvents for this inverted regime et. The observed rate constant, in various polar solvents is as much as a factor of 100, 000 larger than is predicted by the standard, classical, implementation of the theory of Sumi and Marcus, using Kjaer and Ulstrups estimates for necessary parameters. In contrast, a quantum treatment of the vibrational modes by Jortner and Bixon, which includes the dynamic solvent effect, predicts that the rate should be approximately k sub et, JB1 tau sub s. This is close to the experimental results in typical polar aprotic solvents. The kinetic behavior of Betaine-30 in slowly relaxing solvents is shown to be in the diffusionless limit of the hybrid, generalized Sumi-MarcusJortner-Bixon picture.
Descriptors:
Subject Categories:
- Organic Chemistry
- Physical Chemistry
- Radiation and Nuclear Chemistry