Effects of Pressure on the Thermal Back Electron Transfer in a Dibenzylbipyridinium Salt. Solvent Reorganizations and Dynamic Solvent Effects

Kinetic effects of pressure on a decay of a radical pair produced by UV irradiation of N,Nʹ-dibenzyl-4,4ʹ-bypyridinium dichloride were studied in acetonitrile (AN) and propylene carbonate (PC). Both in AN and PC, the process was accelerated by an increase in pressure indicating a considerable contraction of the solvation sphere during the activation. Furthermore, in PC, pressure-induced retardation was observed at P > 200 MPa and it was attributed to slow solvent thermal fluctuations at high pressures.