Contribution of spin-orbit interaction in the recombination process of radical pair produced in photoreduction of benzophenone derivatives in SDS micellar solution

摘要

The recombination mechanism of intermediate radical pairs produced in the photoreduction of benzophenone and its halogen-substituted derivatives in an SDS micellar solution was studied by the pulse-mode product-yield-detected ESR method. The rateof recombination from the triplet state, which is caused by the spin-orbit interaction, was obtained by the simulation of the spin adduct yield as a function of the delay period in the pulse-PYESR experiments. The rate of "intersystem recombination" wasconsiderable for the system with a bromine-substituted benzophenone, but that for a chlorine-substituted benzophenone was negligible. These results were explained with a simple theoretical model.