The influence of ST −1 mixing in spectra which exhibit electron spin polarization (CIDEP) from the radical pair mechanism

Abstract

The effect of ST −1 coupling on the intensities in the electron spin resonance spectra of spin-polarized radicals is discussed, and demonstrated in spectra with many hyperfine components for the first time. Both hyperfine-dependent and hyperfine-independent contributions to the polarization occur; the latter could easily be mis-assigned to the action of the triplet mechanism. The effects are demonstrated in radicals produced on photolysis of acetone, both in the presence of diethyl phosphite and in propan-2-ol solution at low temperatures.