Magnetic Field Effect on the Radical Yield of Electron Transfer Reactions Between a Dye Triplet and Heavy Atom Substituted Electron Donors

Abstract

The radical yield in the electron transfer reactions between thionine triplet and various halo-genanilines, as measured by kinetic flash spectroscopy in the microsecond time region, decreases by application of magnetic fields up to 4 kGauss. The relative magnetic field effect parallels the influence of the heavy atom substituents on the intersystem Crossing rate constant in the triplet exciplex supposed to be the primary product of the electron transfer reaction. The magnetic field effect is suggested to be due to differences of the g-factors in the geminate radical pair, originating by dissociation of the triplet exciplex. © 1979, Walter de Gruyter. All rights reserved.