MAGNETIC-FIELD EFFECT ON THE DYNAMIC BEHAVIOR OF A RADICAL PAIR INVOLVING AN SN-CENTERED RADICAL

The photoreduction of xanthone with triethyltinhydride in a sodium dod ecylsulfate solution was investigated with the aid of a time-resolved ESR and a nanosecond laser flash photolysis. Upon irradiation of xanth one with triethyltinhydride, the hydrogen abstraction occurred and the ketyl-type and cyclohexadienyl-type radicals were observed by CIDEP s pectra. The escaped xanthone ketyl radical increased with increasing m agnetic field strength up to 1.29 T. The observed magnetic filed effec ts can be interpreted by a combination of the hyperfine coupling and t he relaxation mechanisms in the case of a triplet radical pair.