The relative quantum yields and chemical efficiencies of crystalline p, p'-disubstituted 1, 3- diphenyl-2-propanones with 4-MeO, 4-Me, 4-F, 4-CF3, and 3, 4-diMeO groups were determined by parallel irradiation of polycrystalline samples. Variations in quantum yields that span a factor of 4 are analyzed in terms of the effects of substituents on the stability of the benzylic radical. All solid-state reactions proceeded with 100% chemoselectivity and ...
