Photochemical reactions (λ irr= 254 nm) of substituted benzyldiphenylphosphine oxides 1a- e have been investigated in benzene and acetonitrile. α-Cleavage from the singlet excited state is proposed as the primary process, and products formed both before and after escape of the primary intermediates from the solvent cage result. Radicals 2 and 3 are observed by nanosecond flash photolysis following excitation of 1a at 266 nm in acetonitrile. Acetone ...
