Factors controlling photochemical cleavage of the energetically unfavorable Ph-Se bond of alkyl phenyl selenides

A significant amount of Se-Ph bond cleavage is found in addition to the normal alkyl-SePh bond cleavage, where the ratio is dependent on the wavelength of light, solvent viscosity and the structure of alkyl groups. The synthetic efficiency of the reactions of organoselenium compounds are enhanced by selecting suitable reaction conditions.