Solvent and Temperature Effects in the Photoreduction of Ketones

Abstract The dependence of the quantum yield of photoreduction on solvent polarity and on temperature has been investigated for a number of substituted aromatic ketones. An interpretation in terms of the dipole moments in excited states to account for the solvent effect is discussed. From the temperature effect it is suggested that the different reactivities of n –π*, π–π*, and CT states is related to an activation energy.