Mechanisms in sensitized photochemistry of environmental chemicals

Abstract

Abstract This review consists of three main parts. After a short discussion of the theory of photochemistry, the three major mechanisms (radiative, short range and long range) for the transfer of electronic excitation energy from sensitizers (donors) to substrates (acceptors) are described. Criteria for the selection of. sensitizers are a high efficiency of intersystem crossing (in the case of triplet sensitization) and energy transfer, and strong absorption at wavelengths longer than those at which the acceptor absorbs. Two mechanisms of sensitized photo‐oxygenation, viz. the radical and singlet oxygen type, are discussed. The second part of this review deals with photosensitizers, with a strong emphasis on compounds of importance in environmental photochemistry on the one hand and those interesting from a mechanistic point of view on the other. The third part describes photo‐inducers and their role in photoreactions. Additional literature references (to January 1978) are presented at the end of this review.