The Photochemistry of Aryl Halides and Related Compounds

Abstract

Publisher Summary This chapter discusses the photochemistry of aryl halides and related compounds. Due to the widespread use of substituted aryl halides as pesticides, electrical insulators, moth proofing agents, etc. and the environmental problems which the use of these compounds pose, it seems worthwhile reconsidering the photochemistry of these compounds. Furthermore, the photoinduced decomposition of aryl halides is used extensively in synthesis, and much of this latter work has been recently reviewed. It is well established that on photolysis, many aryl halides undergo homolysis to generate aryl radicals and halogen atoms. The question as to whether the excited singlet or triplet state or indeed both excited states are responsible for reaction, is of considerable importance. Thus, if reaction occurs from the excited singlet state, the homolytic process may well be in competition with an electrocyclic reaction. The precise mechanism for photoinduced homolysis of aryl-halogen compounds is dependent upon both the nature of the halogen substituent and the aryl group.