Homogeneous photo catalysis by transition metal complexes

The photochemistry of coordination compounds has become an increasingly popular technique for controlling and tuning the reactivity of transition metal complexes and organometallic compounds as well. Rather uncommon reaction pathways can be initiated by electronic excitation of diverse spectroscopic states of these compounds. Besides stoichiometric electron-transfer, dissociation, substitution as well as rearrangement reactions induced by light, photocatalytic processes and photoinduced chain reactions are of particular significance. Examples of photoinduced catalytic and photoassisted reactions as well as photoinduced chain processes will be reviewed to illustrate the advantages of such reaction pathways. Particular attention is given to the spectral sensitization of photocatalytic systems. A summarizing evaluation as well as perspectives for future developments are given. (C) 1999 Elsevier Science S.A. All rights reserved.