Light induced electron transfer of metal complexes has been studied extensively during
the last decade. This interest was stimulated by attempts to develop an artificial photosynthesis
for the conversion and chemical storage of solar energy. Even if this goal has not yet
been achieved photochemical redox processes of coordination compounds are now much
better understood. In this review the various possibilities of photoinduced electron transfer
are discussed and illustrated by selected examples. A distinction is made between intra- and
intermolecular electron transfer which may occur as a direct optical transition or by an excited
state electron transfer mechanism.