Photochemistry and photophysics of transition-metal complexes

This chapter aims to cover important developments on the photophysical and photochemical properties of transition-metal complexes for the period between June 2004 and July 2007. Because of the enormous number of systems investigated, I was compelled to leave articles with strongly applied character out of this overview, which is mainly focused on fundamental aspects of metal complexes also as units of supramolecular assemblies. For the same reason, I could report only on good impact factor articles. A great number of the considered works concern photoinduced electron (PET) and energy (PEnT) transfer studies in mononuclear compounds and multicomponent arrays. An important purpose of these articles is the possibility to obtain intensely phosphorescent systems and long-lived charge-separated states, in view of their possible interest in the development of luminescent materials, light emitting diodes, sensors, solar cells, artificial photosynthetic systems. A non-negligible number of articles (about 20%) deal with the excited-state redox activity of transition-metal compounds. In this field, particular attention is devoted to the photocatalytic functionalization of organic substrates, to environment decontamination and to CO₂ reduction.