Photochemistry and photophysics of coordination compounds: An extended view

Coordination chemistry is much more than the coordination of transition-metal ions by organic or inorganic ligands. Its scope extends to the binding of all kinds of substrates (cationic, anionic, and neutral molecular species). Therefore coordination chemistry merges into the big field of supramolecular chemistry. Coordination compounds (with or without metals) exhibit by definition a high level of organization and therefore they are quite suitable to exploit the energy and information content of photons. In this paper we illustrate specific examples concerning the similarity between the photochemical behavior of classical coordination compounds (i.e. metal complexes) and supramolecular species not containing metals. We also describe coordination compounds not containing metals that undergo photochemically, electrochemically, or chemically induced mechanical movements (molecular-level machines) and behave as logic gates. (C) 1998 Elsevier Science S.A.