Design of luminescent polynuclear copper(I) and silver(I) complexes with chalcogenides and acetylides as the bridging ligands

A number of chalcogenido and alkynyl clusters of copper(I) and silver(I) with various nuclearities have been synthesized and characterized. All these clusters have been found to possess rich photophysical and photochemical properties. The phosphorescent states of the complexes have been shown to undergo facile photo-induced oxidative electron-transfer quenching reactions with a series of pyridinium acceptors, indicative of their highly reducing nature in the excited states. The lowest lying excited states of the clusters have been assigned to be an admixture of ligand-to-metal charge-transfer (LMCT) and metal-centred (d-s) transitions, which have also been supported by Fenske-Hall and ab initio molecular orbital calculations. The excited state properties of these clusters have also been probed by nanosecond laser flash photolysis studies. © 1998 Elsevier Science S.A.