Photoinduced energy-transfer dynamics in multichromophoric arrays containing transition metal complexes and organic modules

Transfer of excitation energy in natural systems is a fundamental process for light harvesting and propagation of information. The deep understanding of the energy transfer mechanisms and of the strategies for governing the directionality of the energy flow in artificial multichromophoric arrays is at the basis of their use in demanding fields such as solar energy conversion and optoelectronic applications. This review describes the recent activity of the authors in the synthesis and photophysical characterization of supramolecular arrays containing transition metal polypyridine complexes and organic units, with attention on the mechanisms and the pathways of the energy transfer processes that occur in the arrays. A topic of interest has been the exploitation of antenna effects as well as energy conduction in molecular wires. The design of the systems took into consideration several aspects that need to be balanced in the construction of efficient and useful arrays, in particular the spatial displacement of the units, their energy content distribution and the nature of the linkers that connect them. The latter point was of great relevance and the most recent studies afforded the preparation and the analysis of systems where the ligand is a large aromatic unit, that can both provide a structural role, a suitable electronic communication between the chromophores and an additional photoactive partnership. (C) 2012 Elsevier B.V. All rights reserved.