This award supports cooperative research between Dr. Thomas Meyer of the University of North Carolina at Chapel Hill and Dr. Richard Keene at James Cook University, Townsville, Australia. This project will extend and broaden an NSF-supported research program in which the study of chromophore-quencher (C-Q) complexes of ruthenium and rhenium is intended to advance basic understanding of photoinduced electron-transfer processes. For example, it was shown that optical excitation to a metal-to-ligand charge transfer (MLCT) state in one ruthenium complex led to reductive quenching via intramolecular electron transfer. The study showed that MLCT excited states of ruthenium and rhenium complexes could be used successfully in the study of photochemically induced electron and energy reactions. The major objective of this U.S.-Australian cooperative project is the preparation and photophysical study of ruthenium in which electron transfer donors and acceptors are chemically attached to MLCT chromophores. To advance this area of study, new ligands will be designed in which spatial control of electron transfer can be achieved in order to maximize the efficiencies of formation and the lifetime of redox separated states. The project represents excellent collaboration between the Keene group (synthetic methodology for ligand modification) and the Meyer group (photophysical studies). This is important fundamental work in establishing new photochemical electron transfer systems and discovering new processes of energy and electron transfer.
