This award in the Inorganic, Bioinorganic, and Organometallic Chemistry Program supports research on electron transfer reactions by Dr. Thomas J. Meyer of the Chemistry Department, University of North Carolina at Chapel Hill. Metal-to-ligand charge transfer (MLCT) excited states of polypyridyl complexes in molecular assemblies will be studied in order to better understand the general phenomenon of photoinduced electron and energy transfer. Chromophore-quencher and ligand-bridged assemblies will be synthesized. These new assemblies will be designed for the investigation of the following: (a) novel photophysical phenomena particularly in the Marcus inverted region, including intramolecular competition, time delays, and multi-photon effects; (b) the role of new structural motifs, based on cis/trans isomerism at unsymmetrically substituted bipyridine ligands; (c) long-lived storage of photochemical redox equivalents through the use of bridging electron transfer ligands; and (d) photchemical energy conversion. Spectroscopic parameters will be used to calculate electron transfer rate constants. Investigation of the electronic properties of large molecules and associations of molecules, or assemblies, is ultimately aimed at development of molecular-level electronic devices. This research is relevant to photochemical energy conversion and information storage based on color changes. To develop this technology, movement of electrons over long distances and over long time scales must be better understood.
