With this award from the Inorganic, Bioinorganic and Organometallic Chemistry Program Dr. Joseph T. Hupp will assess the various factors which govern the light-induced transfer of electrons between the metal centers in molecules which contain two metal atoms. The information to be gained will provide a deeper understanding of processes which are important in the conversion of light energy to chemical energy and in biological electron transfer. The goal of the project is to assess directly various superexchange contributions to intervalence charge-transfer reactions in bimetallic complexes. The modulation of electronic interactions by changes in distance, temperature, solvent and external orbitals will be investigated. The experimental strategy will involve the synthesis of a variety of new polypyridyl ligands designed to modulate the distance of separation of the two metals, and of a variety of new bifunctional crown ether-containing ligands designed to modulate intervalence charge transfer by forming inclusion complexes with either aromatic molecules or with simple closed-shell cations.
