Dr. William B. Euler of the Department of Chemistry, University of Rhode Island, is supported by the Inorganic, Bioinorganic, and Organometallic Chemistry Program to study polymers of mixed-valence ruthenium azine complexes. This project involves the synthesis and characterization of new ruthenium-polyazine based polymers in order to determine the role of the metal in the electronic and charge-transfer properties of the polymers. Systems selected will incorporate the ruthenium center as part of the conjugated electron-transfer pathway. The charge-transfer properties of the polymers will be modified by changing the length of the oligoazine bridge portion of the polymer ligand and thus the distance between ruthenium sites. A theoretical model predicts that as the metal sites become further apart, the coupling between metals will increase, up to the limit of the conjugation length of the oligoazine. Binuclear ruthenium-oligoazine-ruthenium compounds will also be prepared and studied as models for understanding this unusual predicted property of the polymers. All of the new materials will be studied by infrared, nuclear magnetic resonance, and ultraviolet-visible-near-infrared spectroscopies, cyclic voltammetry, and variable temperature electrical conductivity measurements. In this project the use of metal compounds appended to electrical conducting polymers is expected to modify the polymer properties, allowing for the creation of new nonlinear optical materials, catalysts, and nanostructured materials. The polymers to be studied will also help in the fundamental understanding of the transfer of electrons through proteins, an important problem in biological chemistry.
