This award in the Inorganic, Bioinorganic, and Organometallic Program supports research by Dr. James N. Demas of the Department of Chemistry, University of Virginia, on interaction of luminescent Ru(II), Os(II), Ir(III), and Re(I) photosensitizers with various environments. The work will be carried out with collaborator Dr. Benjamin A. DeGraaf of the Chemistry Department, James Madison University. The long-term goal is to understand the effect that attachment to biopolymers, vesicles, organic polymers, cyclodextrin, DNA, and other organized media has on the luminescent properties of these complexes. Of particular interest is testing the suitability of these complexes with long- lived excited state lifetimes for detecting processes such as association and folding of proteins. Long alkyl chains will be attached to the metal complexes in order to modify the behavior of the luminescent portion of the molecule as a consequence of placing hydrophobic interactions in the vicinity of the metal. Factors such as temperature and media dynamics would be considered. The project will require synthesis of a number of new complexes and use of advanced luminescence methods, such as dynamic polarization and phase fluorimetry measurements. This research could be aid in the design of highly sensitive luminescent materials to selectively identify certain structural features or to serve as sensors or detectors. Selective and sensitive probes for molecular-level structural features and changes in macromolecules are needed for biological, environmental, and industrial applications. For example, reactions of enzymes, catalysts, and gas molecules at surfaces are known be very sensitive to structural and solvent environment. In this research, the luminescent property of certain metal complexes will be tested as a probe for structural changes in proteins, in order to obtain information necessary for the design of effective molecular probes.
