*** 9508744 KAUFFMAN In this project in the Experimental Physical Chemistry Program, John Kauffman of the University of Missouri, Columbia will use subpicosecond spectroscopic techniques to measure the Rotational Correlation Times of anthracene and stilbene probe molecules in a variety of pure and mixed supercritical fluids (SCF), including carbon dioxide, ethane, and carbon dioxide-ethanol mixtures. These investigations will provide valuable information concerning the solvation characteristics of the fluids. A second series of experiments will use an anthracene-dimethylaniline exciplex as a model system for reaction studies in supercritical fluids. Information from these studies will be used to test current theories of SCF solvation and clustering, determine the effects of solvent density, viscosity, polarity and inhomogeneities on solvation, and provide insight on the chemical reactivities in supercritical fluids. Supercritical Fluid carbon dioxide has tremendous potential as an environmentally benign solvent in which to perform chemical processes such as extractions and synthesis. In order to make use of this potential, a microscopic understanding of the solvent environment around a solute molecule and the influence of this solvation on chemical reactivities. Professor Kauffman's research will provide detailed information on both these topics and will test current theoretical models of supercritical fluid solvation. ***
