This award in the Inorganic, Bioinorganic, and Organometallic Program supports the work of Drs. Scot E. Wherland, John P. Hunt, and Harold W. Dodgen of the Chemistry Department, Washington State University, for the study of the effect of pressure on electron transfer reactions in nonaqueous solutions. Specific systems chosen for study include metallocenes, a series of chromium isonitriles, and substitution-proof clathrochelates. The primary methods of investigation will be stopped-flow and NMR. In addition to pressure, temperature dependence, solvent variation, and ionic strength will be studied. Rate control by solvents or electron tunneling at low temperatures may be observed. %%% This project may increase understanding of the fundamental nature of oxidation-reduction reactions in nonaqueous media and influence theoretical development in this area. The results would also be useful for organometallic chemistry, catalytic reactions, and some biological processes involving cell membranes. An understanding of the role of solvents could lead to some control of reaction rates by solvent variation.