This Research in Primarily Undergraduate Institutions (PUI) project is in the general area of analytical and surface chemistry and in the subfield of bioelectrochemistry. The goal of this innovative program is to characterize the electrochemical behavior of transition metal complexes that experience a large change in molecular structure during electron transfer. Experimental results from this research will be used to test current theories of electron transfer reactions and to understand examples of unusual redox behavior associated with structural change. Rates and mechanisms of electrode reactions will be investigated using dynamic voltammetric techniques, low temperature electrochemistry, and microelectrodes. X-ray absorption fine structure (EXAFS) spectroelectrochemistry will be used to determine changes in metal-ligand bond distances that occur as a result of electron transfer. Compounds to be investigated include oxomolybdenum (VI) complexes, axially substituted iron porphyrins and cobalt macrocycles, metal-metal bonded dimers of molybdenum and tungsten, and the iron-molybdenum cofactor extracted from nitrogenase enzyme. The results of these investigations should contribute significantly to our understanding of metalloenzyme-catalyzed electron transfer reactions and have relevance to both biotechnological and in vivo processes.
