Stephen Kukolich of The University of Arizona is supported by the Experimental Physical Chemistry Program to perform high resolution fourier-transform microwave (FTMW) spectroscopic studies of transition (TM) hydrides, metal-olefin complexes, non-rigid complexes, dinuclear complexes and organometallic radicals. In the first case, TM complexes containing two hydrogen atoms will be investigated, with an eye towards distinguishing between `dihydrogen` complexes (the hydrogen-hydrogen bond remains intact) versus dihydrides (hydrogen atoms bond independently to the metal, and are separated by much larger distances). Data will be analyzed to provide information on the three-dimensional structures, internal motion, quadrupole coupling constants and dipole moments of the molecules under study. Most of the systems that will be investigated were chosen to help in modeling and understanding the chemistry and interactions of transition metals in catalytic and enzyme systems. Metal hydrides are often quite reactive and play important roles in many industrial processes. The electronic and structural changes in olefins on complexation to metals play an important part in catalytic processes. Efficient production of a large fraction of industrial chemicals depends on one or more catalytic processes. The active sites of many enzymes which are essential for living systems involve various transition metal complexes.
