This award from the Chemistry Research Instrumentation and Facilities Program will assist the Department of Chemistry at University of Rochester in the purchase of a modern single drystal diffraction system. This new instrumentation will enhance greatly research in a number of areas including the following: (1) Studies of C-H and C-S bond activation in thiophenes; (2) The catalysis of acyl-acyl coupling reactions with binuclear platinum group complexes; (3) Electrophilic and radical processes in bond activation using cationic complexes of Rh(III) and Ir(III) and d7 complexes; (4) Studies of the formation of aggregates and microcrystallites of various dyes and photochemically reactive chromophores; (5) The development of asymmetric synthesis methodology for natural products; and (6) The design and synthesis of catalysts for the polymerization of monosubstituted olefins. The X-ray diffractometer is used to make accurate and precise measurements of the full three- dimensional structure of a molecule. The information obtained gives the precise values of all the bond distances and bond angles of a given molecule and it gives accurate information about the spatial arrangement of that molecule relative to the neighboring molecules.