University of Georgia Research Foundation, Inc. Athens United States
Metal-containing clusters produced in molecular beams were used to explore the fundamental interactions in nanocatalysis and nanocluster materials. To probe nanocatalysis, we studied metal-adsorbate complexes with mass-selected infrared photodissociation spectroscopy. These studies investigated the carbonyl complexes of Ag, Au, Pt, Co, V, Nb, Ta, as well as those for small oxides of vanadium. IR photodissociation spectroscopy determined of the number of ligands in the primary coordination sphere, the shift in ligandsolvent vibrations compared to the free molecule, the structural arrangement of the ligands, and the electronic spin state of the metal. To probe nanocluster structure, bonding and stability, metal oxide, carbide and silicide clusters with up to 50 atoms were investigated with mass-selected photodissociation and density functional theory. Studies were completed on the oxide clusters of vanadium, niobium, tantalum, chromium, iron, yttrium, and lanthanum, copper and gold carbides and silicon clusters with chromium and silver. Clusters were identified with special stability e.g., Cr4010 and oxidation states were found to be different e.g., iron from those for the common bulk oxides. Copper and gold-doped carbon clusters adopt both linear and cyclic structures.