Pd-wire and Pd-ring structures on HOPG.

Nanostructure catalystThe use of molecular precursors allows decomposition and deposition of metallic particles at temperatures below the corresponding metalfusion point, leading to the formation of kinetic products. Oligonuclear, homo- and heterometallic, organosoluble pyrazolato complexes are prepared and characterized by standard, as well as crystallographic and electrochemical techniques. Homometallic Pd- complexes of different nuclearities have been shown to produce Pd-particles of different morphologies, upon reductive decomposition on solid supports. Trinuclear through hexanuclear Ag- and Au-pyrazolates are under investigation. A series of bimetallic-M/M' tri-, tetra- and hexanuclear complexes, where M = Pd, Pt and M' = Co, Cu, have been crystallographically characterized; their reductive decomposition under H2-gas of pre-organized structures on HOPG support produce alloy particles reflecting the stoichiometry of their molecular precursors. This project is currently supported through the NASA-funded Center for Nanoscale Materials (NASA Grant NCC3-1034).