This award is the starter grant increment of Dr. Catalano's Postdoctoral Research Fellowship in Chemistry. A new class of tri- and tetrametallic complexes will be synthesized containing a multiple Group VI metal-metal bonded core bridged along the metal-metal axis by a bidentate ligand to one or more square planar transition metal complexes. The goals of the research are to explore the bonding interactions between the square planar metal and the multiply bonded core and to probe the chemical and photochemical reactivity of these assemblies. The research will employ standard inorganic synthetic techniques using known precursors and the resulting products will be characterized by single crystal x-ray diffraction, multinuclear NMR, absorbtion and emission spectroscopies and IR and Raman spectroscopy. %%% This research will lead to a fundamental understanding of the multiple metal-metal bond and its role in inorganic chemistry, photochemistry and catalysis.