This Presidential Young Investigator award from the Inorganic, Bioinorganic and Organometallic Chemistry Program will support the research of Dr. Mercouri Kanatzidis on the chemistry of sulfur and selenium compounds of heavy metals. One facet of the research program will focus on the chemistry of ruthenium/ sulfur compounds, with the aim of attaining new insights into heterogeneous catalytic processes such as the hydrodesulfurization of petroleum by ruthenium disulfide. The second facet of the research program involves research at the interface of inorganic chemistry and materials science. The techniques of synthetic inorganic chemistry will be used to produce precursors to new materials, such as low dimensional intermetallic alloys. Anionic soluble clusters containing late transition and main group metals bridged by either selenium or tellurium will be formed in solution and then precipitated with heavy metals such as cadmium to form new solid compounds. An example of a substance synthesized in this manner has the composition Cd:Hg:Te = 1:1:8, and has potential applications in the area of low energy detection. Also to be explored are syntheses of metal/sulfur and metal/selenium compounds at high temperatures with molten salts as solvents. Of particular interest are compounds containing S-S or Se-Se bonds which can be reductively (and reversibly) cleaved electrochemically or by reaction with alkali metals. Such materials may be useful as cathodes for high energy density rechargeable batteries.