9313797 Cotton This grant in the Inorganic, Bioinorganic, and Organometallic Chemistry Program supports research by Dr. F. Albert Cotton of the Chemistry Department, Texas A&M University, into the nature of metal-metal multiple bonding by transition metals. Compounds containing multiply bonded ruthenium and osmium are well known, but in these investigations some unusual compounds will be synthesized and characterized. The scope of multiple bond chemistry will be extended by synthesis of species containing V, Nb, Ta, Fe, Ir and Pt. For some of the metals more commonly associated with this type of bonding (Os, W, Re, Pt), new compounds in higher oxidation states will be investigated. In addition, the internal movement of metal-metal dimers within the confines of the ligand cage will be studied. Also to be prepared are oligomeric and polymeric compounds in which metal metal dimer units are linked by pi- electron containing species, in order to probe the magnetic and electronic interactions along the chain or within a sheet. In dimeric compounds which contain two transition metals bonded to each other, triple and quadruple bonds are sometimes observed. The goal of this research is to test whether this type of bonding is possible with certain metals or metals in higher oxidation states for which it has not previously been observed. Research in this area contributes to the basic understanding of bonding and reactivity in organometallic cluster molecules, which have been found to be important in catalyzing organic reactions. Additionally, understanding compounds of this type contributes to knowledge of some types of solid-state electronic and optical devices and some potential anti-tumor agents.
