The coordination chemistry of dinuclear cationic transition metal complexes of molybdenum and tungsten with formal charges of four to ten will be explored through synthesis and structural methods. Kinetic and mechanistic studies of ligand substitution reactions and the organometallic chemistry of dinuclear metal centers will be initiated. These results may differ substantially from the thoroughly investigated mononuclear complexes due to the influence of the metal-metal bond. Ordered assemblies such as liquid crystals and polymers formed by use of dinuclear metal multiple bonds as building blocks will be investigated, with emphasis on the controllable magnetic, optical, and electronic properties of these macromolecular systems. The dinuclear precursors have first ionization potentials that vary by two volts depending on metal and the substituents; these features should allow a large array of macromolecular systems with tunable electronic properties. %%% In this project in the Inorganic, Bioinorganic, and Organometallic Program of the Chemistry Division, Dr. Malcolm H. Chisholm of Indiana University will continue his studies of the rich chemistry of dinuclear complexes of molybdenum and tungsten. These molecules show considerable promise as homogeneous catalysts. In addition, they can be assembled under proper conditions to form liquid crystals and polymers that may have useful properties as new materials.
