9307382 Coucouvanis Professor Coucouvanis, of the University of Michigan, will explore synthetic inorganic chemistry with support from the Inorganic, Bioinorganic, and Organometallic Chemistry Program. His efforts will concentrate on five topics, all related by the presence of metal-sulfur bonds. 1) He will explore the synthesis of thio and oxo-thio complexes of Nb and Ta with inspiration largely from analogy with the chemistry of Mo and W. A major goal will be to generate hydrido-hydrosulfido complexes by addition of H2 across M=S bonds. 2) He will develop the catalytic degradation of SO2 by use of thiomolybdate complexes. 3) He will investigate the synthesis of catecholato sulfido complexes; this will entail introduction of the catecholato group through condensations with catechol, as well as reductive couplings of catecholato complexes. 4) He will synthesize complexes having sulfate and related tetrahedral anions as bridging ligands. In this class of compounds the anions bind simultaneously to four metal centers, and are assisted by hydrogen bonding from dimethylammonium cations. 5) He will design amphiphilic supramolecules that are based on semiquinones, transition metal centers, and heterometalic M4S4 cubanes. The objective here will be to obtain "molecular reactors" for the activation of N2, O2, and CO2. %%% An important component in the advance of basic chemistry is the ever-broadening scope of molecular architecture. This is best achieved through the efforts of synthetic chemists. A particularly fertile area of synthesis is in compounds that have both metal ions and sulfur atoms. Much has been learned of the simple compounds with iron, molybdenum, and tungsten. The present research will develop the basis for the chemistry of niobium and tantalum, and it will explore the synthesis of compounds that are larger and more complex. An important objective will be to synthesize compounds that combine the properties of divergent subgroups, so as to produce "molecular reactors". This work will incorporate ideas gleaned from the study of biological enzymes. ***
