This grant in the Inorganic, Bioinorganic, and Organometallic Program will enable Dr. Joseph W. Bruno of the Chemistry Department of Wesleyan University to study the mechanism of reactions of ketene complexes, using complexes in which an unsymmetrically substituted heteroallene is bound to the metal. Four reactions will be investigated: (1) cleavage of the C-O bond in coordinated ketenes; (2) intramolecular isomerization of ketenimines and ketenimidates; (3) reversible C-C cleavage of coordinated ketones; and (4) stereoselective addition to coordinated ketenes. These studies have relevance to Fischer-Tropsch chemistry, industrial processes which utilize syn-gas (carbon monoxide and hydrogen) to produce a variety of hydrocarbons, alcohols, aldehydes, esters, and ketones. Dr. Bruno has previously prepared vanadocene and niobocene ketene-hydride or ketene-alkyl compounds which are anticipated to undergo bimolecular eliminations with early transition metal alkyls, hydrides or amides. The resulting species are expected to exhibit ketene C-O cleavage reactions to produce oxo-vinylidene species. In the ketenimine project, emphasis will be placed on determining the bonding mode of the intermediate in isomerization reactions. During the C-C cleavage reactions of coordinated ketones, formation of metallaenolate has been suspected. Spectroelectrochemistry techniques will be used to confirm the presence of this species. In the last project, cyclopentadienylmanganese complexes will be studied.
