The California Institute of Technology - 1985
Baylor University - 1981
Union Carbide Corporation
South Charleston, WV - 1986
Assistant Professor of Chemistry
Baylor University - 1993-2001
Associate Professor of Chemistry
Baylor University - 2001 -
My research group works in the general area of organometallic electrochemistry. Specifically, students in my group use electroanalytical techniques to study the oxidation or reduction, and succeeding chemical reactions, of transition metal organometallic compounds. The techniques used include cyclic voltammetry to measure formal potentials, controlled potential electrolysis to measure the number of electrons transferred, chronoamperometry and chronocoulometry to investigate kinetics, and spectroelectrochemistry to monitor changes in the IR spectra of the complexes upon oxidation or reduction. All projects begin with the synthesis of one ore more starting organometallic complexes, generally under inert atmosphere conditions. Once some information has been gained about their redox reactivity through electroanalytical techniques, synthetic reactions are performed and the products are characterized through spectroscopic techniques including IR, NMR, and X-ray crystallography.
Information gained through electroanalytical studies and characterization of the products of redox reactions allows us to postulate mechanisms for the electron transfer induced reactions of organometallic compounds. For example, we have studied the oxidative cleavage of the Mo-Hg bonds in the linear trimetallic complex [CpMo(CO)2PPh3]2Hg. Through a surprisingly complex series of reactions this compound is oxidized by two electrons to two 16-electron molybdenum fragments and metallic mercury. Likewise, the reduction of the complex (C7H7)Mo(CO)2C6F5 is not as simple as one might anticipate. After an initial one-electron transfer, the complex dimerizes though coupling of the cycloheptatrienyl rings. The resulting bitropyl complex can be reoxidized to return the monomeric starting material or it may react with ligands such as trimethylphosphite to displace the bitropyl and produce Mo(0) complexes with their own unique redox and substitution chemistries. In general, electron transfer to or from transition metal organometallic compounds makes them very reactive. The products of these reactions are often unusual and so open up new fields of study. The information we gather through the study of the redox reactivity of these complexes may someday have an impact on the homogeneous catalysis of reactions such as carbonylation, hydrogenation, and polymerization.