Bioorganometallic Catalysts: Strategies for Synthesis, Immobilization and Applications

Texas A&M Research Foundation, College Station TX

Investigators

Abstract

This award in the Inorganic, Bioinorganic and Organometallic Chemistry program supports research by Professor Marcetta Y. Darensbourg at Texas A&M University to pursue a new paradigm for enzyme active site construction derived from the active site of the enzyme Acetyl CoA Synthase and to develop NiN2S2 and other MN2S2 complexes as a new class of ligands that support organometallic chemistry. The basic hypothesis is that the binuclear makeup of the active sites may be interpreted in terms of metal-dithiolates as ligands to a second, catalytically active metal. Through these derivatives the electronic and steric characteristics of neutral and anionic NiN2S2 metalloligands are to be established via CO vibrational spectroscopy and solid state structures, respectively. Fundamental organometallic reactions in C-C coupling catalytic processes of the Rh(I) and Pd(II) compounds will be delineated through the study of reactions pertinent to CO/olefin co-polymerization (NiN2S2-Pd(II)(Me)2) and hydroformylation (NiN2S2-Rh(I)(CO)2). One aim focuses on hydrogenase model complexes designed in accord with computational studies in collaboration with Prof. Michael B. Hall and tested for hydrogenase-like function of H2 production and H2 activation. Another aim is to use the ligating ability of Ni(CGC) complex to anchor reactive organometallics on resin beads for the purpose of gaining the advantages of heterogenizing and site separation of reactive organometallics prone to aggregation and deactivation. This research uses synthetic models of complex reaction sites in enzymes to create new catalysts. Graduate students will work at the interface of inorganic/organometallic chemistry and biology and are also engaged in mentoring and out-reach activities.