This project in the Inorganic, Bioinorganic and Organometallic Chemistry Program is in the area of bioinorganic chemistry. The focus of the project is nonbiological metal-containing compounds which mimick the action of monooxygenase enzymes. These enzymes, which catalyze the incorporation of oxygen atoms from dioxygen into organic substrates, contain metal ions at their active sites, principally heme iron, non-heme iron and copper. The mechanisms of the reactions of these enzymes are not understood, and it has not been possible thus far to duplicate their reactivities with nonbiological reagents. In an effort to develop "reaction analogies" to the monooxygenase enzymes, reactions of metalloporphyrin peroxo complexes are being studied to learn more about the role of the O-O bond cleavage step in the heme enzymes. To mimick the action of non-heme enzymes, where much less is known about the environment of the metal at the active site, metal-mediated oxygen atom transfer from the single oxygen atom donor iodosylbenzene to organic substrates is under investigation. Also under study are iron-mediated oxygenation reactions using reagents containing intact O-O bonds, i.e. dioxygen, superoxide and peroxide. The results of this research will provide information useful in assessing mechanisms of dioxygen activation in biological systems and in designing catalysts for oxygenation reactions for use in the laboratory and in industrial applications.
