CAREER: Roles of Transition Metals in Dioxygen Activation and Superoxide Scavenging

Johns Hopkins University, Baltimore MD

Investigators

Abstract

This CAREER award in the Inorganic, Bioinorganic and Organometallic Chemistry program supports work by Professor Justine Roth at Johns Hopkins University to probe the interaction of O2 with transition metals via the determination of oxygen isotope effects. Measurements of the variation in O-16 and O-18 ratios from natural abundance will reveal thermodynamic and kinetic factors that play a role in the interaction of dioxygen with transition metal reagents. Changes in oxygen bonding during redox processes are important in industrial oxidations and in biological utilzation of O2 as an energy source. The properties of metal-O2 adducts will be investigated, and electrochemical data will be gathered to address the ability of these species to carry out C-H and O-H oxidations. Correlations between driving-force and rate will be explored for electron, proton and hydrogen atom transfer reactions. An intensive mentoring program for middle school aged females in Baltimore will build on summer workshops associated with the Maryland Science Center. After two years of centering the workshops on demonstrations, the third year will focus on crafting a biotechnology display for the science center. Oxidation processes are important in biological systems and in industrial settings. The mechanism of elemental dioxygen interacting with transition metal complexes is relevant to large scale chemistry and biochemistry. Comparing kinetic and equilibrium distributions of oxygen isotopes will provide insight into the bonding changes that accompany activation and incorporation of oxygen into metal complexes and organic substrates.