Educational Background:

Ph.D., Stanford University, 2001 B.S., Southwestern University, 1995

Awards:

• SLAC Employee Recognition Award, 2007 • Southwestern University Academic Scholarship, 1991-1995 • National Science Foundation REU Fellowships, 1993 and 1994

Research Description:

Metalloenzymes are Nature's catalysts and are able to carry out remarkably difficult chemical transformations which often pose significant challenges in a laboratory setting (including the need for high temperatures, high pressures, and complex synthetic procedures). These enzymatic catalysts include nitrogenase (which converts dinitrogen to ammonia), the oxygen-evolving complex in photosystem II, and methane monooxygenase (which converts methane to methanol). In all these examples, a metal-based active site is the center of catalytic activity; and it is these transition metal active sites which have provided much inspiration for biomimetic model chemistry and for homogeneous catalysis, and are the focus of our research program.

We are interested in development and application of X-ray based spectroscopies as probes of electronic structure in biological and chemical catalysis. We study both enzyme systems and small molecule model complexes, which aim to mimic the enzyme activity. In particular, we are interested in the development of new spectroscopic methods which enable the characterization of intermediates in reaction cycles and hence may provide experimental insight into mechanisms. Our primary efforts focus on X-ray absorption and X-ray emission spectroscopic studies, which will be carried out at the Cornell High Energy Synchrotron Source (CHESS), the Stanford Synchrotron Radiation Laboratory (SSRL) and other synchrotron facilities. These data will be complemented by more traditional spectroscopy (UV-Vis, EPR and vibrational data), as well as modern electronic structure calculations. Our research program provides students with training in advanced spectroscopic methods, data analysis, theoretical calculations and basic synthesis, as well as the opportunity to collaborate with experts in biochemistry, synthetic chemistry and theory.

Selected Publications:

"Fe L- and K-edge XAS of Ferric Corrole: Bonding and Reactivity Relative to Low-Spin Ferric Porphyrin” R. K. Hocking, S. DeBeer George, Z. Gross, F. Ann Walker, K. O. Hodgson, B. Hedman, E. I. Solomon, Inorg. Chem, 2009, 48, 1678-1688.

“Electronic Structure and Spectroscopy of Super-oxidized Iron Centers in Model Systems: Theoretical and Experimental Trends” J. F. Berry, S. DeBeer George, F. Neese, Phys. Chem. Chem. Phys., 2008, 10, 4361-4374.

“Prediction of Iron K-edge Absorption Spectra using Time-Dependent Density Functional Theory” S. DeBeer George, T. Petrenko, F. Neese, J. Phys. Chem. A, 2008, 112, 12936-12943.

“Characterization of a Genuine Iron(V)Nitrido Species by Nuclear Resonant Vibrational Spectroscopy Coupled to Density Functional Calculations” T. Petrenko, S. DeBeer George, N. Aliaga-Alcade, E. Bill, B. Mienert, W. Sturhahn, Y. Xiao, K. Wieghardt, F. Neese, J. Am. Chem. Soc., 2007, 129, 11053-11060.

“Polarized X-ray Absorption Spectroscopy of Single-crystal Mn(V) Complexes Relevant to the Oxygen Evolving Complex of Photosystem II” J. Yano, J. Robblee, Y. Pushkar, M. A. Marcus, K. Sauer, J. Bendix, T. J. Collins, E. I. Solomon, S. DeBeer George, and V. Yachandra, J. Am. Chem. Soc. , 2007, 129, 12989-13000.