|
> ABRC Home > People List > Robert K. Szilagyi
FACULTY >Robert K. Szilagyi
Research Interests
The molecular understanding of how the electronic and geometric structures of iron-sulfur clusters, nanoparticles, and mineral surfaces contribute to their reactivity in small molecule activation and conversion to more complex building blocks of life is key to assess their catalytic importance. The Szilagyi Group utilizes both experimental spectroscopic and theoretical computational approaches to gain insights into structure/function relationship of iron-sulfur systems. Using tunable synchrotron radiation, X-ray absorption spectroscopic technique has the potential to give direct experimental information about both electronic and geometric structures, which can be used to calibrated density functional theory and ab initio electronic structure calculations to simulate both the experimentally observable and non-observable intermediates and transition states. These together provide potential energy descriptions of activation of H2, N2, CO2, CN-, CH4, to name few inert molecules that have been implicated as building blocks for chemical origin of life.
We are compiling an extensive multi-edge X-ray absorption spectroscopic library for iron-sulfur minerals (pyrite, chalcopyrite, troilite, marcasite, pyrrhotite), nanoparticles synthesized in various protein cages and viral capsids under systematically varied temperature and pH conditions, and clusters that are biomimetic models of catalytic active site clusters in FeFe-hydrogenases, Mo-nitrogenase, and SAM-radical enzymes. The spectral assignments, interpretation, and the quantitative analysis are aided by calibrated density functional calculations.
Furthermore, we are developing virtual chemical models that can reproduce both the structural features of mineral surface defects sites as well as their reactivity. These models will allows us to run simulations of various scenarios for small molecule activations that in our hypothesis contributed to the chemical origin of life. The rational and guidance for the computer simulations are provided by small molecule activation events from biology, such as the chemical function and mechanism of nitrogenases and hydrogenases. In a collaborative effort we work on understanding the molecular details of how inert molecules such as dinitrogen or dihydrogen can be activated at ambient conditions. Learning from these bioinorganic and metalloenzymatic examples and employing computer simulations we aim to provide some of the key puzzles to the chemical origin of life here on Earth.
Selected Publications
A.S. Pandey, T.V. Harris, L.J. Giles, J.W. Peters, and R.K. Szilagyi, Dithiomethylether as a Ligand in the Hydrogenase H-Cluster, JACS, 2008, 130(13), 4533-4540
D.E. Schwab, C. Tard, E. Brecht, J.W. Peters, C.J. Pickett, and R.K. Szilagyi. Delocalized Electronic Structure of Hydrogenase H-cluster Probed by X-ray Absorption Spectroscopy and Density Functional Theory. 3696-3698 Chem. Comm. (2006)
J.W. Peters and R.K. Szilagyi, Exploring new frontiers of nitrogenase structure and mechanism, Curr. Opin. Chem. Biol., 2006, 10(2), 101-108
J.W. Peters, R.K. Szilagyi, A. Naumov, T. Douglas, A radical solution for the biosynthesis of the H-cluster of hydrogenase, FEBS Lett., 2006, 580(2), 363-367
R.K. Szilagyi, and M. Winslow, On the accuracy of density functional theory for iron - sulfur clusters, J. Comp. Chem., 2006, 27(12), 1385-1397
E.I. Solomon, B. Hedman, K.O. Hodgson, A. Dey, R.K. Szilagyi, Ligand K-edge X-ray absorption spectroscopy: covalency of ligand-metal bonds, Coord. Chem. Rev., 2005, 249(1-2), 97-129
Lab Personnel
Dr. Alexios Grigoropoulos
Post-Doctoral Associate
agrigoropoulos@chemistry.montana.edu
David Gardenghi
Graduate Student
dgardenghi@gmail.com
Logan Giles
Graduate Student
logangiles@gmail.com
Travis V. Harris
Graduate Student
snakedog@gmail.com
Ethan Edwards
Undergraduate Student
ethan.edwards@myportal.montana.edu
Collaborators
Dr. Britt Hedman (X-ray Absorption Spectroscopy)
Stanford Synchrotron Radiation Lightsource
Stanford University
Dr. Lance Seefelt (Nitrogenase Biochemistry)
Department of Chemistry and Biochemistry
Utah State University
Dr. Chris Pickett (Synthetic Inorganic Chemistry and Electrochemistry)
Chemical Sciences and Pharmacy
University of East Anglia
Dr. Mike Heinekey (Synthetic Inorganic Chemistry and NMR Spectroscopy)
Department of Chemistry
University of Washington
Dr. Mike Frisch (Software Development and Support)
Gaussian Inc, Wallingford, CT
MORE>
|
