Student Hosted Colloquia: Professor Jonas Peters, Caltech, Sapp Center Lecture Hall, 4:30pm (Host: Wilson Ho)
About the Seminar:
"Synthetic single-site iron nitrogenases"
Nitrogen reduction to NH3 is a requisite transformation for life. While it is widely appreciated that the Fe-rich cofactors of nitrogenase enzymes facilitate this transformation, how they do so remains poorly understood. A central element of debate has been the site(s) of dinitrogen coordination and reduction. The synthetic inorganic community placed an early emphasis on Mo because Mo was thought to be an essential element of nitrogenases, and because pioneering work by Chatt and his coworkers established that well-defined Mo model complexes could mediate the stoichiometric conversion of coordinated N2 to NH3. Catalytic N2-to-NH3 conversion was later demonstrated using a molecular Mo catalyst by Schrock.
It is known, however, that Fe is the only transition metal essential to all nitrogenases, and recent biochemical and spectroscopic data have implicated Fe as the likely site of N2 binding in FeMo-co. These observations motivate our search for functional Fe catalysts. In this lecture, I will discuss a tris(phosphine)borane supported Fe complex that catalyzes the reduction of N2 to NH3. This catalytically functional model system established for the first time that a single Fe site is capable of stabilizing the various NxHy ligands generated en route to NH3 formation. Recent efforts have targeted improving the efficiency of these synthetic iron nitrogenases via exploring alternative conditions and catalyst scaffolds, and using both experiment and theory to better understand the mechanisms by which these catalysts function.
About the Speaker:
Jonas Peters was born in 1971 in Chicago, Illinois. In 1993 he received his Bachelor of Science degree in chemistry at the University of Chicago, where he worked with Professor Gregory Hillhouse on synthetic methods in inorganic chemistry, specifically with regard to the stabilization of reactive species including HN=NH and HNO.
Jonas then spent a year as a Marshall Scholar at the University of Nottingham, UK, working with Professor James J. Turner, FRS. Jonas studied physical inorganic chemistry including photochemical generation and the detection of short-lived transients by rapid time-resolved methods.
In the fall of 1994, Jonas left Nottingham to begin his doctoral studies under the direction of Professor Christopher C. Cummins at the Massachusetts Institute of Technology. Jonas' research focused on the activation and functionalization of small molecules using low coordinate tris-amido molybdenum and titanium complexes, and included the synthesis of the first terminal carbide complex of a transition metal.
After receiving his Ph.D. in inorganic chemistry in 1998, Jonas was a Miller Fellow at the University of California, Berkeley, under the guidance of Professor T. Don Tilley. At Berkeley, Jonas concentrated on the synthesis and employment of novel phosphine, silane, and phosphino silane ligands relevant to late metal Si-C, Si-H, C-H, and C-C bond breaking and forming processes.
Jonas began as assistant professor in the Division of Chemistry and Chemical Engineering at Caltech in August of 1999, was promoted to associate professor in 2004, and to Professor of Chemistry in 2006. In July of 2007, he relocated to the MIT Department of Chemistry as the W. M. Keck Professor of Energy. Jonas returned to Caltech in January 2010 as Bren Professor of Chemistry is currently Director of the Resnick Sustainability Institute. His research program pushes the boundaries of our understanding of the structure, bonding, and catalytic activity of inorganic compounds, particularly ones of relevance to global C, N, and O cycles and energy applications.