Abstract Details
| Mononuclear Non-Heme XAS: A New Ligand Framework for the Iron (IV)=O Unit | |
|---|---|
| Abstract ID | BIO-13 |
| Presenter | Samuel Wilson |
| Presentation Type | Poster |
| Full Author List | S. A. Wilson (1) , J. Yoon (3) , Y. Jang (3) , M. Seo (3) , K. Nehru (3) , B. Hedman (2) , K. O. Hodgson (1,2) , E. I. Solomon (1,2) , W. Nam (3) |
| Affiliations | (1) Stanford University, Department of Chemistry (2) Stanford Synchrotron Radiation Laboratory (SSRL), SLAC (3) Ewha Womans University, Department of Chemistry |
| Category | Bio/Life Sciences |
| Abstract | Mononuclear non-heme iron oxygenases catalyze a diverse array of important metabolic transformations that require the binding and activation of dioxygen. Using X-ray absorption spectroscopy (XAS), pre-edge, edge and EXAFS analysis, a new mononuclear non-heme iron (IV)=O model has been characterized which utilizes the BQEN (BQEN = N,N’-dimethyl-N,N’- bis(8-quinolyl)ethane-1,2-diamine) ligand as its structural framework. Reaction of Fe(II)(BQEN)(CF3SO3)2 with CH3CO3H in CH3CN at 0ºC produces an EPR silent S=1 intermediate with a λmax at 740 nm. A short Fe=O bond exhibiting a distance of 1.67 Å has been spectroscopically observed via EXAFS as well as the characteristic pre-edge intensity increase and edge shift identify an Fe(IV)=O intermediate. [Fe(IV)=O(BQEN)]2+ additionally shows a high degree of reactivity in the oxidation of alkanes and alcohols, performing oxidation via a hydrogen-atom (H-atom) abstraction mechanism analogous to those in enzyme systems. |
| Footnotes | |
| Funding Acknowledgement | The research at EWU was supported by KOSEF/MOST through the CRI Program, Korea, and that at Stanford University by NIH grants RR-01209 (K.O.H.) and GM 40392 (E.I.S.). SSRL operations is funded by the U.S. DOE BES, and the SSRL SMB program by NIH NCRR BTP and DOE BER. The project described was supported by Grant Number 5 P41 RR001209 from the National Center for Research Resources (NCRR), a component of the National Institutes of Health (NIH) and its contents are solely the responsibility of the authors and do not necessarily represent the official view of NCRR or NIH. |