| X-Ray Absorption Spectroscopy of Non-Heme {FeNO}6 and {FeNO}7 Compounds | |
| Abstract ID | 27 |
| Presenter | James Yan |
| Presentation Type | Poster |
| Full Author List | Chung-Hung Hsieh, Margarita Gonzales, Marcetta Darensbourg, Pradip Mascharak, Britt Hedman, Keith Hodgson, Edward Solomon |
| Affiliations | Stanford University |
| Category | |
| Abstract | Nitrosyl is a classic “non-innocent” ligand, and elucidating the electronic structure of Fe-NO compounds can be an interesting problem. Fe-NO centers are present across a range of biological systems, such as nitric oxide reductase and nitrile hydratase. Additionally, Fe-NO is a spectroscopically stable analog to Fe-O2 intermediates in heme and non-heme iron enzymes. In this project, L-edge absorption spectroscopy and DFT calculations are used to study the electronic structure of a six-coordinate {FeNO}6 S=0 compound, [Fe(PaPy3)NO]2 in comparison with the corresponding {FeNO}7 S=1/2 compound, [Fe(PaPy3)NO]+, and the S=0 compound [Fe(PaPy3)CO]+ (Fig. 1). The {FeNO}6 compound has been shown to be photolabile, while the {FeNO}7 version is not. L-Edge spectroscopy has been used to evaluate the covalency in [Fe(PaPy3)CO]+, and will be extended to studying the {FeNO}6 compound.
L-edge spectroscopy and DFT calculations are also being used to investigate the relationship between coordination number and electronic structure in {FeNO}7 S=1/2 compounds. Aside from the six-coordinate {FeNO}7 compound mentioned above, spectra have also been obtained on the five-coordinate {FeNO}7 compounds: Fe(bpb)NO, Fe(bme-daco)NO, and Fe(bme-dach)NO. These projects represent works in progress. Further quantitative analysis on the L-edge spectra and DFT calculations are required. |
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| Funding Acknowledgement | |