S K-Edge X-Ray Absorption Spectroscopy and Density Functional Theory Studies of High and Low Spin {FeNO}7 Thiolate Complexes: Exchange Stabilization of Electron Delocalization in {FeNO}7 and {FeO2}8
| Autor: | Gloria Villar-Acevedo, Britt Hedman, Lei V. Liu, Ning Sun, Julie A. Kovacs, Edward I. Solomon, Marcetta Y. Darensbourg, Keith O. Hodgson, Abhishek Dey |
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| Rok vydání: | 2010 |
| Předmět: |
Models
Molecular Ligand field theory X-ray absorption spectroscopy Absorption spectroscopy Spin states Chemistry Inorganic chemistry Electron Spin Resonance Spectroscopy Center (category theory) Electrons Electronic structure Article Inorganic Chemistry Crystallography X-Ray Absorption Spectroscopy X-Ray Diffraction K-edge Indicators and Reagents Density functional theory Ferrous Compounds Sulfhydryl Compounds Physical and Theoretical Chemistry Sulfur |
| Zdroj: | Inorganic Chemistry. 50:427-436 |
| ISSN: | 1520-510X 0020-1669 |
| DOI: | 10.1021/ic1006378 |
| Popis: | S K-edge X-ray absorption spectroscopy (XAS) is a direct experimental probe of metal ion electronic structure as the pre-edge energy reflects its oxidation state, and the energy splitting pattern of the pre-edge transitions reflects its spin state. The combination of sulfur K-edge XAS and density functional theory (DFT) calculations indicates that the electronic structures of {FeNO}(7) (S = 3/2) (S(Me2)N4(tren)Fe(NO), complex I) and {FeNO}(7) (S = 1/2) ((bme-daco)Fe(NO), complex II) are Fe(III)(S = 5/2)-NO(-)(S = 1) and Fe(III)(S = 3/2)-NO(-)(S = 1), respectively. When an axial ligand is computationally added to complex II, the electronic structure becomes Fe(II)(S = 0)-NO•(S = 1/2). These studies demonstrate how the ligand field of the Fe center defines its spin state and thus changes the electron exchange, an important factor in determining the electron distribution over {FeNO}(7) and {FeO2}(8) sites. |
| Databáze: | OpenAIRE |
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