Electron Spin Echo Envelope Modulation Spectroscopy Reveals and Distinguishes Equatorial and Axial Nitrogen Ligands Bound to VO2+
| Autor: | Gerard J. Colpas, Brent J. Hamstra, Wayne D. Frasch, Vincent L. Pecoraro, Russell LoBrutto |
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| Rok vydání: | 1998 |
| Předmět: |
Iminodiacetic acid
Ligand Nitrilotriacetic acid Analytical chemistry General Chemistry Biochemistry Catalysis Spectral line law.invention chemistry.chemical_compound Crystallography Colloid and Surface Chemistry chemistry law Moiety Amine gas treating Electron paramagnetic resonance Envelope (waves) |
| Zdroj: | Journal of the American Chemical Society. 120:4410-4416 |
| ISSN: | 1520-5126 0002-7863 |
| DOI: | 10.1021/ja973517s |
| Popis: | ESEEM (electron spin echo envelope modulation) spectra of a series of vanadyl complexes have for the first time revealed the spectral features that arise from amine nitrogen donors trans to the vanadyl oxo moiety. The complexes [VO(H2O)ada] (1) and [VO(H2O)Hheida] (2) (H2ada, N-(2-acetamido)iminodiacetic acid; H3heida, N-(2-hydroxyethyl)iminodiacetic acid) have recently been synthesized and crystallographically characterized (Hamstra, B. J.; Houseman, A. L. P.; Colpas, G. J.; Kampf, J. W.; LoBrutto, R.; Frasch, W. D.; Pecoraro, V. L. Inorg. Chem. 1997, 36, 4866−4874). In each structure, the ligand is disposed so that the tertiary nitrogen is bound trans to the vanadyl oxo. In solution, the structural integrity of these compounds is maintained as observed by UV/vis and EPR spectroscopies. ESEEM spectra of 1, 2, and [VO(H2O)nta]- (3) (H3nta, nitrilotriacetic acid) reveal that the superhyperfine coupling constants for axial amines are ≅1.3 MHz as opposed to the ≅5.0 MHz superhyperfine couplings typically obs... |
| Databáze: | OpenAIRE |
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