Characterization of Reactive Sites in Supported Catalysts by 51V/15N Rotational Echo Double Resonance NMR Spectroscopy: Formation of Phenylimido Groups at Surface-Bound Oxovanadium Sites
| Autor: | Thomas E. Gedris, Carole Brown, Riqiang Fu, Albert E. Stiegman, Randall Achey |
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| Rok vydání: | 2005 |
| Předmět: |
Magnetic Resonance Spectroscopy
Vanadium Compounds Nitrogen Isotopes Surface Properties Chemistry Pulse sequence General Chemistry Nuclear magnetic resonance spectroscopy Imides Resonance (chemistry) Biochemistry Catalysis chemistry.chemical_compound symbols.namesake Crystallography Colloid and Surface Chemistry Aniline Covalent bond symbols Spectroscopy Raman spectroscopy Nuclear chemistry |
| Zdroj: | Journal of the American Chemical Society. 127:11590-11591 |
| ISSN: | 1520-5126 0002-7863 |
| Popis: | Silica-supported oxovanadium groups were reacted in a gas-solid reaction with aniline at 175 degrees C. The reaction was clean as monitored in situ by UV-vis spectroscopy and resulted in the elimination of water as the principal product of the reaction and the disappearance of the terminal V=O stretch in the Raman spectrum. 15N MAS solid-state NMR spectroscopy showed only a single nitrogen-containing species on the surface. Proton-dephased 15N NMR showed only weak attenuation of its intensity, indicating that there are no protons directly bonded to the nitrogen. The formation of a vanadium-imido covalent bond was characterized by 51V/15N rotational echo double resonance NMR spectroscopy where the quadrupolar 51V nucleus was monitored and the spin-1/2 15N nucleus was dephased. |
| Databáze: | OpenAIRE |
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