Ring-substituted benzohydroxamic acids : 1H, 13C and 15N NMR spectra and NH-OH proton exchange
Copyright 2005 John Wiley & Sons, Ltd
| Publié dans: | Magnetic resonance in chemistry : MRC. - 1985. - 43(2005), 7 vom: 01. Juli, Seite 535-42 |
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| Auteur principal: | |
| Autres auteurs: | , , , , , |
| Format: | Article |
| Langue: | English |
| Publié: |
2005
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| Accès à la collection: | Magnetic resonance in chemistry : MRC |
| Sujets: | Comparative Study Evaluation Study Journal Article Research Support, Non-U.S. Gov't Carbon Isotopes Hydroxamic Acids Nitrogen Isotopes Protons Hydroxyl Radical 3352-57-6 plus... |
| Résumé: | Copyright 2005 John Wiley & Sons, Ltd NMR spectra (1H, 13C, 15N) of para- and meta-substituted benzohydroxamic acids were studied in dry dimethyl sulfoxide solutions. The 13C chemical shifts were very close to those found by cross-polarization magic angle spinning in solids, the hydroxamic (not hydroximic) structure of which is unambiguous. The hydroxamic structure of these acids in DMSO solutions was proved independently by their 15N chemical shifts. The 15N and 1H chemical shifts of the NH-OH fragment showed excellent mutual dependences and dependences on the nature of the ring substituent. According to these dependences and ab initio energy calculations, all the acids assume the same Z conformation. Proton exchange between hydroxamic OH and NH groups in DMSO proceeded by both intra- and intermolecular exchange and the rates did not exhibit any simple relationship to the substituent constants |
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| Description: | Date Completed 23.08.2005 Date Revised 10.12.2019 published: Print Citation Status MEDLINE |
| ISSN: | 0749-1581 |