95Mo Magic Angle Spinning NMR at High Field: Improved Measurements and Structural Analysis of the Quadrupole Interaction in Monomolybdates and Isopolymolybdates Научная публикация
Журнал |
The Journal of Physical Chemistry B
ISSN: 1520-6106 , E-ISSN: 1520-5207 |
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Вых. Данные | Год: 2005, Том: 109, Номер: 29, Страницы: 14033-14042 Страниц : 10 DOI: 10.1021/jp0519621 | ||||||||
Ключевые слова | Catalysis; Correlation methods; Electron transitions; Fourier transform infrared spectroscopy; Nuclear magnetic resonance; Probability density function; Structural analysis; Synthesis (chemical) | ||||||||
Авторы |
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Организации |
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Реферат:
In this study, 95Mo quadrupole couplings in various molydbates were measured easily and accurately with magic angle spinning (MAS) NMR under a directing field of 19.6 T. The resonance frequency of 54 MHz was sufficiently high to remove acoustic ringing artifacts, and the spectra could be analyzed in the usual terms of chemical shift and quadrupolar line shapes. For monomolybdates and molybdite, the quadrupole coupling dominated the NMR response, and the quadrupole parameters could be measured with better accuracy than in previous lower field studies. Moreover, despite the low symmetry of the molybdenum coordination, the usefulness of such measurements to probe molybdenum environments was established by ab initio density functional theory (DFT) calculations of the electric field gradient from known structures. The experimental NMR data correlated perfectly with the refined structures. In isopolymolybdates, the resonances were shapeless and DFT calculations were impossible because of the large and low symmetry unit cells. Nevertheless, empirical but clear NMR signatures were obtained from the spinning sidebands analysis or the MQMAS spectra. This was possible for the first time thanks to the improved baseline and sensitivity at high fields. With the generalization of NMR spectrometers operating above 17 T, it was predicted that 95Mo MAS NMR could evolve as a routine characterization tool for ill-defined structures such as supported molybdates in catalysis.
Библиографическая ссылка:
d’Espinose de Lacaillerie J-B.
, Barberon F.
, Romanenko K.V.
, Lapina O.B.
, Le Pollès L.
, Gautier R.
, Gan Z.
95Mo Magic Angle Spinning NMR at High Field: Improved Measurements and Structural Analysis of the Quadrupole Interaction in Monomolybdates and Isopolymolybdates
The Journal of Physical Chemistry B. 2005. V.109. N29. P.14033-14042. DOI: 10.1021/jp0519621 WOS Scopus РИНЦ
95Mo Magic Angle Spinning NMR at High Field: Improved Measurements and Structural Analysis of the Quadrupole Interaction in Monomolybdates and Isopolymolybdates
The Journal of Physical Chemistry B. 2005. V.109. N29. P.14033-14042. DOI: 10.1021/jp0519621 WOS Scopus РИНЦ
Даты:
Поступила в редакцию: | 15 апр. 2005 г. |
Принята к публикации: | 27 мая 2005 г. |
Опубликована в печати: | 1 июл. 2005 г. |
Опубликована online: | 2 июл. 2005 г. |
Идентификаторы БД:
Web of science | WOS:000230698100028 |
Scopus | 2-s2.0-23844522814 |
РИНЦ | 13495409 |
Chemical Abstracts | 2005:582152 |
Chemical Abstracts (print) | 143:277400 |
OpenAlex | W2074483277 |