Téléchargement | - Voir le manuscrit accepté : Introducing new nuclei in solid state NMR of gas hydrates (PDF, 891 Kio)
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Auteur | Rechercher : Moudrakovski, Igor1; Rechercher : Ratcliffe, Chris1; Rechercher : Ripmeester, John1 |
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Affiliation | - Conseil national de recherches du Canada. Institut Steacie des sciences moléculaires du CNRC
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Format | Texte, Article |
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Conférence | 7th International Conference on Gas Hydrates (ICGH 2011), 17-21 July 2011, Edinburgh, Scotland, United Kingdom, July 17-21, 2011., Edinburgh, Scotland, United Kingdom |
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Sujet | Solid State NMR, Ultra-High Field, S-33, Kr-83, Xe-131, inclusion compounds, clathrates, gas hydrates, structure, cage occupancy |
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Résumé | Extensive developments in experimental techniques in recent years have opened new exciting opportunities for application of solid state nuclear magnetic resonance (SS NMR) in studies of gas hydrates and inclusion compounds in general. Perhaps the most important advance of the last ten years was the extension into very high magnetic fields beyond 20T. This progress is especially significant in studies concerned with low-γ, low natural abundance and quadrupolar nuclei. This work reports our recent exploration of hydrates with SS NMR of nuclei that were not so long ago completely out of reach for NMR, but can be very useful in hydrate research. Although 129Xe is a widely used NMR probe, the applications of low-γ isotope 131Xe were very scarce. Being a quadrupolar spin 3/2 nucleus, 131Xe provides an additional probe for sampling the electric field gradients in inclusion compounds. Another nucleus that has been seriously under-explored is 83Kr, with its very low-γ being the main obstacle. Here we report our attempts to utilize this nucleus in studies of gas hydrates and some other inclusion compounds such as β-quinol and tert-Bu-Calix[4]. In most cases the spectra are affected by the quadrupolar interactions, providing information on the symmetry of the environment of the guest molecules. The next nucleus to be discussed is 33S, which is notoriously difficult due to its low-γ, low natural abundance, and relatively large quadrupolar moment. Nevertheless, working at the field of 21.1T we succeeded in acquiring, in a reasonable time, natural abundance 33S SS NMR spectra of various H2 S and SO2 gas hydrates and inclusion compounds. The spectra are dominated by the quadrupolar interactions and reflect very well the symmetry of the cages encapsulating the guest molecules. The impact of the introduction of new NMR nuclei on hydrate research will be discussed. |
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Date de publication | 2011-07 |
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Dans | |
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Langue | anglais |
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Publications évaluées par des pairs | Oui |
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Numéro NPARC | 19727331 |
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Exporter la notice | Exporter en format RIS |
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Signaler une correction | Signaler une correction (s'ouvre dans un nouvel onglet) |
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Identificateur de l’enregistrement | 111cf589-1557-4cc0-96e8-2f3b712681e8 |
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Enregistrement créé | 2012-03-29 |
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Enregistrement modifié | 2020-04-21 |
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