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Accession number;02A0335449
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| Title;Molecular interactions and dynamics in clathrate hydrates of acetone and THF. |
| Author;
TAKEBAYASHI YOSHIHIRO
(Sangyogijutsusogoken)
YODA SATOSHI
(Sangyogijutsusogoken)
SUGETA TSUTOMU
(Sangyogijutsusogoken)
OTAKE KATSUTO
(Sangyogijutsusogoken)
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Journal Title;Program and Abstracts of Papers. High Pressure Conference of Japan
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Journal Code:L1222A
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ISSN:0917-6373
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VOL.42nd;NO.;PAGE.30(2001)
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| Figure&Table&Reference;FIG.2, REF.4 |
| Pub. Country;Japan |
| Language;Japanese |
| Abstract;Hydrogen bond interactions and rotational dynamics in acetone and THF hydrates have been studied by NMR measurements. The carbonyl carbon-13 chemical shift of acetone was measured as a function of temperature in the clathrate hydrate and the supercooled aqueous solution. The jump of the chemical shift upon the hydrate transition indicates the disruption of the acetone-water hydrogen bond due to the cage formation. After the hydrate formation, however, the acetone-water hydrogen bond still persists and is reduced with decreasing temperature. Such a decrease in the chemical shift was observed also in the supercooled aqueous solution. This similarity reveals the presence of the precursory structure for the clathrate cage even in the aqueous solution. The rotational dynamics of the guest molecule and the host water was studied by measuring the deuteron spin-lattice relaxation times T1. With decreasing temperature, the T1 value of the guest molecule decreased monotonously in the aqueous solution, but showed a discontinuous increase upon the hydrate transition. The increasing jump in the T1 value suggests that the guest molecule in the hydrate cage reorients faster than that in the aqueous solution. This is consistent with the significant reduction in the guest-host hydrogen bond interaction at the cage formation. (author abst.) |
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