Structure transition and tuning pattern in the double (Tetramethylammonium hydroxide plus gaseous guests) clathrate hydrates

Cited 19 time in webofscience Cited 0 time in scopus
  • Hit : 748
  • Download : 1
In this study, we present an extraordinary structural transition accompanying the occurrence of more than two coexisting clathrate hydrate phases in the double (CH4 + tetramethylammonium hydroxide (Me4NOH)) and (H-2 + Me4NOH) ionic clathrate hydrates using solid-state NMR spectroscopy (high-powered decoupling and CP/MAS) and powder X-ray diffraction. It was confirmed that structure-I (sI) and structure-II (sII) hydrates coexist as the water concentration increases. In the Me4NOH-depleted region, the unique tuning phenomenon was first observed at a chemical shift of -8.4 ppm where relatively small gaseous CH4 molecules partly occupy the sII large cages (sII-L), pulling out large cationic Me4N+ that is considered to be strongly bound with the surrounding host lattices. Moreover, we note that, while pure Me4NOH center dot 16H(2)O clathrate hydrates melted at 249 K under atmospheric pressure conditions, the double (CH4 + Me4NOH) clathrate hydrate maintained a solid state up to approximately 283 K under 120 bar of CH4 with a conductivity of 0.065 S cm(-1), suggesting its potential use as a solid electrolyte. The present results indicate that ionic contributions must be taken into account for ionic clathrate hydrate systems because of their distinctive guest dynamic behavior and structural patterns. In particular, microscopic analyses of ionic clathrate hydrates for identifying physicochemical characteristics are expected to provide new insights into inclusion chemistry.
Publisher
AMER CHEMICAL SOC
Issue Date
2007-08
Language
English
Article Type
Article
Keywords

(CH3)4NOH.5H2O; CONDUCTIVITY; PENTAHYDRATE

Citation

JOURNAL OF PHYSICAL CHEMISTRY B, v.111, no.34, pp.10224 - 10230

ISSN
1520-6106
DOI
10.1021/jp073910c
URI
http://hdl.handle.net/10203/3733
Appears in Collection
CBE-Journal Papers(저널논문)
Files in This Item
This item is cited by other documents in WoS
⊙ Detail Information in WoSⓡ Click to see webofscience_button
⊙ Cited 19 items in WoS Click to see citing articles in records_button

qr_code

  • mendeley

    citeulike


rss_1.0 rss_2.0 atom_1.0