Abnormal Thermal Expansion of Clathrate Hydrates Induced by Asymmetric Guest Molecules

2011 ◽  
Vol 7 (1) ◽  
pp. 122-126 ◽  
Author(s):  
Minjun Cha ◽  
Yeobum Youn ◽  
Minchul Kwon ◽  
Kyuchul Shin ◽  
Seongsu Lee ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Clathrate Hydrates ◽  
Guest Molecules

scholarly journals Characterization of free radicals in clathrate hydrates of pyrrole, thiophene, and isoxazole by muon spin spectroscopy

2018 ◽  
Vol 96 (2) ◽  
pp. 217-225 ◽  
Author(s):  
Mina Mozafari ◽  
Lalangi Chandrasena ◽  
Iain McKenzie ◽  
Kerim Samedov ◽  
Paul W. Percival
Keyword(s):  
Free Radicals ◽  
Muon Spin ◽  
Carbon Dioxide Sequestration ◽  
Clathrate Hydrates ◽  
Pure Liquid ◽  
Guest Molecules ◽  
Hyperfine Constants ◽  
Potential Applications ◽  
Muon Spin Spectroscopy

Gas hydrates have long been of interest to the petrochemical industry, but there has been growing interest in potential applications for carbon dioxide sequestration and hydrogen storage. This has prompted many fundamental studies of structure and host–guest interactions, but there has been relatively little investigation of chemical reactions of the guest molecules. In previous work, we have shown that it is possible to use muon spin spectroscopy to characterize H atom like muonium and muoniated free radicals formed in clathrate hydrates. Muonium (Mu) forms in clathrate hydrates of cyclopentane and tetrahydrofuran, whereas furan and its dihydro derivatives form radicals. The current work extends studies to clathrates hydrates of other five-membered heterocycles: thiophene, pyrrole, and isoxazole. All form structure II hydrates. In addition to the clathrates, pure liquid samples of the heterocycles were studied to aid in the assignment of radical signals and for comparison with the enclathrated radicals. Similar to furan, two distinct radicals are formed when Mu reacts with thiophene and pyrrole. However, only one muoniated radical was detected from isoxazole. Muon, proton, and nitrogen hyperfine constants were determined and compared with values predicted by DFT calculations to aid the structure assignments. The results show that Mu adds preferentially to the carbon adjacent to the heteroatom in thiophene and pyrrole and to the carbon adjacent to oxygen in isoxazole. The same radicals are formed in clathrates, but the spectra have broader signals, suggesting slower tumbling. Furthermore, additional signals in the avoided level-crossing spectra indicate anisotropy consistent with restricted motion of the radicals in the clathrate cages.

scholarly journals Effect of temperature and large guest molecules on the C–H symmetric stretching vibrational frequencies of methane in structure H and I clathrate hydrates

RSC Advances ◽  
2020 ◽  
Vol 10 (30) ◽  
pp. 17473-17478
Author(s):  
Go Fuseya ◽  
Satoshi Takeya ◽  
Akihiro Hachikubo
Keyword(s):  
Temperature Effect ◽  
Vibrational Frequencies ◽  
Clathrate Hydrates ◽  
Effect Of Temperature ◽  
Guest Molecules

Temperature effect on C–H symmetric stretching frequencies of CH4 in water cages of sI and sH clathrate hydrates were clarified.

The crystal structure and thermal expansion of the CCl4 adduct of Dianin's compound

1990 ◽  
Vol 68 (8) ◽  
pp. 1352-1356 ◽  
Author(s):  
Walter Abriel ◽  
André Du Bois ◽  
Marek Zakrzewski ◽  
Mary Anne White
Keyword(s):  
Crystal Structure ◽  
Thermal Expansion ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Guest Molecules ◽  
X Ray ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients ◽  
Dianin's Compound

The crystal structure of the title compound has been determined by single crystal X-ray diffraction data collected at 293 K, and refined to a final Rw of 0.057. The crystals are rhombohedral, space group [Formula: see text], with a = 27.134(8) Å, c = 10.933(2) Å, and Z = 18. The mole ratio of Dianin's compound (4-p-hydroxyphenyl-2,2,4-trimethylchroman) to CCl4 is 6:1. The guest molecules are disordered. X-ray powder diffraction was carried out in the temperature range from 10 to 300 K. From this, the thermal expansion coefficients for the a- and c-axes and the volume have been determined. Keywords: thermal expansion, crystal structure, clathrate.

Polarization response of clathrate hydrates capsulated with guest molecules

2016 ◽  
Vol 144 (20) ◽  
pp. 204308 ◽  
Author(s):  
Qun Zeng ◽  
Jinshan Li ◽  
Hui Huang ◽  
Xinqin Wang ◽  
Mingli Yang
Keyword(s):  
Clathrate Hydrates ◽  
Guest Molecules ◽  
Polarization Response

Nitrogen and oxygen guest molecules in clathrate hydrates: different sites revealed by Raman spectroscopy

1997 ◽  
Vol 28 (9) ◽  
pp. 711-715 ◽  
Author(s):  
B. Champagnon ◽  
G. Panczer ◽  
B. Chazallon ◽  
L. Arnaud ◽  
P. Duval ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Clathrate Hydrates ◽  
Guest Molecules

Role of Guest Molecules in the Mechanical Properties of Clathrate Hydrates

2018 ◽  
Vol 18 (11) ◽  
pp. 6729-6741 ◽  
Author(s):  
Qiao Shi ◽  
Pinqiang Cao ◽  
Zhengde Han ◽  
Fulong Ning ◽  
Hao Gong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Clathrate Hydrates ◽  
Guest Molecules
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