NMR line shapes of tunneling methyl groups in enclathrated molecules
Journal Article
·
· J. Chem. Phys.; (United States)
/sup 1/H NMR line shapes, obtained at low temperatures (T<5 K), are reported for CH/sub 3/Br, CH/sub 3/CD/sub 2/Cl, and CH/sub 3/CD/sub 2/Br molecules enclathrated in the heavy water clathrate hydrates, and for CH/sub 3/CD/sub 2/I and CH/sub 3/CCl/sub 3/ molecules enclathrated together with D/sub 2/S, in the heavy water double clathrate hydrates. Line shapes for CH/sub 3/Br and CH/sub 3/CCl/sub 3/ are characteristic of very fast and slow tunneling, respectively. Those obtained for the ethyl halides indicated intermediate tunneling rates. To account for the latter line shapes it is necessary to include a distribution in tunneling frequencies in the Apaydin and Clough line shape calculation. Satisfactory simulated spectra are given by a log-normal distribution. The methyl group rotational barrier heights derived from the tunneling frequencies for a threefold sinusoidal barrier can be correlated with the guest molecule dimensions relative to the size of the clathrate hydrate cage.
- Research Organization:
- Division of Chemistry, National Research Council of Canada, Ottawa, Ontario, Canada K1A OR9
- OSTI ID:
- 5211385
- Journal Information:
- J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 68:4; ISSN JCPSA
- Country of Publication:
- United States
- Language:
- English
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Journal Article
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Sat Jun 07 00:00:00 EDT 2014
· Journal of Chemical Physics
·
OSTI ID:22304270
Nuclear magnetic resonance studies of guest species in clathrate hydrates: Line-shape anisotropies, chemical shifts, and the determination of cage occupancy ratios and hydration numbers
Journal Article
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Wed Jan 10 23:00:00 EST 1990
· Journal of Physical Chemistry; (USA)
·
OSTI ID:6711720
Spectroscopic determination of gas-water interactions in clathrate hydrates
Thesis/Dissertation
·
Mon Dec 31 23:00:00 EST 1984
·
OSTI ID:5585284
Related Subjects
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400202* -- Isotope Effects
Isotope Exchange
& Isotope Separation
BROMINATED ALIPHATIC HYDROCARBONS
CHLORINATED ALIPHATIC HYDROCARBONS
CLATHRATES
DEUTERIUM
DEUTERIUM COMPOUNDS
FLUORINATED ALIPHATIC HYDROCARBONS
HALOGENATED ALIPHATIC HYDROCARBONS
HEAVY WATER
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
IODINATED ALIPHATIC HYDROCARBONS
ISOTOPE EFFECTS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ODD-ODD NUCLEI
ORGANIC BROMINE COMPOUNDS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
OXYGEN COMPOUNDS
RESONANCE
STABLE ISOTOPES
WATER
400202* -- Isotope Effects
Isotope Exchange
& Isotope Separation
BROMINATED ALIPHATIC HYDROCARBONS
CHLORINATED ALIPHATIC HYDROCARBONS
CLATHRATES
DEUTERIUM
DEUTERIUM COMPOUNDS
FLUORINATED ALIPHATIC HYDROCARBONS
HALOGENATED ALIPHATIC HYDROCARBONS
HEAVY WATER
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
IODINATED ALIPHATIC HYDROCARBONS
ISOTOPE EFFECTS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ODD-ODD NUCLEI
ORGANIC BROMINE COMPOUNDS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
OXYGEN COMPOUNDS
RESONANCE
STABLE ISOTOPES
WATER