Orientation and motion of tetrahydrofuran in graphite intercalation compounds. Proton NMR studies of Cs(THF){sub 1.3}C{sub 24} and K(THF){sub 2.5}C{sub 24}

Journal Article · Thu Jun 29 04:00:00 EDT 1995 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/j100026a020· OSTI ID:81311

Schmidt, C; Rosen, M E; Caplan, D F; Pines, A ^[1]; Quinton, M F ^[2]

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1. Lawrence Berkeley Lab., CA (United States)
2. Laboratoire de Physique Quantique, Paris (France)

The orientation and motion of tetrahydrofuran (THF) in the ternary graphite intercalation compounds Cs(THF){sub 1.3}C{sub 24} and K(THF){sub 2.5}C{sub 24} have been studied by proton NMR. Simulations of the NMR spectra indicate that the THF molecules in Cs(THF){sub 1.3}C{sub 24} have their mean planes oriented parallel to the layers of the host lattice, while the THF molecules in K(THF){sub 2.5}C{sub 24} have their mean planes oriented at an angle between 50{degree} and 75{degree} from the graphite layers. The proton NMR spectra of both compounds show evidence that the THF molecules rotate about the normal to the graphite layers and confirm X-ray diffraction studies showing a degree of orientational disorder in the samples, corresponding to a mosaic spread in the graphite layer orientation. Simulations indicate that the conformation of intercalated THF is different than gas or liquid phase THF, which has been found to have a ring puckering amplitude of 0.38-0.44 A and to undergo nearly free pseudorotation through a series of conformations. Best agreement between simulated and experimental NMR spectra of Cs(THF){sub 1.3}C{sub 24} was obtained with THF interconverting between two conformations of C{sub s} symmetry and a puckering amplitude of 0.30 A. 31 refs., 15 figs.

• Sponsoring Organization: USDOE
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 81311
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 26 Vol. 99; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
99 GENERAL AND MISCELLANEOUS
CLATHRATES
GRAPHITE
HAMILTONIANS
MOTION
NMR SPECTRA
ORGANIC COMPOUNDS
ORIENTATION
TEMPERATURE DEPENDENCE
TETRAHYDROFURAN
X-RAY DIFFRACTION