S. Hayashi
Dec 5, 2003
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Influential Citations
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Citations
Journal
Microporous and Mesoporous Materials
Abstract
Abstract Molecular motions of acetonitrile- d 3 and n -hexane- d 14 adsorbed at loading levels of 1 molecule per unit cell in AlPO 4 -5 are studied by 2 H NMR. The spectra are recorded in the temperature range from 139 to 372 K. The spectra of acetonitrile- d 3 are successfully simulated assuming molecules with six-site jumps together with those undergoing isotropic motions in the central space of the channel. The activation energy and the inverse of the frequency factor for the jump are estimated as 20.5 ± 0.6 kJ/mol and (5 ± 3) × 10 −12 s, respectively. The spectra for n -hexane- d 14 consist of three Pake doublet patterns, whose effective QCC values decrease linearly with temperature. Rotation of the methyl group, rotation of the whole molecule around the molecular axis and fluctuation of the molecular axis take place simultaneously, the rates of which are fast enough.