Nuclear magnetic resonance studies of xenon clusters in zeolite NaA

Jameson, Cynthia J. ; Jameson, A. Keith ; Gerald, Rex ; de Dios, Angel C.

College Park, Md. : American Institute of Physics (AIP)
Published 1992
ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
Chemistry and Pharmacology
Notes:
We have observed the equilibrium distribution of Xe atoms trapped in the alpha cages of zeolite NaA at 300 and at 360 K for low to high xenon loadings. The experimental distributions obtained by nuclear magnetic resonance (NMR) spectroscopy differ from two previously proposed statistical distributions. The experimental deviations from these statistical models can be explained by the attractive Xe–Xe interactions which favor clustering at low to medium loading, and the higher energies associated with the overcrowded cage disfavoring clusters of eight Xe atoms at high loadings. The temperature dependence of the 129Xe NMR chemical shift of each cluster has been measured in the range 188–421 K, except that for Xe8, which was determined only up to 300 K. The observed shifts and their temperature dependence are interpreted by using the results of ab initio calculations of the intermolecular shielding function in the 39Ar system as a model for the 129Xe system.
Type of Medium:
Electronic Resource
URL: