Xenon is an inert gas whose large polarizability makes it very sensitive to electronic perturbation which is directly transmitted to the nucleus and therefore markedly affects the chemical shift. This overview, which is not exhaustive, presents some characteristic examples of the use of 129 Xe NMR t
Line shape analysis of 129Xe NMR spectra of xenon in zeolites
β Scribed by F. Rittner; A. Seidel; B. Boddenberg
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 276 KB
- Volume
- 243
- Category
- Article
- ISSN
- 0009-2614
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β¦ Synopsis
129Xe NMR spectra of xenon in zinc-exchanged zeolites have been calculated assuming a macroscopic inhomogeneity resulting from a distribution of adsorption site concentrations. The experimentally observed characteristics of the lines such as line widths and shapes are qualitatively reproduced, as well as their dependence on xenon pressure.
π SIMILAR VOLUMES
The adsorption isotherms and lz9Xe NMR chemical shifts of xenon in the voids of zeolite Y with O%, 53%, 75%, and 95% exchange of copper (II) for sodium ions were determined. With increasing copper content the shifts go uptield. The local chemical shifts of xenon at a crystallographic SII site with a
experiments we have determined values of the mean free path 1 of xenon adsorbed on various zeolites. We deduce from them the dependence of the chemical shift S on 1. It is now possible to determine the dimensions of any cavity in which xenon can be adsorbed.
Ion exchange in a mixture of RbNaX and NaY zeolites after different treatments was studied by lz9Xe-NMR of adsorbed xenon. The presence of water greatly favours the ion-exchange process. But this latter can also occur under water-free conditions upon heating. The exchange rate (on the NMR time scal