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Chemical Bonding of Lead in Glasses through Isotropic vs Anisotropic Correlation: PASS Shifted Echo

✍ Scribed by Franck Fayon; Catherine Bessada; André Douy; Dominique Massiot

Publisher: Elsevier Science
Year: 1999
Tongue: English
Weight: 108 KB
Volume: 137
Category: Article
ISSN: 1090-7807
DOI: 10.1006/jmre.1998.1641

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✦ Synopsis

When observing spin I ‫؍‬ 1 2 nuclei with important chemical shift anisotropy in disordered materials, the distribution of isotropic shift can become so large that no accessible spinning rate is able to provide a resolved spectrum. This is the case of 207 Pb in glasses where static and high-speed MAS spectra are nearly identical. It is still possible in such a case to rebuild a spinning sideband free spectrum using a shifted echo modified PASS sequence. This makes it possible to discuss isotropic and anisotropic chemical shifts of lead in phosphate glasses, to characterize its structural role and its chemical bonding state.

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