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17 O NMR Spectroscopy of α‐TeO 2 and Na 2 TeO 3
Author(s) -
Hart Robert T.,
Zwanziger Josef W.
Publication year - 2005
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2005.00429.x
Subject(s) - chemical shift , spectroscopy , chemistry , oxide , nuclear magnetic resonance spectroscopy , nuclear magnetic resonance , paramagnetism , analytical chemistry (journal) , stereochemistry , condensed matter physics , physics , organic chemistry , chromatography , quantum mechanics
The synthesis of 17 O‐enriched α‐tellurite (α‐TeO 2 ) is described. TeO 2 is obtained stochiometrically by the reaction of tellurium isopropoxide with 17 O‐enriched H 2 O. The reaction is mild and simple and opens the field of tellurite‐based ceramics to 17 O nuclear magnetic resonance spectroscopy. We also report the first 17 O nuclear magnetic resonance spectra of α‐TeO 2 and Na 2 TeO 3 . Their isotropic chemical shifts, δ iso , are 180 ppm and 158 ppm, respectively, and their quadrupolar coupling parameters are C Q =7.48 MHz and η=0.43 for α‐TeO 2 , and C Q =6.63 MHz and η=0.33. By using extended Hückel tight binding calculations, we interpret the chemical shifts of tetravalent inorganic oxide network formers (SiO 2 , GeO 2 , and TeO 2 ) in terms of the local paramagnetic shielding effect. We also show that this is the predominant effect in determining the chemical shifts of non‐bridging oxide sites in this type of network.