Second-order quadrupolar-dipolar broadening in two-dimensional multiple-quantum MAS NMR

Citation
J. Mcmanus et al., Second-order quadrupolar-dipolar broadening in two-dimensional multiple-quantum MAS NMR, CHEM P LETT, 311(3-4), 1999, pp. 292-298
Citations number
19
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
CHEMICAL PHYSICS LETTERS
ISSN journal
00092614 → ACNP
Volume
311
Issue
3-4
Year of publication
1999
Pages
292 - 298
Database
ISI
SICI code
0009-2614(19990924)311:3-4<292:SQBITM>2.0.ZU;2-K
Abstract
Second-order perturbation theory predicts the existence of a 'cross term' b etween the quadrupolar and dipolar interactions of two spin I = 3/2 nuclei. This cross term manifests itself as a broadening in solid-state NMR spectr a of spin I = 3/2 nuclei which cannot be fully removed by magic angle spinn ing (MAS) and has on inverse dependence on the Larmor frequency, omega(0). In these attributes, the second-order quadrupolar-dipolar broadening does n ot differ from pure second-order quadrupolar broadening. However, we show h ere that the recently developed two-dimensional multiple-quantum (MQ) MAS N MR technique, designed originally to suppress second-order quadrupolar broa dening, allows the two broadening interactions to be separated and quantifi ed. (C) 1999 Elsevier Science B.V. All rights reserved.