MAGNITUDES AND RELATIVE ORIENTATION OF V-51 QUADRUPOLE COUPLING AND ANISOTROPIC SHIELDING TENSORS IN METAVANADATES AND KV3O8 FROM V-51 MAS NMR-SPECTRA - NA-23 QUADRUPOLE COUPLING PARAMETERS FOR ALPHA-NAVO3 ANDBETA-NAVO3

V-51 MAS NMR spectra, exhibiting the complete manifold of spinning sid ebands (ssb's) from all seven V-51 (I = 7/2) single-quantum transition s, have been obtained for a series of metavanadates (MVO3, M = Li, Na, K, NH4, Tl) and for KV3O8 employing spectral windows up to 2 MHz. The se MAS NMR spectra are influenced by interactions from both the V-51 q uadrupole coupling and chemical shielding anisotropy. Analysis of the spectra has been performed in terms of the two interactions employing a newly developed method requiring simulations and iterative fitting o f the calculated to the experimental intensities of the spinning sideb ands. Accurate values for all eight parameters describing the magnitud e and relative orientation of the quadrupole coupling and anisotropic shielding tensors are obtained. The applicability and high performance of the method are illustrated by comparison of simulated and experime ntal MAS spectra, but also when V-51 parameters are compared to litera ture data determined for a few of the vanadates from static NMR and nu clear quadrupole resonance. Correlations between V-51 parameters and s tructural characteristics for the metavanadates are discussed. Further more, the two polymorphs alpha- and beta-NaVO3 along with a commercial sample of sodium metavanadate (consisting of a mixture of these polym orphs) are characterized by Na-23 MAS NMR and the Na-23 quadrupole cou pling parameters and isotropic chemical shifts determined from these s pectra.