Nuclear Quadrupole Perturbations in 51V NMR Spectra of Oxovanadium(+V) Complexes

Abstract

Nuclear electric quadrupole coupling constants e2qQ/h have been obtained by evaluation of quadrupole perturbations in 51V NMR spectra of various vanadyl esters and esterchlorides of the general formula V0Cl3_n (0R)n (n = 0 3; R = Me, Prn, Pri, Bun and Bui). e2qQlh values have been calculated from (i) 2nd. order quadrupole splittings of the 51V NMR signals in pseudo-polycrastalline samples, (ii) Ist. order quadrupole splittings in nematic liquid crystals and (iii) line widths Δv1/2 of the 51V and 35C1 NMR signals in the liquid isotropic state and e2qQ/h(35CI) obtained by pure NQR measurements. The influences of the asymmetry parameter ƞ and the orientation of the crystallites in powder spectra are considered, and temperature and concen-tration effects upon Δv1/2 and 51V shielding (isotropic phases) and the ordering factor Sa (meso-phases) are discussed. © 1982, Walter de Gruyter. All rights reserved.