N 72 NMR and structural features of H2V12031_y*nH20 / A. V. Dmitriev, T. A. Denisova, S. G. Arsenov, V. L. Volkov // Journal of Structural Chemistry. - 1992. - Vol. 33, № 3. - P392-396 : il. - Bibliogr. : p. 396 (8 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): КСЕРОГЕЛИ -- ПОЛИВАНАДИЕВАЯ КИСЛОТА -- ЯМР -- ПЛЕНКИ Аннотация: In H2VI2031-y.nH20 films with different degrees of hydration, parameters of hyperfine interaction on SlY nuclei have been determined. It has been established that the of axial symmetry plane of the tensor of magnetic interactions coincides with the plane of the film. For a completely dehydrated specimen, values have been found for the most probable direction (40 ~ from the plane of the film) and magnitude of the electric field gradient (EFG) on SiV nuclei (eq-Q/h = 0.2333 MHz). Analysis of the angular dependence of the width of the satellites has shown the presence of disorientation of the principal direction of the EFG with a width of distribution about 50 ~ in the plane of the film. In view of the absence of satellites and the presence of an angular dependence of the central transition of the 51V NMR spectra of the hydrated specimens, it can be stated that the interaction of the V-O layer with water molecules leads to an increase of disorientation in the plane of the film. The change in magnetic shifts is discussed, and it is concluded that there is a nonuniform change of population of the conduction band upon dehydration Полный текст |