Jelena Šepa

13C chemical shielding anisotropy in the solid phases of CH313CN

Abstract The principal elements of the axially symmetric nitrile 13 C chemical shift tensor, and the CN bond distance of solid CH 3 CN have been determined from both static and sample spinning NMR experiments at 78 and 140 K. The spectra show no significant differences between the α and β forms of the solid though a large temperature coefficient is observed for both the isotropic chemical shift, σ , and the 14 N nuclear electric quadrupole interactions as seen through the carbon-nitrogen dibole interaction.

The 13C chemical shielding, 14N quadropole and the dipolar tensors of the nitrile group in the hydrogen-bonded acetonitrile-H-ZSM-5 adsorption complex

Abstract The principal components and orientation of the principal axes of the 13C chemical shielding. 14N electric field gradient and CN dipolar tensors of the nitrile group of the 1 : 1 stoichiometric acetonitrile-H-ZSM-5 adsorption complex have been determined from 13C NMR static and variable-angle slow spinning spectra. These results are compared with experimental NMR parameters of solid acetonitrile and ab initio calculations of a small cluster. The most significant differences are in the relative orientations of the principal axes of the three tensors. In the solid and molecule-cluster complex, these are near coincident, but not for the zeolite complex.