31P MAS-NMR an Phosphoroxidsulfiden — experimentelle Bestimmung und quantenchemische Berechnung der Tensoren der chemischen Verschiebung

³¹P MAS-NMR of Phosphorus Oxide Sulfides — Experimental Determination and Quantumchemical Calculation of Chemical Shift Tensors By high resolution solid state ³¹P MAS NMR and analysis of spinning sidebands the principal values of the chemical shift tensors in the series P₄O₆S_n with n = 0–4 have been determined. The orientations of the corresponding principal axes within the molecules have been derived. All magnetic shielding tensors show axial symmetry within the limits of experimental error. Thus the orientation of the shielding tensor within the molecules can be deduced indirectly. This information is usually not accessible for polycrystalline samples. The principal values of the tensor of the trivalent phosphorus atoms in P₄O₆S seem to deviate considerably from those of the other compounds with respect to anisotropy and axiality. The reason is a dynamic effect: the rotation of the molecule about the PS bond. All experimental results are confirmed by ab-initio calculations using the IGLO method.