CORRELATION OF P-31 CHEMICAL-SHIFT PARAMETERS TO MOLECULAR-STRUCTURESOF HEXACOORDINATE ORGANOPHOSPHORUS COMPOUNDS IN THE SOLID-STATE

P-31 principal elements of chemical shift tensors delta(ii) for a seri es of hexacoordinate organophosphorus compounds have been obtained fro m spinning sideband intensities employing the MASNMR program based on a graphical method of Berger and Herzfeld. It was found that anisotrop y parameters Delta delta and span Omega reflect the distortion of the molecular structure from the ideal octahedral geometry. The asymmetry parameter eta and skew kappa suggest that the phosphorus shielding dep ends not only on the local bonding, but also on the octahedral structu re as a whole. Comparison of isotropic chemical shifts in solution and in solids revealed that in both phases the molecular structures are n ot changed. Moreover, this work shows that for P-VI moieties with unkn own X-ray structure, crucial information regarding the geometry can be obtained from solid-state NMR data and a molecular modelling approach .