A theoretical study on correlation between the structures and 31P NMR chemical shifts of dicoordinated phosphenium cations

MNDO calculations are performed for studying correlation between the electronic and geometrical structures and P-31 NMR chemical shifts of dicoordinated phosphenium cations. A simple relationship is introduced to elucidate the 31P NMR chemical shifts of the cations from the calculated net atomic charges of the related atoms, Wiberg bond orders between the phosphorus atom and the atoms attached to it, and the bond angle at the phosphorus. The agreement of the calculated numerical results with the experimental data shows that the relationship obtained in-this paper is satisfactory for the prediction of the P-31 NMR chemical shifts of the dicoordinated phosphenium cations.