Calculation and In-Plane Vibrational Assignment of Substituted Phosphapyrimidines and Their Nitrogen-15 Labelled Analogs

Recently we studied NQR ³⁵Cl and NMR ³¹P spectra of a series of substituted phosphapyrimidines, PhP, (1,2,6-phosphadiazines) and reported some peculiarities of the phosphadiazine ring structure¹. Continuing the investigation of this class of compounds, we have obtained in this work infrared and Raman spectra of some PhP and have calculated in-plane normal vibrations. Normal coordinate calculations have been made in order to aid in the assignment of the PhP fundamental frequencies and to obtain values for force constants of the phosphadiazine cycle to transfer to other phosphacyclic compounds.