Etude en spectrographie i.r. du vibrateur (Pv)NH dans quelques phosphoranes dérivés d'hydrazides

The absorption band due to the NH stretching vibration has been studied in spiro- or monocyclicphosphoranes derived from hydrazides and containing the PNHN system. The results suggest a large degree of delocalization of the nitrogen lone pair towards phosphorus. The acidity of the NH proton appears to be strongly dependent upon the electronegativities of the atoms of groups bound to phosphorus. The J[PN(X)H] spin coupling constant is approximatively twice as large for X = N as for X = C.