Phosphoric amides.15N NMR study of the P—N bonding in acyclic and cyclic compounds

31P and 15N NMR spectra of 11 cyclic and non-cyclic phosphoramidates were measured. Comparison of the closely related structures demonstrated correlation between the bond angles at nitrogen and the 15N NMR chemical shifts and the 1J(P,N) coupling constants. 15N NMR parameters allowed the exo- and endocyclic nitrogens to be distinguished and could be related to the hydrolytic stability of the P—N bonds. © 1997 John Wiley & Sons, Ltd.