Phosphoramides: Synthesis, spectroscopy, and x-ray crystallography

Article abstract of DOI:10.1002/hc.21107

A series of new phosphoramides with general formula RP(O)X₂, where R = amino/p-methylphenoxy and X = amine, were synthesized and characterized by ¹H, ¹³C, ³¹P nuclear magnetic resonance (NMR), and infrared (IR) spectroscopy and elemental analysis. The ³¹P{¹H} NMR spectra show that among compounds 7-9 containing 2-, 3-, and 4-aminopyridinyl moieties, respectively, the shielding order of the P atom decreases as 7 > 9 > 8. Also, the structure of compound 7 was determined by X-ray crystallography. In this structure, repeated noncentrosymmetric dimers are formed by two strong intermolecular N(1)-H(1N).N(2) and N(3)-H(3N).O(1) hydrogen bonds. Taking into account weak intermolecular C(17)-H(17C).N(4), C(17)-H(17E).N(4), C(2)-H(2A).O(2), and also weak aromatic C - H.C interactions, a three-dimensional polymeric chain is created in the crystalline network. The density functional theory calculations at B3LYP, B3PW91, and M06 levels using the 6-31+G * basis set were in good agreement with the X-ray crystallography data.