N,N-Dimethyl-N′,N′′-diphenylphosphoric triamide

In the title compound, C14H18N3OP, a crystallographic mirror plane bisects the molecule (the C,N,C atoms of the dimethylamido moiety and the P=O unit lie on the mirror plane). The P atom has a distorted tetrahedral geometry; the bond angles at P are in the range 98.98 (11)–115.28 (7)°. In the crystal, the O atom of the P=O group acts as a double hydrogen-bond acceptor for two symmetry-equivalent N—H⋯O hydrogen bonds, building [001] chains containing R 2 1(6) loops.

In the title compound, C 14 H 18 N 3 OP, a crystallographic mirror plane bisects the molecule (the C,N,C atoms of the dimethylamido moiety and the P O unit lie on the mirror plane). The P atom has a distorted tetrahedral geometry; the bond angles at P are in the range 98.98 (11)-115.28 (7) . In the crystal, the O atom of the P O group acts as a double hydrogen-bond acceptor for two symmetry-equivalent N-HÁ Á ÁO hydrogen bonds, building [001] chains containing R 2 1 (6) loops.
The tetrahedral geometry of the phosphorus atom is significantly distorted as it has been noted for the other phosphoric triamides: the bond angles at the P atom vary in the range from 98.98 (11) [N1 i -P1-N1; symmetry code (i): -x, y, z] to 115.28 (7) The O atom of the P═O group acts as a double hydrogen-bond acceptor  to form the [N-H] 2 ···O(P) grouping within a 1-D hydrogen-bonded arrangement along the c axis (Fig. 2, Table 1).
Synthesis of title compound: to a solution of ((CH 3 ) 2 N)P(O)Cl 2 (3.7 mmol) in CH 3 CN (15 ml), a solution of aniline (14.8 mmol) in CH 3 CN (25 ml) was added at 273 K. After 4 h stirring, the solvent was removed and product was washed with deionized water and recrystallized from CH 3 CN at room temperature to yield colourless rods.

Refinement
The H4, H11, H12 and H13 were found in difference Fourier maps and refined with isotropic displacement parameters. The others hydrogen atom positions of the C-H and N-H units were calculated and refined in a riding-model with appropriate HFIX command in SHELXL-97. Fig. 1. The molecular structure of the title compound with ellipsoids shown at the 50% probability level.

Figures
supplementary materials sup-2  Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating Rfactors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.