Synthesis and Crystal structure of a New N-(2,6-dichlorobenzoyl)-N\',N\',N\",N\"-tetra(ethyl)-Phosphoric triamide Maryam Toghraee*, Mehrdad Pourayoubi Department of Chemistry, Ferdowsi University of Mashhad, Mashhad, 91779, Iran. Organophosphorus compounds are well-known as the biologically active substances [1]. Among them the anticancer activity of compounds having a C(O)NHP(O) skeleton has been studied [2]. In a recently published paper, patterns of hydrogen bonds in phosphoric triamides containing a C(O)NHP(O) skeleton have been discussed [3]. The synthesis and X-ray crystal structure of the title phosphoric triamide is a continuation of work on this family of compounds in our laboratory. Following our previous works about C(O)NHP(O)-based phosphoric triamides such as P(O)[NHC(O)CHCl2][N(CH2CH3)2]2 [3], here, the synthesis, spectroscopic characterization (by 1H, 13C, 31P NMR, IR) and crystal structure of 2,6-Cl2-C6H3C(O)NHP(O)[N(CH2CH3)2]2 are reported. Single crystals of title compound were obtained from a solution of CH3OH and CH3CN after slow evaporation at room temperature. The asymmetric unit contains four symmetrically independent molecules. In each molecule, the P—N bond lengths in the P(O)[N(CH2CH3)2]2 fragment are shorter than the other P—N bond. The P═O band lengths of 1.477(3) Å for P1, 1.482(3) Å for P2, 1.479(3) Å for P3 and 1.479(3) Å for P4 are longer than the normal P═O band length (1.45 Å). The phosphorus atoms have a disordered tetrahedral configuration; the bond angles at the P atoms are in the range of 105.20(15)˚-115.88(16)˚ for molecule P1, 104.99(15)˚-115.71(17)˚ for P2, 105.37(15)˚-115.72(17)˚ for P3 and 105.44(16)˚-114.46(18)˚ for P4. In the crystal packing, two independent dimers are formed through intermolecular P═O•••H—N hydrogen bonds, as R22(8) rings. Refrences: [1] F. Ekstrom, C. Akfur, A. Tunemalm, S. Lundberg, Biochemistry 45 (2006) 74. [2] K. Gholivand, N. Dorosti, Z. Shariatinia, F. Ghaziany, S. Sarikhani, M. Mirshahi, Med. Chem. Res. 20 (2011) 1287. [3] M. Toghraee, M. Pourayoubi, V. Divjakovic, Polyhedron 30 (2011) 1680.

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