Three new [XC(O)NH]P(O)[N(CH2-C6H5) 2]2 phosphoric triamides (X = CClF2, 3-F-C 6H4 and 3,5-F2-C6H3): A database analysis of tertiary N-atom geometry in compounds with a C(O)NHP(O)[N] 2 core

Abstract

In the phospho-ric triamides N,N,N′,N′-tetrabenzyl-N″-(2- chloro-2,2-difluoroacetyl)phospho-ric triamide, C30H 29ClF2N3O2P, (I), N,N,N′,N′-tetrabenzyl-N″-(3-fluoro-benzo-yl)phospho-ric triamide, C35H33FN3O2P, (II), and N,N,N′,N′-tetrabenzyl-N″-(3,5-difluoro-benzo-yl)phospho-ric triamide, C35H32F2N3O2P, (III), the tertiary N atoms of the dibenzyl-amido groups have sp 2 character with minimal deviation from planarity. The sums of the three bond angles about the N atoms in (I)-(III) deviate by less than 8° from the planar value of 360°. The geometries of the tertiary N atoms in all phospho-ric triamides with C(O)NHP(O)[N]2 skeletons deposited in the Cambridge Structural Database [CSD; Allen (2002). Acta Cryst. B58, 380-388] have been examined and the bond-angle sums at the two tertiary N atoms (SUM1 and SUM2) and the parameter SUM (= SUM1 - SUM2) considered. It was found that in compounds with a considerable ΔSUM value, the more pyramidal N atoms are usually oriented so that the corresponding lone electron pair is anti with respect to the P=O group. In (I), (II) and (III), the phosphoryl and carbonyl groups, separated by an N atom, are anti with respect to each other. In the C(O)NHP(O) fragment of (I)-(III), the P - N bond is longer and the O - P - N angle is contracted compared with the other two P - N bonds and the O - P - N angles in the molecules. These effects are also seen in analogous compounds deposited in the CSD. Compounds with [C(O)NH]P(O)[N]X (X ≠ N), such as compounds with a [C(O)NH]P(O)[N][O] skeleton, have not been considered here. Also, com-pounds with a [C(O)NH]2P(O)[N] fragment have not been reported to date. In the crystal structures of all three title compounds, adjacent molecules are linked via pairs of P=O⋯H - N hydrogen bonds, forming dimers with C i symmetry. © 2012 International Union of Crystallography.