Crystal structures of two bis-carbamoyl-methyl-phosphine oxide (CMPO) compounds.

Two bis-carbamoyl-methyl-phosphine oxide compounds, namely {[(3-{[2-(di-phen-yl-phosphino-yl)ethanamido]-meth-yl}benz-yl)carbamo-yl]meth-yl}di-phenyl-phos-phine oxide, C(36)H(34)N(2)O(4)P(2), (I), and diethyl [({2-[2-(di-eth-oxy-phosphino-yl)ethanamido]-eth-yl}carbamo-yl)meth-yl]phospho-nate, C(14)H(30)N(2)O(8)P(2), (II), were synthesized via nucleophilic acyl substitution reactions between an ester and a primary amine. Hydrogen-bonding inter-actions are present in both crystals, but these inter-actions are intra-molecular in the case of compound (I) and inter-molecular in compound (II). Intra-molecular π-π stacking inter-actions are also present in the crystal of compound (I) with a centroid-centroid distance of 3.9479†(12)†à and a dihedral angle of 9.56†(12)°. Inter-molecular C-H⋯π inter-actions [C⋯centroid distance of 3.622†(2)†à , C-H⋯centroid angle of 146°] give rise to supra-molecular sheets that lie in the ab plane. Key geometric features for compound (I) involve a nearly planar, trans-amide group with a C-N-C-C torsion angle of 169.12†(17)°, and a torsion angle of -108.39†(15)° between the phosphine oxide phospho-rus atom and the amide nitro-gen atom. For compound (II), the electron density corresponding to the phosphoryl group was disordered, and was modeled as two parts with a 0.7387†(19):0.2613†(19) occupancy ratio. Compound (II) also boasts a trans-amide group that approaches planarity with a C-N-C-C torsion angle of -176.50†(16)°. The hydrogen bonds in this structure are inter-molecular, with a D⋯A distance of 2.883†(2)†à and a D-H⋯A angle of 175.0†(18)° between the amide hydrogen atom and the P=O oxygen atom. These non-covalent inter-actions create ribbons that run along the b-axis direction.