Supramolecular assembly mediated through NH<middle dot><middle dot><middle dot>OX (X = C, N, P) hydrogen bonds and Y<middle dot><middle dot><middle dot>π (Y = Br, π) contacts: Structural/computational studies of the P(O)(NHC(O)C6H4-3-NO2)(NHC6H4-3-Br)2 phosphoric triamide

Supramolecular assembly is studied in the structure of N,N'-bis(3-bromo-phenyl)-N"-(3-nitro-benzoyl)phosphoric triamide, P(O)(NHC(O)C6H4-3-NO2)(NHC6H4-3-Br)(2), <bold>I</bold>, by X-ray crystallography combined with quantum chemical calculations. The asymmetric unit of <bold>I</bold> is composed of two symmetry-independent molecules that show differences in some torsion angles, especially the ones related to the rotation of amine moieties. The conformations of amine moieties in two molecules are considered based on the resembling P-N-C-C/OP-N-C torsion angles, which associate with the +/- sp/+sc conformations in one molecule and -sc/+sp and -sp/-sc conformations in the other molecule (sp = synperiplanar and sc = synclinal). In the crystal structure, the molecules are connected through N-H<middle dot><middle dot><middle dot>OX (X = P, C, N) hydrogen bonds, forming a two-dimensional architecture along the bc plane. The C-H<middle dot><middle dot><middle dot>O/pi<middle dot><middle dot><middle dot>pi interactions do not change the dimensionality made by N-H<middle dot><middle dot><middle dot>O hydrogen bonds, while the participation of Br<middle dot><middle dot><middle dot>pi interactions creates a three-dimensional network. The title structure represents the first observation of Br<middle dot><middle dot><middle dot>pi interaction in the C(O)NHP(O)-based family. The methods of Atoms in Molecules (AIM), Natural Bond Orbital (NBO) and Reduced Density Gradient (RDG) are used for the study of noncovalent interactions.