A 2:1 co-crystal ofp-nitrobenzoic acid andN,N′-bis(pyridin-3-ylmethyl)ethanediamide: crystal structure and Hirshfeld surface analysis

Abstract

The title 2:1 co-crystal, 2C7H5NO4·C14H14N4O2, in which the complete diamide molecule is generated by crystallographic inversion symmetry, features a three-molecule aggregate sustained by hydroxyl-O—H...N(pyridyl) hydrogen bonds. Thep-nitrobenzoic acid molecule is non-planar, exhibiting twists of both the carboxylic acid and nitro groups, which form dihedral angles of 10.16 (9) and 4.24 (4)°, respectively, with the benzene ring. The diamide molecule has a conformation approximating to a Z shape, with the pyridyl rings lying to either side of the central, almost planar diamide residue (r.m.s. deviation of the eight atoms being 0.025 Å), and forming dihedral angles of 77.22 (6)° with it. In the crystal, three-molecule aggregates are linked into a linear supramolecular ladder sustained by amide-N—H...O(nitro) hydrogen bonds and orientated along [10-4]. The ladders are connected into a double layerviapyridyl- and benzene-C—H...O(amide) interactions, which, in turn, are connected into a three-dimensional architectureviaπ–π stacking interactions between pyridyl and benzene rings [inter-centroid distance = 3.6947 (8) Å]. An evaluation of the Hirshfeld surfaces confirm the importance of intermolecular interactions involving oxygen atoms as well as the π–π interactions.