Syed Sabrina, Halim Siti Nadiah Abdul, Jotani Mukesh M, Tiekink Edward R T
Department of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia.
Department of Physics, Bhavan's Sheth R. A. College of Science, Ahmedabad, Gujarat 380001, India.
Acta Crystallogr E Crystallogr Commun. 2016 Jan 1;72(Pt 1):76-82. doi: 10.1107/S2056989015024068.
The title 2:1 co-crystal, 2C7H5NO4·C14H14N4O2, in which the complete di-amide mol-ecule is generated by crystallographic inversion symmetry, features a three-mol-ecule aggregate sustained by hydroxyl-O-H⋯N(pyrid-yl) hydrogen bonds. The p-nitro-benzoic acid mol-ecule is non-planar, exhibiting twists of both the carb-oxy-lic acid and nitro groups, which form dihedral angles of 10.16 (9) and 4.24 (4)°, respectively, with the benzene ring. The di-amide mol-ecule has a conformation approximating to a Z shape, with the pyridyl rings lying to either side of the central, almost planar di-amide 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-mol-ecule aggregates are linked into a linear supra-molecular ladder sustained by amide-N-H⋯O(nitro) hydrogen bonds and orientated along [10-4]. The ladders are connected into a double layer via pyridyl- and benzene-C-H⋯O(amide) inter-actions, which, in turn, are connected into a three-dimensional architecture via π-π stacking inter-actions between pyridyl and benzene rings [inter-centroid distance = 3.6947 (8) Å]. An evaluation of the Hirshfeld surfaces confirm the importance of inter-molecular inter-actions involving oxygen atoms as well as the π-π inter-actions.
标题为2:1的共晶体2C₇H₅NO₄·C₁₄H₁₄N₄O₂中，完整的二酰胺分子由晶体学倒转对称性产生，其特征是通过羟基 - O - H⋯N（吡啶基）氢键形成三分子聚集体。对硝基苯甲酸分子是非平面的，羧酸基团和硝基均存在扭曲，它们与苯环分别形成10.16 (9)°和4.24 (4)°的二面角。二酰胺分子的构象近似Z形，吡啶环位于中心几乎平面的二酰胺残基两侧（八个原子的均方根偏差为0.025 Å），并与其形成77.22 (6)°的二面角。在晶体中，三分子聚集体通过酰胺 - N - H⋯O（硝基）氢键连接成线性超分子阶梯，并沿[10 - 4]方向排列。这些阶梯通过吡啶基和苯 - C - H⋯O（酰胺）相互作用连接成双层结构，进而通过吡啶环和苯环之间的π - π堆积相互作用（质心间距 = 3.6947 (8) Å）连接成三维结构。对Hirshfeld表面的评估证实了涉及氧原子的分子间相互作用以及π - π相互作用的重要性。
