Crystal structures of the two isomeric hydrogen-bonded cocrystals 2-chloro-4-nitrobenzoic acid–5-nitroquinoline (1/1) and 5-chloro-2-nitrobenzoic acid–5-nitroquinoline (1/1)
The structures of two isomeric compounds of 5-nitroquinoline with chloro- and nitro-substituted benzoic acid, namely, 2-chloro-4-nitrobenzoic acid–5-nitroquinoline (1/1), (I), and 5-chloro-2-nitrobenzoic acid–5-nitroquinoline (1/1), (II), both C7H4ClNO4·C9H6N2O2, have been determined at 190 K. In each compound, the acid and base molecules are held together by an O—H...N hydrogen bond. In the crystal of (I), the hydrogen-bonded acid–base units are linked by a C—H...O hydrogen bond, forming a tape structure along [1\overline{2}0]. The tapes are stacked into a layer parallel to the ab plane via N—O...π interactions between the nitro group of the base molecule and the quinoline ring system. The layers are further linked by other C—H...O hydrogen bonds, forming a three-dimensional network. In the crystal of (II), the hydrogen-bonded acid–base units are linked into a wide ribbon structure running along [1\overline{1}0] via C—H...O hydrogen bonds. The ribbons are further linked via another C—H...O hydrogen bond, forming a layer parallel to (110). Weak π–π interactions [centroid–centroid distances of 3.7080 (10) and 3.7543 (9) Å] are observed between the quinoline ring systems of adjacent layers. Hirshfeld surfaces for the 5-nitroquinoline molecules of the two compounds mapped over shape index and d norm were generated to visualize the weak intermolecular interactions.