2-Chloro-4-nitro­benzoic acid as a coformer with pharmaceutical cocrystals and mol­ecular salts

A series of five binary com­plexes, i.e. three cocrystals and two mol­ecular salts, using 2-chloro-4-nitro­benzoic acid as a coformer have been produced with five commonly available com­pounds, some of pharmaceutical relevance, namely, 2-chloro-4-nitro­benzoic acid-isonicotinamide (1/1), C 7 H 4 ClNO 4 ·C 6 H 6 N 2 O, 2-chloro-4-nitro­benzoic acid-3,3-di­ethyl­pyridine-2,4(1H,3H)-dione (2/1), 2C 7 H 4 ClNO 4 ·C 9 H 13 NO 2, 2-chloro-4-nitro­benzoic acid-pyrrolidin-2-one (1/1), C 7 H 4 ClNO 4 ·C 4 H 7 NO, 2-carb­oxy­piperidinium 2-chloro-4-nitro­benzoate, C 6 H 12 NO 2 - ·C 7 H 3 ClNO 4 -, and (2-hy­droxy­eth­yl)ammonium 2-chloro-4-nitro­benzoate, C 2 H 8 NO + ·C 7 H 3 ClNO 4 -. The coformer falls under the classification of a 'generally regarded as safe' com­pound. All five com­plexes make use of a number of different heteromeric hydrogen-bonded inter­actions. Inter­molecular potentials were evaluated using the CSD-Materials module.