A structural and theoretical study of the intermolecular interactions in 8‐hydroxyquinolinium‐7‐carboxylate monohydrate

In the title compound, C₁₀H₇NO₃·H₂O, the zwitterionic organic molecules and the water molecules are connected by N—H...O and O—H...O hydrogen bonds to form ribbons, and π–π stacking interactions expand these ribbons into a three‐dimensional net. The energies of these hydrogen bonds adopt values typical for mildly weak interactions (3.33–7.75 kcal mol^?1; 1 kcal mol^?1 = 4.184 kJ mol^?1). The total π–π stacking interactions between aromatic molecules can be classified as mildly strong (energies of 15.3 and 33.9 kcal mol^?1), and they are made up of multiple constituent π–π interactions between six‐membered rings. The short intermolecular C—H...O contact between two zwitterionic molecules is nonbonding in character.