5-Chloro-1H-indole-3-carboxylic acid

Abstract

In the title compound, C9H6ClNO2, the carboxyl group is twisted from the indole ring system by 9.00 (8)°. In the crystal, inversion dimers linked by pairs of O—H...O hydrogen bonds generate R22(8) loops and N—H...O hydrogen bonds link the dimers into (001) sheets. Aromatic π–π stacking interactions [centroid–centroid distance = 3.7185 (12) A °] are also observed.