2-Carboxy-1-(3-nitrophenyl)ethanaminium perchlorate

In the cation of the title compound, C9H11N2O4 +·ClO4 −, the conformation is stabilized by an intramolecular N—H⋯O hydrogen bond. In the crystal packing, centrosymmetrically related cations interact through intermolecular O—H⋯O hydrogen bonds involving the carboxy groups, forming dimers. The dimers and the perchlorate anions are further linked into layers parallel to the ab plane by C—H⋯O and N—H⋯O hydrogen-bonding interactions.