The asymmetric unit of the title compound, C(5)H(7)N(2) (+)·C(7)H(4)NO(4) (-)·C(7)H(5)NO(4), consists of an amino-pyridinium cation, a 4-nitro-benzoate anion and a neutral 4-nitro-benzoic acid mol-ecule. The pyridine ring forms dihedral angles of 64.70 (5)° and 70.37 (5)°, respectively, with the benzene rings of 4-nitro-benzoic acid and 4-nitro-benzoate. In the crystal structure, the cations, anions and the neutral 4-nitro-benzoic acid mol-ecules are linked by O-H⋯O and N-H⋯O hydrogen bonds, forming a two-dimensional network parallel to (001). Adjacent networks are cross-linked via C-H⋯O hydrogen bonds and π-π stacking inter-actions [centroid-centroid distances 3.6339 (6) and 3.6566 (6) Å].
* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.