2-Amino-terephthalic acid-4,4'-bipyridine (1/1).

The asymmetric unit of the title compound, C(10)H(8)N(2)·C(8)H(7)NO(4), contains two half-mol-ecules, which constitute a 1:1 co-crystal. The 2-amino-terephthalic acid mol-ecule is situated on an inversion center being disordered between two orientations in a 1:1 ratio. In the 4,4'-bipyridine mol-ecule, which is situated on a twofold rotational axis, the two pyridine rings form a dihedral angle of 37.5 (1)°. In the crystal, mol-ecules are held together via inter-molecular N-H⋯O and O-H⋯N hydrogen bonds. The crystal packing exhibits π-π inter-actions between the aromatic rings with a centroid-centroid distance of 3.722 (3) Å.