2-Amino­benzoic acid–4,4′-bi­pyridine (2/1)

The asymmetric unit of title co-crystal, C(10)H(8)N(2)·2C(7)H(7)NO(2), comprises a centrosymmetric 4,4′-bi­pyridine mol­ecule, and a 2-amino­benzoic acid mol­ecule in a general position. The latter is effectively planar [C—C—C—O torsion angle = 5.0 (3)°] owing to an intra­molecular N—H⋯O(carbon­yl) hydrogen bond. Three-mol­ecule aggregates are formed via O—H⋯N(pyrid­yl) hydrogen bonds and these are connected into supra­molecular layers in the bc plane by N—H⋯O(carbon­yl) hydrogen bonds and π–π inter­actions between pyridyl and benzene rings [inter-centroid distance = 3.634 (2) Å]. Layers are connected along the a axis by weak π–π inter­actions between benzene rings [3.964 (2) Å].