Hydrogen-bonded sheets in the 1:1 cocrystal of biphenyl-4,4'-dicarboxylic acid with 2,5-di-4-pyridyl-1,3,4-oxadiazole.

The combination of biphenyl-4,4'-dicarboxylic acid (H2bpa) and the bent dipyridyl base 2,5-di-4-pyridyl-1,3,4-oxadiazole (4-bpo) in a 1:1 molar ratio leads to the formation of the molecular co-crystal (H2bpa).(4-bpo) or C14H10O4.C12H8N4O. The asymmetric unit contains one-half of an H2bpa unit lying across a centre of inversion and one-half of a 4-bpo molecule lying across a twofold rotation axis. Intermolecular O-H...N interactions connect the acid and base molecules to form a one-dimensional zigzag chain. Through further weak C-H...O hydrogen bonds between adjacent chains, a two-dimensional sheet-like supramolecular network is afforded. As an extended analogue of terephthalic acid (H2tp), the backbone geometry of H2bpa has an evident influence on the hydrogen-bonding pattern of the title co-crystal compared with that of (H2tp).(4-bpo).