Redetermined structure of 4,4′-bi­pyridine–1,4-phenyl­enedi­acetic acid (1/1) co-crystal

The asymmetric unit of the title 1:1 co-crystal, C(10)H(8)N(2)·C(10)H(10)O(4), consists of one half-mol­ecule each of 4,4′-bi­pyridine and 1,4-phenyl­enedi­acetic acid: the complete mol­ecules are generated by crystallographic inversion centres. The dihedral angle between the –CO(2)H group and the benzene ring in the diacid is 73.02 (7)°. In the crystal, the components are linked by O—H⋯N hydrogen bonds, generating [1-2-1] chains of alternating amine and carb­oxy­lic acid mol­ecules. The chains are cross-linked by C—H⋯O inter­actions. This structure was previously incorrectly described as a (C(10)H(10)N(2))(2+)·(C(10)H(8)O(4))(2−) mol­ecular salt [Jia et al. (2009 ▸). Acta Cryst. E65, o2490–o2490].