Crystal structure of 4,4′-(ethene-1,2-di­yl)dipyridinium bis­(3-carb­oxy­benzene­sulfonate)

In the title mol­ecular salt, C₁₂H₁₂N₂²⁺·2C₇H₅O₅S⁻, the complete dication is generated by crystallographic inversion symmetry. In the anion, the sulfonic acid group is deprotonated and the dihedral angle between the planes of the carb­oxy­lic acid group and the benzene ring is 12.41 (11)°. In the crystal, the anions are linked into inversion dimers by pairs of O—H...O hydrogen bonds, which generate R₂²(16) loops. The dications link the anion dimers into [10-2] chains via N—H...O hydrogen bonds.