The co-crystal N,N′-bis­[(pyridin-1-ium-2-yl)meth­yl]ethane­dithio­amide bis­(2,6-di­nitro­benzoate)–2,6-di­nitro­benzoic acid (1/4)

The asymmetric unit of title co-crystal, C(14)H(16)N(4)S(2) (2+)·2C(7)H(3)N(2)O(6) (−)·4C(7)H(4)N(2)O(6), comprises a centrosymmetric dipyridinium dication, a 2,6-di­nitro­benzoate anion and two independent 2,6-di­nitro­benzoic acid mol­ecules. The pyridin­ium rings are each approximately perpendicular to the central di­thio­amide unit [dihedral angle = 80.67 (12)°]. The carboxyl­ate/carb­oxy­lic acid groups are approximately perpendicular to the benzene ring to which they are attached [dihedral angles = 78.85 (16), 81.46 (19) and 71.28 (15)°]. By contrast, the major twist exhibited by a nitro group is manifested in a dihedral angle of 32.66 (17)°. The most prominent feature of the crystal packing is linear supra­molecular chains along [1-10], featuring O—H⋯O(carboxyl­ate) and pyridinium-N—H⋯O hydrogen bonds. These are consolidated into a three-dimensional architecture by thio­amide–nitro N—H⋯O, C—H⋯O and π–π [inter-centroid distance = 3.524 (2) Å] inter­actions. One of the nitro O atoms was refined over two sites; the major site was 0.65 (7) occupied.