The co-crystal N,N'-bis-[(pyridin-1-ium-2-yl)meth-yl]ethane-dithio-amide bis-(2,6-di-nitro-benzoate)-2,6-di-nitro-benzoic acid (1/4).

The asymmetric unit of title co-crystal, C14H16N4S2 (2+)·2C7H3N2O6 (-)·4C7H4N2O6, comprises a centrosymmetric dipyridinium dication, a 2,6-di-nitro-benzoate anion and two independent 2,6-di-nitro-benzoic acid mol-ecules. The pyridin-ium rings are each approximately perpendicular to the central di-thio-amide unit [dihedral angle = 80.67 (12)°]. The carboxyl-ate/carb-oxy-lic 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 supra-molecular chains along [1-10], featuring O-H⋯O(carboxyl-ate) and pyridinium-N-H⋯O hydrogen bonds. These are consolidated into a three-dimensional architecture by thio-amide-nitro N-H⋯O, C-H⋯O and π-π [inter-centroid distance = 3.524 (2) Å] inter-actions. One of the nitro O atoms was refined over two sites; the major site was 0.65 (7) occupied.