Figure 1 Mol­ecular structures of the components of (I), showing atom-labelling scheme and displacement ellipsoids at the 70% probability level: (a) the 2,6-di­nitro­benzoate anion, and (b) the 4-[2-(pyridin-1-ium-4-yl)eth­yl]pyridin-1-ium dication (unlabelled atoms are related by the symmetry operation -x, 2 - y, 1-z).  [article HTML]