5,12-Dimethyl­pyrazino­[1,2-a:4,5-a′]dibenzimidazole-5,12-diium dichloride dihydrate

The title hydrated salt, C₁₈H₁₈N₄²⁺·2Cl⁻·2H₂O, sits about an inversion centre, such that the asymmetric unit contains one half-mol­ecule. In the crystal, hydrogen bonds occur between the water mol­ecules and chloride anions, and there is π–π stacking of the benzene and imidazole rings of inversion-related pairs of mol­ecules, with a centroid–centroid distance of 3.704 (17) Å.