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