(E)-1,1'-Bis[(E)-but-2-en-yl]-3,3'-(propane-1,3-di-yl)bis-(1H-benzimidazol-3-ium) dibromide monohydrate.

The title compound, C(25)H(30)N(4) (2+)·2Br(-)·H(2)O, was synthesized from 1,1'-propyl-enedibenzimidazole and (E)-1-bromo-but-2-ene in dimethyl-formamide solution. The two benzimidazole ring systems are essentially planar, with maximum deviations of 0.011†(4) and 0.023†(3)†à . The dihedral angle between these two ring systems is 25.87†(15)°. The crystal structure is stabilized by inter-molecular O-H⋯Br and C-H⋯Br hydrogen-bonding inter-actions. Atmospheric water was incorporated into the crystal structure.