Crystal structure of zwitterionic 3,3′-[1,1′-(butane-1,4-di­yl)bis­(1H-imidazol-3-ium-3,1-di­yl)]bis­(propane-1-sulfonate) dihydrate

The crystal structure of the title compound, C(16)H(26)N(4)O(6)S(2)·2H(2)O, a water-soluble di-N-heterocyclic carbene ligand precursor was determined using a single crystal grown by the slow cooling of a hot N,N-di­methyl­formamide solution of the compound. The dihydrate crystallizes in the monoclinic space group P2(1)/c, with half of the zwitterionic mol­ecule and one water mol­ecule of crystallization in the asymmetric unit. The remaining part of the mol­ecule is completed by inversion symmetry. In the mol­ecule, the imidazole ring planes are parallel with a plane-to-plane distance of 2.741 (2) Å. The supra­molecular network is consolidated by hydrogen bonds of medium strength between the zwitterionic mol­ecules and the water mol­ecules of crystallization, as well as by π–π stacking inter­actions between the imidazole rings of neighbouring mol­ecules and C—H⋯O hydrogen-bonding inter­actions.