Crystal Structure Of Zwitterionic 3,3 '-[1,1 '-(Butane-1,4-Diyl)Bis(1h-Imidazol-3-Ium-3,1-Diyl)]Bis(Propane-1-Sulfona Te) Dihydrate

The crystal structure of the title compound, C16H26N4O6S2 center dot 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) angstrom. 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 pi-pi stacking interactions between the imidazole rings of neighbouring molecules and C-H center dot center dot center dot O hydrogen-bonding interactions.