3,3'-[1,2-Phenylenebis(methylene)]bis(1-propylbenzimidazolium) dibromide hemihydrate

Acta Crystallographica Section E

Structure Reports Online

Volume 68, Part 2 (February 2012)

organic compounds

tk5046 scheme

Acta Cryst. (2012). E68, o466-o467 [ doi:10.1107/S1600536812001596 ]

3,3'-[1,2-Phenylenebis(methylene)]bis(1-propylbenzimidazolium) dibromide hemihydrate

M. A. Iqbal, R. A. Haque, H.-K. Fun and T. S. Chia

Abstract: The asymmetric unit of the title compound, C₂₈H₃₂N₄²⁺·2Br^-·0.5H₂O, contains one 3,3'-[1,2-phenylenebis(methylene)]bis(1-propylbenzimidazolium) cation, two bromide anions and one half-molecule of water. In the crystal, the whole 3,3'-[1,2-phenylenebis(methylene)]bis(1-propylbenzimidazolium) cation and one of the bromide anions are each disordered over two positions with site-occupancy ratios of 0.751 (6):0.249 (6) and 0.680 (8):0.320 (8). For the major component of the disordered cation, the central benzene ring forms dihedral angles of 83.6 (5) and 88.2 (4)° with its adjacent imidazole rings, while these angles for the minor component are 89.2 (15) and 84.9 (13)°. In the crystal, the cations and anions are linked by C-HBr hydrogen bonds into dimers and then stacked along the c axis. The crystal packing is further stabilized by C-H [pi] and [pi] - [pi] interactions [shortest centroid-centroid distance = 3.646 (4) Å].