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

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—H...Br hydrogen bonds into dimers and then stacked along the c axis. The crystal packing is further stabilized by C—H...π and π–π inter­actions [shortest centroid–centroid distance = 3.646 (4) Å].

3,3′-[1,2-Phenyl­enebis(methyl­ene)]bis­(1-ethyl­benzimidazolium) dibromide

In the title mol­ecular salt, C₂₆H₂₈N₄²⁺·2Br⁻, the central benzene ring makes dihedral angles of 76.75 (11) and 82.40 (10)° with the pendant benzimidazole rings. The corresponding angle between the benzimidazole rings is 57.03 (9)°. In the crystal, the cations and anions are linked via C—H...Br hydrogen bonds, forming sheets lying parallel to the bc plane. The crystal structure also features weak C—H...π inter­actions.

3,3′-[1,4-Phenyl­enebis(methyl­ene)]­bis­(1-propyl­benzimidazolium) dichloride dihydrate

The asymmetric unit of the title compound, C₂₈H₃₂N₄²⁺·2Cl⁻·2H₂O, contains half of a 3,3′-[1,4-phenyl­enebis(methyl­ene)]bis­(1-propyl­benzimidazolium) cation, one chloride anion and one water mol­ecule. The complete cation is generated by a crystallographic inversion center. The central benzene ring forms a dihedral angle of 66.06 (11)° with its adjacent benzimidazolium ring system. In the crystal, the cations, anions and water mol­ecules are linked by O—H...Cl, C—H...O and C—H...Cl hydrogen bonds into a three-dimensional network. The crystal packing is further stabilized by π–π inter­actions, with centroid–centroid distances of 3.5561 (15) and 3.6708 (15) Å.

3,3′-[1,2-Phenyl­enebis(methyl­ene)]bis­(1-octylbenzimidazolium) dibromide monohydrate

In the title hydrated mol­ecular salt, C₃₈H₅₂N₄²⁺·2Br⁻·H₂O, the central benzene ring of the dication makes dihedral angles of 89.47 (13) and 72.69 (12)° with the pendant benzimidazol-3-ium rings. The conformations of the octyl side chains are completely different. In the crystal, the components are linked by O—H...Br, C—H...Br and C—H...O hydrogen bonds into a two-dimensional network lying parallel to the ac plane. Aromatic π–π stacking inter­actions are also observed [shortest centroid-to-centroid separation = 3.5047 (16) Å].

3,3′-[1,2-Phenyl­enebis(methyl­ene)]bis­(1-ethyl-1H-benzimidazol-1-ium) bis­(hexa­flourophosphate)

In the title compound, C₂₆H₂₈N₄²⁺·2PF₆⁻, the complete cation is generated by a crystallographic twofold axis. The benz­imidazole ring is almost planar (r.m.s. deviation = 0.0207 Å) and makes dihedral angles of 50.12 (2)° with its symmetry-related component and 65.81 (2)° with the central benzene ring. In the crystal, mol­ecules are linked into a three-dimensional network by C—H...F inter­actions. A π–π inter­action with a centroid–centroid distance of 3.530 (1) Å is observed. Four F atoms of the hexa­fluoro­phosphate anion are disordered over two sets of sites in a 0.889 (6):0.111 (6) ratio.