Structure of 2,2'-(5-tert-butyl-1,3-phenyl-ene)bis-(1-pentyl-1H-benzimidazol-3-ium) tetra-chlorido-mercurate(II).

In the title salt, (C(34)H(44)N(4))[HgCl(4)], the [C(34)H(44)N(4)](2+) cations and [HgCl(4)](2-) anions are linked by N-H⋯Cl hydrogen bonds. One of the two n-pentyl side chains was refined as disordered over two sets of sites, with occupancies of 0.733†(18) and 0.267†(18). The geometry around the Hg(II) atom in the [HgCl(4)](2-) anion is distorted tetra-hedral, with bond angles ranging from 98.16†(3) to 120.68†(3)°. In the [HgCl(4)](2-) anion, there are two short Hg-Cl bonds [2.4120†(9) and 2.4171†(11)†à ], one inter-mediate Hg-Cl bond [2.4716†(12)†à ] and one long Hg-Cl bond [2.6579†(13)†à ] for the Cl atom involved in a trifurcated hydrogen bond as an acceptor, including two N-H⋯Cl⋯H-N interactions as well as one C-H⋯Cl inter-action. There are several C-H⋯Cl inter-actions, with C⋯Cl distances ranging from 3.492†(3) to 3.796†(3)†à . These link the cations and anions into a zigzag chain along the c-axis direction. In addition, there are Cl⋯Cl halogen bonds, as well as π-π inter-actions, with centroid-to-centroid distances of 3.4765†(18)†à , which link one of the two benzimidazole moieties into dimeric units.