Structure of the mercury(II) mixed-halide (Br/Cl) complex of 2,2′-(5-tert-butyl-1,3-phenylene)bis(1-pentyl-1H-benzo[d]imidazole)

Abstract

The mercury(II) complex of 2,2′-(5-tert-butyl-1,3-phenylene)bis(1-pentyl-1H-benzimidazole), namelycatena-poly[[dihalogenidomercury(II)]-μ-2,2′-(5-tert-butyl-1,3-phenylene)bis(1-pentyl-1H-benzimidazole)-κ2N3:N3′], [HgBr1.52Cl0.48(C34H42N4)],2, has a polymeric structure bridgingviathe N atoms from the benzimidazole moieties of the ligand. The compound crystallizes in the orthorhombic space groupPca21and is a racemic twin [BASF = 0.402 (9)]. The geometry around the HgIIatom is distorted tetrahedral, with the HgIIatom coordinated to two N atoms, one Br atom, and a fourth coordination site is occupied by a mixed halide (Br/Cl). For the two ligands in the asymmetric unit, there is disorder with one of the twotert-butyl groups and benzimidazole moieties showing twofold disorder, with occupancy factors of 0.57 (2):0.43 (2) for thetert-butyl group and 0.73 (3):0.27 (3) for the benzimidazole group. In addition, there is threefold disorder for two of the fourn-pentyl groups, with occupancy factors of 0.669 (4):0.177 (4):0.154 (4) and 0.662 (4):0.224 (4):0.154 (4), respectively. The molecules form a one-dimensional helical polymer propagating in theb-axis direction. The helices are held together by intra-strand C—H...Br and C—H...Cl interactions. Each strand is further linked by inter-strand C—H...Br and C—H...Cl interactions. In addition, there are weak C—H...N inter-strand interactions which further stabilize the structural arrangement.