title: Three one-dimensional coordination polymers based on 1,1'-bis(pyridin-4-ylmethyl)-2,2'-bi-1H-benzimidazole and HgX2 (X = Cl, Br and I).
abstract: A new 2,2'-bi-1H-benzimidazole bridging organic ligand, namely 1,1'-bis(pyridin-4-ylmethyl)-2,2'-bi-1H-benzimidazole, C26H20N6, L or (I), has been synthesized and used to create three new one-dimensional coordination polymers, viz. catena-poly[[dichloridomercury(II)]-μ-1,1'-bis(pyridin-4-ylmethyl)-2,2'-bi-1H-benzimidazole], [HgCl2(C26H20N6)]n, (II), and the bromido, [HgBr2(C26H20N6)]n, (III), and iodido, [HgI2(C26H20N6)]n, (IV), analogues. Free ligand L crystallizes with two symmetry-independent half-molecules in the asymmetric unit and each L molecule resides on a crytallographic inversion centre. In structures (II)-(IV), the L ligand is also positioned on a crystallographic inversion centre, whereas the Hg centre resides on a crystallographic twofold axis. Compound (I) adopts an anti conformation in the solid state and forms a two-dimensional network in the crystallographic bc plane via π-π and C-H...π interactions. The three Hg(II) coordination complexes, (II)-(IV), have one-dimensional zigzag chains composed of L and HgX2 (X = Cl, Br and I), and the Hg(II) centres are in a distorted tetrahedral [HgX2N2] coordination geometry. Complexes (III) and (IV) are isomorphous, whereas complex (II) displays an interesting conformational difference from the others, i.e. a twist in the flexible bridging ligand.
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, People's Republic of China.
authors.forename: Ai-Guo
authors.initials: AG
authors.lastname: Li
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, People's Republic of China.
authors.forename: Qi-Kui
authors.initials: QK
authors.lastname: Liu
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, People's Republic of China.
authors.forename: Yan-An
authors.initials: YA
authors.lastname: Li
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, People's Republic of China.
authors.forename: Zhi-Xian
authors.initials: ZX
authors.lastname: Liu
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, People's Republic of China.
authors.forename: Yu-Bin
authors.initials: YB
authors.lastname: Dong
keywords: 2,2′-bi-1H-benzimidazole; MOCPs; crystal structure; one-dimensional coordination polymers