Zn(μ- l)Cl 2] ∞: a one-dimensional (1-D) zigzag coordination chain exhibiting unique two-dimensional (2D) hydrogen-bonding supramolecular architecture

Abstract

Self-assembly of the versatile bridging ligand 2,5-bis(3-pyridyl)-1,3,4-oxadiazole ( l) with ZnCl 2 in CHCl 3–H 2O medium affords a neutral one-dimensional zigzag coordination polymer [Zn(μ- l)Cl 2] ∞ ( 1), which has been characterized by IR, elemental analyses, thermogravimetric analysis (TGA) and X-ray diffraction techniques. The crystal structure of 1 reveals that the ligand molecules bridge the tetrahedral Zn II centers (ZnN 2Cl 2) in the unprecedented transoid conformation, forming a one-dimensional zigzag coordination chain. The inter-chain C–H···Cl hydrogen bonds between the pyridine rings and the coordinated chloride anions extend these 1-D coordination frameworks to result in a novel 2-D supramolecular architecture, and there exist significant edge-to-edge π–π stacking interactions between the inter-chain neighboring pyridyl rings of the ligand, which may further stabilize this structure.