Crystal structure of a novel one-dimensional zigzag chain-like cobalt(II) coordination polymer constructed from 4,4'-bi-pyridine and 2-hy-droxy-benzoate ligands.

A novel one-dimensional zigzag chain-like CoII coordination polymer constructed from 4,4'-bi-pyridine (4,4'-bpy) and 2-hy-droxy-benzoate (2-OHbenz) ligands, namely, catena-poly[[(4,4'-bi-pyridine-κN)-(μ-2-hy-droxy-benzoato-κ2 O:O')(2-hy-droxy-benzoato-κ2 O,O')cobalt(II)]-μ-4,4'-bi-pyridine-κ2 N:N'-[aquahemi(μ-4,4'-bi-pyridine-κ2 N:N')(2-hy-droxy-benzoato-κO(2-hy-droxy-benzoato-κ2 O:O')cobalt(II)], [Co2(C7H5O3)4(C10H8N2)2.5(H2O)] n , has been synthesized by reacting cobalt(II) nitrate trihydrate, 4,4'-bpy and 2-hy-droxy-benzoic acid in a mixture of water and methanol at room temperature. There are two independent CoII centers, Co1 and Co2, in the asymmetric unit, revealing a distorted octa-hedral geometry with chromophore types of [CoN2O4] and [CoN2O3O'], respectively. The Co1 ions are doubly bridged by 2-OHbenz ligands with syn-anti coordination mode, generating a dinuclear unit. The bridging 4,4'-bpy ligands connect these dinuclear units and the mononuclear Co2 chromophores, providing a one-dimensional alternating zigzag chain-like structure. In the crystal, inter-molecular hydrogen bonds, C-H⋯π and π-π stacking inter-actions are observed and these help to consolidate the packing. In addition, the physical properties of the title compound are reported.