One-dimensional coordination polymers of copper(II), cobalt(II), zinc(II) and cadmium(II) with glutarate and N-methylimidazole

Four coordination polymers, namely, {[Co(μ-glu)(nmim)2]·2H2O}n (1), [Cu(μ-glu)(nmim)2]n (2), {[Zn(μ-glu)(nmim)2]·2H2O}n (3) and [Cd(μ-glu)(nmim)2] (4) (glu = glutarate, nmim = N-methylimidazole), have been synthesized and characterized by elemental analysis, IR spectroscopy, thermal analysis and single-crystal X-ray diffraction techniques. Moreover, the photoluminescence properties of 3 and 4 have been investigated. Structural analyses reveal that all the complexes exhibit one-dimensional (1D) linear chain structures bridged by the glutarate ligand, which further form 3D supramolecular networks via intermolecular π⋯π, C–H⋯π and weak hydrogen bonding interactions. In the complexes, the glu ligand adopts the bis-monodentate and bis-bidentate bridging modes through two and four carboxylate oxygen atoms, respectively. The distorted octahedral geometry for complexes 2 and 4 and tetrahedral geometry for complexes 1 and 3 are completed by two nmim ligands. Complexes 3 and 4 exhibit a blue emission in the solid state at room temperature.

Graphical abstractIn this work, four glutarate (glu) complexes were synthesized and characterized. Structural analyses reveal that all the complexes exhibit one-dimensional (1D) linear chains bridged by the glutarate ligand, which further form 3D supramolecular networks via intermolecular π⋯π, C–H⋯π and weak hydrogen bonding interactions. In the complexes, the glu ligand exhibits bis(monodentate) and bis(bidentate) bridging modes, being coordinated through two and four carboxylate oxygen atoms.Figure optionsDownload full-size imageDownload as PowerPoint slide