One-Dimensional Coordination Polymers of Copper(II), Cobalt(II), Zinc(II) and Cadmium(II) with Glutarate and N-Methylimidazole

Abstract

Four coordination polymers, namely, {[Co(μ-glu)(nmim) <inf>2</inf>]·2H<inf>2</inf>O}<inf>n</inf> (1), [Cu(μ-glu)(nmim) <inf>2</inf>]<inf>n</inf> (2), {[Zn(μ-glu)(nmim)<inf>2</inf>]·2H <inf>2</inf>O}<inf>n</inf> (3) and [Cd(μ-glu)(nmim)<inf>2</inf>] (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. © 2013 Elsevier Ltd. All rights reserved.