One-dimensional coordination polymers of Co(II) and Cd(II)-squarate with 2-methylimidazole and 4(5)-methylimidazole ligands

Two new mixed-ligand coordination polymers, {[Co(μ1,3-sq)(H2O)2(2-Meim)2]·2(2-Meim)}n (1) and [Cd(μ1,3-sq)(H2O)2(4(5)-Meim)2]n (2), (sq = squarate, 2-Meim = 2-methylimidazole, 4(5)-Meim = 5-methylimidazole) have been synthesized and structurally characterized by X-ray crystallography. The spectral (IR and UV–Vis) and thermal analyses are also reported. The Co(II) and Cd(II) ions are distorted octahedrally coordinated by four oxygen atoms of two O1–O3-bridging squarate ligands and two trans-aqua ligands, and by two nitrogen atoms of the trans-imidazole (2-Meim or 4(5)-Meim) ligands. The structures of 1 and 2 consist of one-dimensional chains of μ-1,3-squarato bridged metal(II) complex units. These chains are held together by hydrogen bonding interactions, forming three-dimensional framework.

Graphical abstractTwo one-dimensional coordination polymers of Co(II) and Cd(II)-squarate with 2- and 4(5)-methylimidazole ligands, {[Co(μ1,3-sq)(H2O)2(2-Meim)2]·2(2-Meim)}n (1) and [Cd(μ1,3-sq)(H2O)2(4(5)-Meim)2]n (2), have been synthesized and structurally characterized by X-ray crystallography. The Co(II) and Cd(II) ions are distorted octahedrally coordinated by four oxygen atoms of two O1–O3-bridging squarate ligands, two trans-aqua ligands and two nitrogen atoms of the trans-imidazole (2-Meim or 4(5)-Meim) ligands. The structures of 1 and 2 consist of one-dimensional chains of μ-1,3-squarato bridged metal(II) complex units. These chains are held together by hydrogen bonding interactions, forming three-dimensional framework.Figure optionsDownload full-size imageDownload as PowerPoint slide