One-dimensional coordination polymers based on a new 3-position substituted imidazo[1,2-a]pyridine ligand: Crystal structures, photoluminescent and magnetic properties

A new 3-position substituted imidazo[1,2-a]pyridine ligand. namely, 5-(2-chloroimidazo[1,2-alpyridine-3-carboxamido) isophthalic acid (H2L) was synthesized and characterized by H-1 NMR spectroscopy. Based on this ligand, three isostructural one-dimensional coordination polymers, [ML(H2O)(2)](n) (M = Zn (1), Ni (2) and Co (3)) were synthesized under the solvothermal conditions, and structurally characterized by single crystal X-ray diffraction, infrared spectroscopy, powder X-ray diffraction and elemental analyses. The coordination polymer 1 reveals similar photoluminescent spectrum to H2L ligand, but possesses the enhanced phosphorescent emission and higher phosphorescent quantum yield, compared to H2L ligand. Furthermore, the magnetic properties of coordination polymers 2 and 3 have been investigated, the results show there are antiferromagnetic interactions between the Ni-II ions or Co-II ions in 2 or 3. (C) 2018 Elsevier Ltd. All rights reserved.