Three new luminescent cd(II) coordination polymers constructed from 2-mercaptobenzimidazole and different auxiliary ligands

Abstract

The solvothermal reactions of 2-S-HBim and Cd(NO3)2·4H2O in combination with H2ip, or 3-Hpyc or 4-Hpyc afforded three new coordination polymers, namely [Cd(ip)(2-S-HBim)2] n ·n(H2O) (1), [Cd(3-pyc)2(2-S-HBim)] n ·n(H2O) (2), and [Cd(4-pyc)(2-S-HBim)(Br)(H2O)] n (3) (2-S-HBim = 2-mercaptobenzimidazole, H2ip = isophthalic acid, 3-Hpyc = nicotinic acid, 4-Hpyc = isonicotinic acid). X-ray diffraction analyses revealed that compound 1 features a 1D infinite chain structure, which was further hydrogen-bonded into a 3D supramolecular framework. Compound 2 features a 2D layered structure with 4-connected sql plane topology, which further stacked into a 3D supramolecular framework. Compound 3 also shows a 1D infinite chain structure with dinuclear [Cd2(μ 2-H2O)2] subunits, which was further connected into a 3D supramolecular via intermolecular hydrogen bonds. Furthermore, the thermal stabilities and photoluminescent properties of 1–3 have been investigated.