Syntheses, Structures, and Photoluminescences of Four Cd(II) Coordination Architectures Based on 1-(4-Pyridylmethyl)-2-methylimidazole and Aromatic Carboxylates: From One-Dimensional Chain to Three-Dimensional Coordination Architecture

The use of 1-(4-pyridylmethyl)-2-methylimidazole (pmmid) combined with four kinds of benzenecarboxylic acid ligands has allowed the rational design of four novel Cd­(II) coordination polymers (CPs), {[Cd­(pmmid)­(pa)­(H2O)]·H2O}n (1), [Cd2(pmmid)2(cba)4] (2), [Cd1.5(pmmid)­(tbba)3]n (3), and {[Cd­(pmmid)­(pma)0.5(H2O)]·5H2O}n (4), [H2pa = phthalic acid, Hcba = 4-chlorobenzoic acid, Htbba = 4-tert-butylbenzoic acid, and H4pma = pyromellitic acid], which were synthesized by reactions of Cd­(OAc)2·2H2O and pmmid with aromatic acid under the ammoniacal condition and characterized by elemental analysis, infrared (IR) spectroscopy, powder X-ray diffraction (PXRD), and single crystal X-ray diffraction. Complex 1 possesses a one-dimensional (1D) chain architecture, complex 2 is an interesting 1D structure containing two kinds of 1D chains, complex 3 features a two-dimensional 63 topological network structure, and complex 4 is a novel three-dimensional coordination architecture framework containing a T4(2)­10(2) water tape. In these complexes, the pmmid ligand takes a bidentate μ2-η1:η1 coordination mode, and the four benzenecarboxylate ligands are able to link Cd­(II) ions in various coordination modes, giving these Cd­(II) complexes with different structures. In addition, complexes 1–4 exhibit luminescence in the solid state at room temperature.