Series of 2D and 3D Coordination Polymers Based on 1,2,3,4-Benzenetetracarboxylate and N-Donor Ligands: Synthesis, Topological Structures, and Photoluminescent Properties

Nine new coordination polymers, namely, [Mn2(L)(H2O)4]·H2O (1), [Cd(L)0.5(H2O)] (2), [Zn5(L)2(μ3-O)2(H2O)4]·2H2O (3), [Zn4(L)2(μ3-O)2][Zn(H2O)5]·2H2O (4), [Zn2(L)(biim-4)0.5(H2O)3]·H2O (5), [Cd2(L)(bpy)(H2O)]·2H2O·0.5(CH3CH2OH) (6), [Cu2(H2L)2(bpy)2] (7), [Cu2(L)(bpy)(H2O)] (8), and [Cu2(L)(bpy)1.5(H2O)2.5] (9), where H4L = 1,2,3,4-benzenetetracarboxylic acid, biim-4 = 1,1′-(1,4-butanediyl)bis(imidazole), and bpy = 4,4′-bipyridine, have been synthesized under hydrothermal conditions. Compound 1 displays a rare trinodal (3,4,7)-connected (42·6)(45·6)(47·68·86) topology. 2 possesses an α-Po net. 3 is a novel 3D framework based on pentanuclear ZnII clusters. By adjustment of the pH values of the reaction mixture of 3 with a Na2CO3 solution, a structurally different compound, 4, was obtained, which exhibits a 3D porous framework with the [Zn(H2O)6]2+ cations located in the channels. 5 is an unusual example of a trinodal (3,5)-connected network with a Schläfli symbol of (42·6)(62·8)(42·62·85·10), whereas 6, containing tetranuclear CdII clusters, shows a rare (4,6)-connected (44·62)2(44·610·8) topology. 7 exhibits a unique polythreading network, while 8 displays a scarce trinodal (3,4,5)-connected self-penetrating network. In comparison with 8, the chiral compound 9 possesses an unprecedented tetranodal (2,4)-connected (7)(75·11)(62·73·8)2(6·74·10)2 topology. The effects of the carboxylate ligands, the pH values, the reaction temperatures, the central metals, and the neutral ligands were elucidated. The IR spectra, thermogravimetric analysis, and luminescent properties for the compounds were also investigated.