Syntheses, crystal structures, and properties of four coordination polymers with a new bifunctional ligand

Four new coordination polymers, {[Cd-2(L)(2)center dot H2O]center dot 4DMF.14H(2)O}(n) (1), ([Cd (L)center dot 2DMF-6H(2)O) (2), {[Zn-2(L)(2)]center dot 4DMF center dot 5H(2)O) (3) and ([Cu (L)]center dot 2DMF}(n) (4) (H2L -2,5-bis((4H-1,2,4-triazol-4-yl)carbamoyl)terephthalic acid), have been synthesized under solvothermal conditions and structurally characterized by singlecrystal X-ray diffraction. All of them exhibit three-dimensional structures possessing one-dimensional channels filled with solvent molecules. 1 is a 3D framework with large 1D channels (6.60 x 8.56 angstrom(2)) filled with free DMF molecules and the 3D structure of 1 is a new (4, 8) network with Schlafli symbol {4(16).6(12)}{4(4).6(2)}(2). 2 and 3 with different metal centers have similar structure except for the numbers of free water molecules. They both feature a (4, 4)-connected 3D network of {6(5).10) (6(5).8) topology with left- and right-handed helical chains along b-axis. While 4 is a 3D framework with typical CdSO4 topology. In addition, 1-3 show strong fluorescent emissions at room temperature, which can be assigned to the ligand-to-ligand charge transfer (LLCT) emissions. (C) 2014 Elsevier Ltd. All rights reserved.