Imidazole-Containing Ligands Assisted Self Assembly of Two New Cd(II) Coordination Polymers: Syntheses, Crystal Structures and Photoluminescent Properties

Two new coordination polymers, {[Cd2(PDC)2(H2O)2(L1)]·2H2O}n (1) and {[Cd (2,5-PDC)(H2O)(L2)]·H2O}n (2), have been obtained from hydrothermal reactions of Cd2+ ion with the 2,5-pyridinedicarboxylic acid (H2PDC) and two imidazole-containing ligands [L1 = 1,4-bis(imidazol-1-yl)benzene and L2 = 1,4-bis(1-imidazol-yl)-2,5-dimethylbenzene]. Complex 1 features a three-dimensional 6-connected rob topological net. Complex 2 shows a two-dimensional 6-connected hxl topological net. The structural differences between 1 and 2 demonstrate that the different imidazole-containing ligands play critical roles in the formation of the resulting frameworks. The photoluminescent properties of 1 and 2 have also been investigated.