Hydrothermal syntheses, crystal structures and luminescence properties of Cd(II) coordination polymers based on 2-(pyridine-2-yl)-1H-imidazole-4,5-dicarboxylic acid

Two new supramolecular compounds, [Cd(H2PIDC)2(H2O)]·H2O (1) and {[Cd(H2PIDC)2(H2O)]·2H2O}n (2) (H3PIDC = 2-(pyridine-2-yl)-1H-imidazole-4,5-dicarboxylic acid), have been synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction. Compound 1 contains discrete mononuclear structure, and compound 2 consists of one-dimensional left- and right-helix chains. Both are constructed into high-dimensional supramolecular frameworks by strong non-covalent hydrogen bonding and π⋯π stacking interactions. In addition, they were characterized by IR and elemental analysis, and their fluorescence properties in the solid state at room temperature have also been investigated.