Preparation and characterization of two novel three-dimensional supramolecular networks with blue photoluminescence

Two novel photoluminescent coordination polymers of formula [Cd(atpt)(H2O)2] · 2H2O (1) and [Zn(atpt)(H2O)2] (2) (H2atpt = 2-aminoterephthalic acid), in which the amino group of the atpt ligand coordinates to the metal(II) ions for the first time, have been synthesized through the self-assemblies of H2atpt and N-containing ligands [nicotiamide for 1 and imidazole for 2, respectively] with the metal(II) ions in the presence of NaOH. These complexes were characterized by FT-IR spectroscopy, thermogravimetric analysis (TG), elemental analysis and X-ray analysis. X-ray crystallographic studies of the complexes reveal that complex 1 is a double stranded one-dimensional chain, which further assembles into a three-dimensional supramolecular network via the interchain π–π stacking interaction and strong hydrogen bonds, while complex 2 exhibits a two-dimensional porous architecture. The extensively strong hydrogen bonds in complex 2 lead to the formation of three-dimensional supramolecular framework. Photoluminescence properties of the compounds 1 and 2 have been examined in solid state at room temperature. These compounds have been found to exhibit blue photoluminescence and may be good candidates for photoactive materials.