A 3D supramolecular network as highly selective and sensitive luminescent sensor for PO43− and Cu2+ ions in aqueous media

Abstract

A 2D coordination polymer, {[Zn(btca)(py)2]}n (1), (H2btca = benzotriazole-5-carboxylic acid, py = pyridine), has been prepared with high yield by the hydrothermal reaction of H2btca and Zn(NO3)2·6H2O in the presence of py, which has been further characterized by kinds of methods combining elemental analysis, thermogravimetric (TG) analysis, infrared (IR) spectrum, powder X-ray diffraction (PXRD), and X-ray single-crystal diffraction. In 1, each Zn2+ adopts a five-coordinated pentagonal bipyramid geometry with one O atom from one carboxylate group of btca2− ligand and four N atoms from two btca2− ligands and two py molecules. Adjacent Zn2+ are connected by btca2− ligands to generate a 2D layer with the ‘fes’-type topology, which could further form a 3D supramolecular network through hydrogen bonds interactions. Furthermore, the luminescent results reveal that the detection limit of 1 as a luminescent sensor to probe Cu2+ and PO43− could reach 3 and 45 ppm, respectively, suggesting that 1 can sensitively and selectively detect Cu2+ and PO43− in aqueous solution.