A 3D supramolecular network as highly selective and sensitive luminescent sensor for PO 4 3− and Cu 2+ ions in aqueous media

A 2D coordination polymer, {[Zn(btca)(py) 2 ]} n ( 1 ), (H 2 btca = benzotriazole-5-carboxylic acid, py = pyridine), has been prepared with high yield by the hydrothermal reaction of H 2 btca and Zn(NO 3 ) 2 ·6H 2 O 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 Zn 2+ adopts a five-coordinated pentagonal bipyramid geometry with one O atom from one carboxylate group of btca 2− ligand and four N atoms from two btca 2− ligands and two py molecules. Adjacent Zn 2+ are connected by btca 2− 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 Cu 2+ and PO 4 3− could reach 3 and 45 ppm, respectively, suggesting that 1 can sensitively and selectively detect Cu 2+ and PO 4 3− in aqueous solution.