Novel zinc(II) coordination polymers (CPs) based on flexible aliphatic carboxylic acids and an N-donor ligand for fluorescence sensors

Abstract

Two novel zinc (II) coordination polymers based on flexible aliphatic carboxylate ligands, succinate, and citrate, with 1,2-di(4-pyridyl)ethylene (dpe), namely, [Zn(succinate)(dpe)]0.1.5H2O (1), and [Zn2(citrate)(formate)(H2O)(dpe)].2H2O (2) were synthesized by the appropriate methods. The crystal structures were determined by single crystal X-ray diffraction. The coordination spheres around the Zn2+ ions in (1) and (2) were tetrahedral and trigonal bipyramidal, respectively. The fluorescence properties of the compounds showed emission bands at 362 and 369 nm (λex = 280 nm) for 1 and 2, respectively. Both compounds were used as nitroaromatic explosive and metal ion sensors. They selectively sensed 2,4-dinitrophenol and Fe(III) ions based on fluorescence quenching effects.