A hydrolytically stable Zn(II) coordination polymer based on a new imidazolyl-pyrazolyl heterotopic ligand as a scavenger of MnO4− and a luminescent sensor for MnO4− and Cr2O72−

Abstract

Reactions of Zn(NO3)2 with a new rigid tripodal imidazolyl-pyrazolyl heterotopic ligand, 4-(3,5-di-imidazol-1-yl-phenyl)-1H-pyrazole (HDIPP), result in a new compound with the formula {[Zn(HDIPP)2]·2NO3}n (Zn-HDIPP). Zn-HDIPP exhibits a 3D framework with a three-fold interpenetrating dia network topology. It shows high hydrolytic stability in the pH range 3 to 11. In addition, Zn-HDIPP displays useful properties including (i) the removal of MnO4− from water with a capacity of 550 mg/g and with high selectivity when other anions are also present and (ii) the luminescence quenching detection of MnO4− and Cr2O72− in water via energy-transfer and competitive absorption mechanisms. These results show that Zn-HDIPP has the potential to be used in detection and removal of pollutants in water.