TWO 3D Cd (II) luminescent coordination polymers as highly selective and sensitive sensing for Fe3+ and CrO42−/Cr2O72− ions in aqueous system

Abstract

Two 3D Cd (II) luminescent coordination polymers (LCPs), namely, {[Cd(bimb)Cl2]·1.5H2O}n (1) and {[Cd1.5(bbib)2.5Cl2]·3H2O·NO3}n (2) { bimb ​= ​1,3-Bis (imidazol-1-ylmethyl) benzene, bbib ​= ​1,4-bis (benzoimidazo-1-ly) benzene } have been obtained under solvothermal conditions The structural analysis of LCPs exhibited that they are 3D frameworks with (4,6)-connected dia network for 1 and (4,5)-connected tck topology network for 2. The solid state fluorescence of ligands and LCPs, and luminescent sensing experiments of LCPs for anions and cations in aqueous solutions were systematically studied. Compared with the free bimb and bbib ligands, the emission peaks of 1 and 2 are slightly red-shifted, which can be assigned to the effect of coordination. Furthermore, the fluorescence experiments indicated that LCPs 1 and 2 have high sensing sensitivity and selectivity toward Fe3+ and CrO42−/Cr2O72− ions in water system.