3D Cadmium(II)-Based Coordination Polymer Constructed from V-Shaped Semirigid Ligand: Selective Detection of Oxoanion Pollutants CrO42-, Cr2O72-, MnO4- in Water

A new coordination polymer (CP), namely, [Cd(HL)(4,4 '-bipy)] (1) (H3L = 4-(5-carboxy-pyridine-3-yloxy)-phthalic acid, 4,4 '-bipy = 4,4 '-bipyridine), was synthesized employing a V-shaped asymmetric tricarboxylic acid ligand under hydrothermal condition. Single-crystal X-ray diffraction analysis indicates that compound 1 exhibits a novel three-dimensional (3D) framework with (3, 5)-connected (6(3))(6(9)center dot 8) topology. Meanwhile, it shows high selectivity and sensitivity for oxoanion pollutants CrO42-, Cr2O72-, and MnO4- anions in aqueous solutions with detection limits of 4.12 x 10(-6) M, 1.75 x 10(-6) M, and 6.47 x 10(-7) M, respectively. The high selectivity and low detection limit indicate that the compound is promising functional luminescence probe for CrO42-, Cr2O72-, and MnO4-. The mechanisms of the quenching effect and sensing properties were discussed in detail.