Two new luminescent ternary Cd(II)-MOFs by regulation of aromatic dicarboxylate ligands used as efficient dual-responsive sensors for toxic metal ions in water

摘要

Two new Cd(lI) metal-organic frameworks (MOFs) formulated as [Cd(L)(atpa)](n) (1) and [Cd(L)(tbta) (H2O)](n) (2) [H(2)atpa = 2-aminoterephthalic acid, H(2)tbta = tetrabromoterephthalic acid, L = 1,4-bis(benz-imidazol-1-yl)-2-butene] were hydrothermally synthesized. 1-2 were characterized by IR spectroscopy, elemental analysis, and single-crystal X- ray diffraction. 1 displays a 3D framework with five-fold interpenetrating dia topology. 2 holds a 2D corrugated sql layer. Both MOFs were confirmed to be dual-responsive luminescent sensors (Cu2+ and Cr2O72- for 1, Hg2+ and Cr2O72- for 2) in water through the luminescence quenching experiments. The detection limits for these species were 1.2 mu M (Cu2+) and 0.29 mu M (Cr2O72-) of 1, 0.043 mu M (Hg2+) and 0.13 mu M (Cr2O72-) of 2, respectively. The luminescence quenching mechanism was investigated. (C) 2018 Elsevier Ltd. All rights reserved.