A luminescent Cd(II)-MOF as recyclable bi-responsive sensor for detecting TNP and iron(III)/silver(I) with high selectivity and sensitivity

A new three dimensional framework ([Cd-2(BPDPE)(2)(chdc)(2)(H2O)(2)]center dot 4H(2)O)(n) (1) (BPDPE = 4,4'-bis(pyridyl)diphenyl ether H(2)chdc = 1,4-cyclohexanedicarboxylic acid) has been successfully synthesized and characterized. In this complex, the chdc(2-) adopts tran-configuration, was linked by three types of Cd ions to form wave-like 2D layer with hexagonal grids. The 2D layers are linked by meso-helical chains Cd-n(BPDPE)(n) to form a 3D framework. It is surprised find that complex 1 can highly sensitive sense 2, 4, 6-trinitrophenol (TNP) through luminescence quenching effect, the quenching constant is up to 2.794 x 10(5) M-1. In addition, complex 1 also presents highly sensitive fluorescent sensor for detecting Fe3+ and Ag+ ions. The quenching constants are 2.893 x 10(4) M-1 and 1.483 x 10(4) M-1. Furthermore, the quenching mechanisms of complex 1 as multifunctional sensor have been studied. (C) 2018 Elsevier Ltd. All rights reserved.