Multifunctional luminescent Cd (II)-based metal-organic framework material for highly selective and sensitive sensing 2,4,6-trinitrophenol (TNP) and Fe3+ cation

Abstract

Two multifunctional luminescent Cd(II)-MOFs materials, namely {[Cd3(BPDPE)(BDC)3·(DMF)2]2·DMF·2H2O}n (1) and {[Cd(BPDPE)(NDC)·(H2O)]·(H2O)}n (2) (BPDPE = 4,4′-bis(pyridy)diphenyl ether, H2BDC = 1,4-benzenedicarboxylate, H2NDC = 2,6-naphthalenedicarboxylic acid), were synthesized and systematically characterized. Complex 1 possesses a 3D structure constructed by BPDPE and BDC2− linking nonlinear trinuclear secondary building units [Cd3(COO)6], while complex 2 reveals a 2D wave-like sheet assembled by BPDPE linking [Cd(NDC)]n chain, the adjacent sheets interact each other by various H-bondings. Photoluminescence measurement revealed that complex 1 exhibits stronger emission peak by comparison of organic ligands, thereby serving as a promising candidate for fluorescent sensing materials. It is surprising find that complex 1 can highly sensitive fluorescent sense 2, 4, 6-trinitrophenol (TNP) through luminescence quenching effect. In addition, complex 1 shows highly sensitive fluorescent sensing for Fe3+ cation than for other metal ions. Furthermore, the quenching mechanisms of complex 1 as multifunctional sensors have been studied.