Water-stable Cd(II) metal-organic framework as multi-responsive luminescent sensor for CrO42−, Cr2O72− ions and picric acid as well as its mixed matrix membranes

Closed-shell metal-organic frameworks have attracted much attention for their plentiful structural features and remarkable fluorescent properties. Herein, via solvothermal method, novel triphenylamine-based Cd(II) metal-organic framework, {[Cd2(TFBA)(bibp)2H2O]·DMF·2H2O}n (MOF-1) (H3TFBA ​= ​tris(3'-F-4'-carboxybiphenyl)amine, bibp ​= ​4,4'-Di(1H-imidazole-1-yl)-1,1'-biphenyl), has been successfully synthesized and fully characterized. Based on single-crystal X-ray analysis, MOF-1 crystallizes in triclinic space group P-1 and displays a three-dimensional 3D framework structure. MOF-1 presents excellent thermal stability and chemical stability in various pH aqueous solution and DMF. The luminescent sensing studies indicate that MOF-1 could rapidly detect Cr2O72−, CrO42− and picric acid (TNP) by luminescence quenching in aqueous solution with high sensitivity. Reusability and practical application as mixed matrix membranes that MOF-1 could be considered as a potential luminescent sensor for detecting pollutant ions and organic molecules. Furthermore, the possible mechanisms of its luminescent quenching process have been investigated by powder X-ray diffraction (PXRD), UV–vis spectra, luminescence titration and lifetime experiments.