Water-Stable Cd(Ii) M Etal-Organic Framework as Multi - Responsive Luminescent S Ensor for Cro4- , Cr2o72- Ions and Picric Acid as Well as its Mixed Matrix Membranes

Abstract

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, [Cd 2 (TFBA) 2 (bibp)H 2 O]n ( MOF-1 ) ( H 3 TFBA = tris(3’-F-4’-carboxybiphenyl)amine, bibp = 4,4 '-Di(1H-imidazol-1-yl)-1,1'-biphenyl), has been successfully synthesized and fully characterized. Based on single-crystal X-ray analysis, MOF-1 displayed interpenetrating 3D microporous structure with triclinic space group P-1 . MOF-1 presented excellent thermal stability and chemical stability in various pH aqueous solution and DMF. The luminescent sensing studies indicated that MOF-1 could rapidly detect Cr 2 O 7 2- , CrO 4 - and picric acid (TNP) by luminescence quenching in aqueous solution with high sensitivity. Reusability and practical application as mixed matrix membranes demonstrated 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.

Keywords: metal-organic frameworks, luminescent, picric acid, single-crystal X-ray analysis, TGA, mechanisms