Gas adsorption and Fluorescent Sensing Properties of Three Metal-Organic Frameworks Based on 3,5-di(2’,5’-dicarboxylphenyl)benozoic Acid and Cadmium Ions

摘要： Three 3D Cd(Ⅱ) metal-organic frameworks(MOFs), namely, {[Cd3(L)(OH)(H2O)3]n·2H2O} (1), {Cd5(L)2(H2O)9}n (2) and {Cd2(L)(bib)(NH4)}n (3), have been synthesized based on H5L and cadmium ion under hydrothermal conditions (H5L = 3,5-di(2’,5’-dicarboxylpyl)benozoic acid, bib = 1,4-bis(1-imidazoly)benzene), and characterized by IR spectrum analysis, powder X-ray diffraction analysis (PXRD) and thermogravimetric analysis (TGA). X-ray single crystal diffraction analyses showed that complex 1 is a porous 3D 4-connected net with the point symbol of {4.65} with the trinuclear [Cd3(OH)(COO)5] SBUs, complex 2 displays a 3D framework 7-connected net with the point symbol of {33.412.55.6} with the pentanuclear [Cd5(COO)10(H2O)9] SBUs and complex 3 presents a porous 3D 4,6-connected net with the point symbol of {43.610.82}{43.63}. Furthermore, fluorescent measurements indicated that 1 and 2 have potential application in the detection for Fe3+, CrO4 2- and Cr2O7 2- ions in aqueous solution. Gas sorption properties exhibited that complex 1 has better hydrogen storage performance.