Multi-responsive Luminescent Probe with Bis-imidazolyl Biphenyl and Aromatic Polycarboxylic Acids Ligands for Sensing Fe3+, Cr2O72- and CrO42- in Aqueous Solution

One zinc-based metal organic framework (MOF): [Zn(LBIX)(HEA)](n) (1) was synthesized by hydrothermal synthesis with 4,4 '-bis((1H-imidazol-1-yl)methyl)-1,1 '-biphenyl (LBIX) and 1,2-phenylenediacetic acid (H(2)HEA) as ligands. The structure was characterized by single-crystal X-ray diffraction analysis, elemental analysis, infrared spectroscopy and thermogravimetric analysis. The single crystal structure analysis shows that the complex extends along three directions of a, b and c, forming a three-dimensional structure. Experiments related to fluorescence show that the complex 1 has good fluorescence performance in aqueous solution and can be utilized to quickly identify Fe3+, CrO42- and Cr2O72- ions (K-sv quenching efficiency for Fe3+:1.71x10(4) M-1, CrO42-:1.07x10(4) M-1 and Cr2O72-:1.15x10(4) M-1) and low detection limits (Fe3+:1.52 mu M, CrO42-:1.53 mu M and Cr2O72-:1.70 mu M).