Synthesis And Properties Study Of 2, 4-Diphenylquinoline Derivatives

In recent years, since the abuse of heavy meatl that mercury pollution has threatened the environment and people's life. It's important to develop new strategies of detecting such toxic meals. Fluorescent probes can transfer molecular recognition events into fluorescence signals, which make a bridge between the molecular analyses and the analyst as an observer. The advantages of fluorescent probes include accurate,on-line,low-cost,high sensitivity and good selectivity. Therefore, fluorescent molecular probes play an vital role in the recognition the metal ions.The fluorescence intensities of common probes (both fluorescence quenching and fluorescence enhancement) are influenced by experimental factors. The ratiometric probes can normalize the variation of these effects. The advantages are increased the range of dynamic response by changes in the intensity ratio, and establish an internal standard, thus greatly weakening the interference of other factors. But until now, the ratiometric probes are rare.2,4-diphenylquinoline are attractive fluoroionophore owing to their good photophysical properties with light, heat stability, large stokes shifts and relatively steady emission wavelengths. In this paper, we design and synthesis of six new 2, 4-diphenylquinoline derivatives DPQ-1,DPQ-2,DPQ-3,DPQ-4,DPQ-5 and DPQ-6, podand compounds OPQ-1 and OPQ-2. They are all charactered by FT-IR, Tof-ms and NMR. In a preliminary experiment, the probe DPQ-1 shows unique selectivity and high sensitivity towards Hg2+. Addition of Hg2+ gave a significant enhanced fluorescence at about 393nm and signiticant quenching fluorescence at about 465nm. It can detect Hg2+ ratiometrically without disturbed by other combining metal ions, the presence of Hg2+ induces the formation of a 2:1 metal-ligand complex, binding constants is 8.2×108 M-1, the detection limit of the probe was determined to be 1.8×10-6 mol/L. To further experiment with Tof-ms, upon addition Hg2+, Hg2+ -promoted intromolecular guanylation of DPQ-1, lose HgS.Meanwhile, we take the same method to test the properties of DPQ-4, the reaserch results are that DPQ-4 has a better response to Cu2+ and Zn2+ that can be used to detect Zn2+ and Cu2+. Moreover DPQ-4·Cu2+ complexes can be used to detection of P2O72- and HPO4- which can be served as molecular fluorescence sensor for P2O72- and HPO4-, because of the good solubility of DPQ-4, it has expected to be widespread used for ion recognition.