Preliminary Study On Synthesis And Fluorescent Properties Of(E)-2-[2-(4-Vinyloxyphenyl)Vinyl]Quinoline

The transition metal elements exist widely in the nature of human life. Some of these metal elements play important roles in the process of organism metabolism, but some are very toxic and dangerous. It is believed that Hg2+ can combine with some groups of proteins and disturb the normal metabolism due to the change of proteins’ activity. So it is necessary to detect the content of Hg2+ in the organism and the environment.Compared with the other detection techniques, fluorescence detection technology has the advantages of simple operation,high sensitivity and good selectivity for metal ions detection. Because of its observation in situ, it could be applied in dynamic imaging of the metal ions and the online analysis of the sample in vitro and in vivo.Because of the large conjugation system, phenylvinylquinoline shows good planar and fluorescent properties, which are significant affected by the substituents. This indicates it could be used as a very good fluorophore. Here we designed and synthesized a probe 3 by combining the vinyloxy unit to phenylvinylquinoline. Then fluorescent properties of probe 3 were investigated.Upon addition of 0.5 equiv Hg2+, the vinyloxy unit of fluorescence probe 3(1×10-5 M) in(CH3CN/HEPES(0.02 M, pH=7.0) = 1/1)was transferred into the corresponding phenolic hydroxyl, resulting in a red shift from 340 to 402 nm in ultraviolet absorption spectrum accompanied by the color change from colorless to pale yellow, and a red shift from 419 to 521 nm in fluorescence spectra accompanied by a marked fluorescence change from blue to yellow.The detection process can be completed within 3 minutes according to a reaction ratio of probe/Hg2+(2:1). The reaction product was separated and characterized by 1H NMR to testify its recognition mechanism.Probe 3(1×10-5 M) could at least detected Hg2+ ion at a concentration of 1×10-7 M. The probe exhibited good water solubility and a wide-range of pH value. It is believed to be a good ‘reactive’ ratiometric fluorescent probe for detection of Hg2+ ion.