Synthesis And Properties Of Benzo-1,3-azole Heterocyclic Fluorescent Compounds

In recent years, potential sensitivity probe compounds were widely studied. And thiskind of compounds had very important significance in biological membrane potentialdetection. Due to their advantages, including short reaction time, good water solubility, highermolar absorption coefficient, avoiding the background interference and high detectionsensitivity, these compounds got a lot of attention and also gradually became one of theinvestigative focuses. This kind of compounds has special π-conjugated systems which issimilar to cyanine compounds. And this distinctive structure may make these compounds havegood fluorescence properties.In this paper, a series of potential sensitivity probe compounds and their derivatives weresynthesized from2-methylbenzothiazole as a matrix, triethyl orthoformate and rhodanine-3-acetic acid. The structures of all the target compounds were characterized by1H-NMR, IRand MS.According to the structural features of this kind of compounds, we can find that thesecompounds not only have good water solubility, but also can coordinate with metal ions inspecific solution. So this kind of compounds has the possibility to detect the metal ions asfluorescence probe compounds through the coordination function. In view of this inference,the UV-Vis and the fluorescence properties of these compounds were also taken in this paper.From the determination of the influence of14kinds of metal ions on the fluorescenceintensity of the target compounds in methanol solution and aqueous solution, we found thatSn2+had a very good fluorescence quenching effect on compounds C, D, G and H. Theemission wavelength of these four compounds is around579nm which can effectively avoidthe biological fluorescence interference and improve the SNR (signal to noise ratio); goodwater solubility can reduce the self-aggregation of these compounds in water in order to getgood fluorescence intensity of these compounds in water. Therefore, this series of compoundscan be used as the Sn2+fluorescence probe sensor for a further study.Due to the introduction of rhodanine-3-acetic acid, the water solubility of the compoundsmentioned above improved obviously. According to the property above and the compoundsprevious studied in our laboratory, a series of compounds with good solubility, strongfluorescence intensity and red-shift excitation wavelength were synthesized from2-(1H-benzo[d]imidazol-2-yl)phenol as the basic structure. The determination of thefluorescence alteration of the target compounds affected with14kinds of metal ions abovewas taken. From the detection result we found that the compound I had certain selectivity toCo2+and compound J had certain selectivity to Fe3+. Therefore, this series of compounds canbe used as their corresponding metal ions fluorescence probe sensor for a further study.