The Fluorescent And Phosphorescence Hg²⁺ Probes Based On Thiophen-2-yl-benzothiazole

In recent years, chemical sensors with the advantages of real-time response have attracted more and more attention. Fluorescent chemical sensors have some advantages of high sensitivity, rich signal of measurement and simple design for the prober. Compared with fluorescent chemical sensors, Iridium (Ir) based on heavy metal complexes phosphorescence chemical sensors have a long life, a large stokes displacement, and not susceptible to background interference, as well as high sensitivity. Mercury is one of the metal elements of the most threatening adverse to the body and the environment. The detection of mercury ions in the environment has caught more and more people’s attention. Therefore the design and synthesis of novel efficient fluorescent phosphorescent mercury ion microprobe is an urgent task for the chemists.First of this paper, thiophen-2-yl-benzothiazole to be nuclear, by changing the substituents (from electron-donating group to electron-withdrawing group), we synthesized a series of derivatives for the detection of mercury ions, getting fluorescent probes of OFF/ON type, ON/OFF type as well as ratiometric type, with the human eye identification function. By means of electrochemical and NMR titration analysis, we know the interaction mechanism of various substances with Hg2+.The anti-jamming of the small molecule fluorescent probes are relatively poor, so the small mol ecul e f I uorescent probes are made to Iridiurn compl exes for the detecti on to Hg22+, in order to improve the selectivity and anti-jamming. This series of complexes by near infrared light to orange red, due to the iridium complexes of ligand contaning two S atom, according to the hard and soft Acid-base theory, the joining of mercury ion will make complexes unlock or the occurrence of coordination, which led to the spectra of UV absorption and fluorescent emission to be changed.