Synthesis Of Reaction-based Fluorescent Probes And Their Metal Ions Recognition Properties

Small-molecule fluorescent probes play an important role in numerous fields, such as chemistry, medicine, environmental monitoring and life sciences. These probes offer powerful reagents to interrogate the physiology and pathology of reactive chemical species in their native environments with minimal perturbation to living systems. The search for selective and efficient fluorescent probes to detect various chemically and biologically pertinent species is an important area of research. Different from the conventional fluorescent probes, there are chemical bonds formed between the targets and the reaction sites of reaction-based fluorescent probes. These chemical changes can induce the change of the probes’properties such as absorption and emission, which can be used to design fluorescent probes.In this thesis, we have designed reaction-based fluorescent probes whose main chemical structure is1,3-dithiane modified BODIPY or curcumin modified with allyl ethers. Then we have synthesized two fluorescent probes for Hg2+(Ph-BODIPY-CHSS and BODIPY-Ph-CHSS) and one for Pd0(Allkyl-BF2-curcumin).In acetonitrile and water solvent system, both Ph-BODIPY-CHSS and BODIPY-Ph-CHSS can detect Hg2+well. Although the structure of the two probes are similar, they have shown different properties because of the different location of thioacetal substituents. When Hg2+was added, both of the thioacetal substituents were transferred to the aldehyde, but the fluorescent emission of the former one was enhanced while the fluorescent emission of the latter one was weakened.In the acetonitrile solution of Allyl-BF2-curcumin, the fluorescent emission of the solution was gradually quenched because of the increasing concentration of Pd2(dba)3, which can react with the allyl attached to the probe and lead to the shedding of the group. During the process, the colour of the solution had also changed, which could be identified by naked eyes.