The Synthesis Of Multidentate Fluorescent Reagents Based On Indole And The Recognition For Heavy Metal Ions

With the development of industry and society, heavy metals are widely used in industrial processes and social productions. Increasingly serious environmental pollution is attendant. Since heavy metals are not biodegradable, they have serious influence on the environment and living organisms. Therefore designing analytical techniques of heavy metal ions is of great importance. The traditional methods of detecting metal ions include atomic absorption spectrometry, atomic emission spectrometry, ultraviolet spectrophotometry, atomic fluorescence spectrophotometry, inductively coupled plasma mass spectrometry and the like. The atomic fluorescence spectrophotometry drew the attentions of researchers because of its high sensitivity and simple operation among these detection methods.Nitrogen heterocyclic compounds with indole skeletons are good metal complexes ligands. Due to the lone pair electrons of nitrogen atom, it is easy to incorporate with metal ions, so as to achieve the purpose of the metal ions detection. In this paper, three new indole fluorescent recognition agents were designed and synthesized respectively for the detection of the mercury ion, iron ion and cadmium ion. The following aspects were included in my work.In chapter 1, some of the developments on the detection of heavy metal especially fluorescence recognition were summarized.In chapter 2, a new type of fluorescence recognition reagent was designed and synthesized based on 2-methyl indole under mild conditions, through electrophilic substitution, nucleophilic substitution and the click reaction. Meanwhile its fluorescence spectrum properties and the selective recognition of various metal ions were explored. Finally I found it was a good detector for mercury ion.In chapter 3, long chain ether was introduced to the synthesis of another kind of new fluorescent recognition reagent. Compared with other metal ions, the study of the fluorescence spectrum was carried out. The detection of iron ion was completed.In chapter 4, a new kind of crown ether like cadmium ion fluorescent recognition reagent was designed and synthesized, introducing two molecules of indole and two molecules of long chain ether, via the click reaction of terminal alkynes and nitrogen heterocyclic compounds. Its ion selective, the scope of its quantitative analysis and the optimum testing conditions for cadmium ion detection, including temperature and time, were explored. The cadmium ion fluorescent recognition reagent had the advantages of good selectivity and high sensitivity. Potential application value in terms of environmental detection was revealed.