Synthesis And Properties Research Of Fluorescent Probes To Al³⁺ And Fe³⁺ In Aqueous Solutions

Many metal ions play important roles in the life processes. However, varietyof diseases can be induced if the concentrations of the metal ions are higher thannormal in the organism body. So how to detect and control the concentration ofmetal ions has an important significance for the life processes. The fluorescenceprobes have been widely researched and applied in the field of the metal ionsdetection due to the high sensitivity, good selectivity, low detection limit, simpleoperation, and fast response time. In this thesis, three novel and simple compoundshave been synthesized, which can be used to detect Al3+and Fe3+in aqueous solutionwith high sensitivity.Their structures were characterized by1H-NMR, mass spectrometry andelement analysis, and their optical properties, such as fluorescence spectrum andabsorption spectrum, were also studied. Compound1is almost no fluorescence inthe absence of Al3+and Fe3+. The fluorescence intensity of1, which was synthesizedbased on the coupling reaction of amine and halogenated hydrocarbon, increasedsignificantly and accompanied a clear solution color change in the presence of Al3+and Fe3+. Compound1can be applied in a wide range of pH. It presented a goodlinear relationship between the increase of the fluorescent intensity and theconcentration of the metal ions in the concentration range of0-20μmol/L, so it canbe used to realize the quantitative analysis of the Al3+and Fe3+. Al3+and Fe3+can berecognized accurately without the interference of other coexisting metal ions.Compound2was synthesized through the Wittig reaction, which is also a goodsensor for Al3+and Fe3+with high selectivity and high sensitivity. The fluorescentintensity of compound2increased3and6times, respectively, when1equivalentAl3+and Fe3+were present, and the results were not affected by other coexistingmetal ions. Al3+and Fe3+can be recognized accurately in neutral or weak acidenvironment. In order to study the recognition mechanism of compound2, a schiffbase compounds3was synthesized, in order to speculated the recognition mechanism between compound2and Al3+and Fe3+.