Design,synthesis And Recognition Performance Of Probes For Metal Cations Based On Coumarin

Fluorescence probes are widely applied in the detection of metal ions owing to their advantages of high selectivity,high sensitivity,real time monitoring and simple operation.In this thesis,according to the research status and development trend on coumarin-based fluorescent probes,a series of fluorescent probes which can be used for ion detection in water environment have been designed and synthesized and their recognition mechanism were preliminary investigated.Six Hg²⁺ fluorescent probes A1-A2 and B1-B4 containing dithiocarbamate group were designed and synthesized.According to the experiment of selectivity and competition.this type of probes were found to have good recognition effect to Hg²⁺ in presence of other metal ions,Probe 2-oxo-2-（（7-diethylamino-3-coumarin）amino）diethylamino dithiocarbamate（B3）in CH3CN/HEPES（v:v = 1:1,pH = 7.4）showed a selective response to Hg²⁺ with fluorescence quenching（80.5 %）.Four dicoumarin containing fluorophores C1-C2 and D1-D2 were designed and synthesized.In CH3CN/HEPES（v:v = 1:1,pH = 7.4）buffer solution,the fluorescence quenching effect for bis(N-（3-coumarin）-2-propanedithiol diacetamide（C1）and bis(N-（7-diethylamino-3-coumarin）-2-propanedithiol diacetamide（C2）to Hg²⁺ to 88.1 % and 88.4 % were observed.Probe bis(N-（3-coumarin）-2-dimethylpropyl diamino diacetamide（D1）in CH3CN/H2O（v:v = 1:1）was sensitive and selective for Fe3+ with the fluorescence enhancement（3.9 times）and bis(N-（4-methyl-7-coumarin）-2-dimethylpropyl diamino diacetamide was sensitive to Cu²⁺ in CH3CN/HEPES（v:v = 1:1,pH = 7.4）buffer solution showing fluorescence quenching（85.2 %）.