Synthesis And Properties Of Fluorescein Derivatives Based On Rhodamine And Rhodamine

Designand synthesis of fluorescent probe molecules with specific functions has become a hot topic in current research.Because of the low cost,rapid analysis time and obvious fluorescent dyeing of fluorescent probe technology,it has been widely used in industrial manufacturing,energy conversion,biotechnology,information science and other fileds.Fluorescein and rhodamine-based organic fluorescent probes have become the most studied fluorescent precursors due to their excellent fluorescence quantum yield,good light stability and high dyeing efficiency.In this dissertation,two rhodamine-specific"on-off"fluorescent probes R6G and RB were synthesized by splicing different groups with rhodamine as the mother nucleus;fluorescent probe R3 was synthesized using fluorescein as the mother nucleu.The main contents are summarized as follows:1.Exploration of fluorescent probe R6GA fluorescent probe R6G was synthesized,which is capable of simultaneously recognizing Al³⁺and Hg²⁺in acetonitrile and water?V:V,4:1?systems.It was found by color change that the solution turned red after adding Al³⁺and Hg²⁺,but showed orange yellow and orange red in the UV lamp.In the ion interference test,it was found that Al³⁺and Hg²⁺had mutually reinforcing effects.The detection of the two ions by the probe molecule at pH 6-7would not be substantially unaffected by pH.The absorption intensity experiment showed that the detection limit of the probe reached 1.99×10^-7mol·L^-11 when the concentration of Al³⁺was(1.0×10^-6-3.0×10^-5mol·L^-1);at the concentration of Hg²⁺was(1.0×10^-6-5.0×10^-55 mol·L^-1),the detection limit of the probe reached 1.74×10^-77 mol·L^-1.At the same time,the reversibility experiment also showed that the detection of Al³⁺by this probe was reversible,and the detection of Hg²⁺was irreversible.2.Exploration of fluorescent probe RBA novel reversible fluorescent probe RB which can selectively recognize Hg²⁺in ethanol and water?V:V,4:1?systems was synthesized.At the same time,the probe is not interfered by other ions when detecting Hg²⁺.The detection of Hg²⁺at pH 7-8 is not affected by pH.The results of the absorption intensity indicated that the detection limit of the probe reached1.42×10^-66 mol·L^-11 when the concentration of Hg²⁺was(1.0×10^-6-5.0×10^-55 mol·L^-1).The UV absorption results showed that the probe had complexation reaction with Hg²⁺,and the color of the solution changed from colorless to pink,but still pink under UV light.3.Exploration of fluorescent probe R3The design idea of R3 is to use fluorescein as the parent nucleus and obtain a novel compound with dual fluorophores by continuously react with hydrazine hydrate,terephthalaldehyde and Dpco.It was found by nuclear magnetic resonance that R3 was insoluble in chloroform,could react with DMSO,and had a poor spectrum in acetonitrile and methanol.The watch needle was made by infrared test.And the response test to metal ions also found that R3 does not have the ability to recognize common metal ions.