The Synthesis And Application Of Fluorescent Probes Based On Chiral BINOL

In recent years,fluorescent probes with the advantages of high sensitivity,short response time,good selectivity and convenient operation have been attracted the attention of researchers.Among many recognition applications,the enantiomeric selective recognition of chiral molecules has become a new direction in fluorescent probe research.Among them,the C₂-axis chiral binaphthol is commonly used in the design and synthesis of ion recognition and molecular enantiomeric selective fluorescent sensors due to its unique steric rigidity,multiple modification sites,stable chemistry,and good fluorescence properties.Therefore,in this paper,a series of novel fluorescent probes M1-M7 were designed and synthesized based on the chiral binaphthyl phenol structure with the introduction of nitrogen-containing heteroatomic groups（imidazolyl,pyridinyl,quinolinyl）,and the fluorescence recognition of the probes in ionic and chiral molecules was investigated to achieve selective recognition of enantiomeric isomers of chiral molecules.The main contents are as follows:In Chapter 1.The composition,recognition mechanism and classification of chemical fluorescent probes are introduced;the probes for detecting ions and the research applications of chiral binaphthyl phenols and derivatives on fluorescent probes in recent years are outlined,based on which the design ideas of this project are presented.In Chapter 2.Firstly,two bisdinaphthol fluorescent probes M1 and M2connected by biimidazole were designed and synthesized,and it was found that:M1had selective recognition of sulfate anions(HSO₃^-,SO₄^2-,SO₃^2-,HSO₄^-,S₂O₃^2-);M2produced significant fluorescence enhancement for D-2-aminobutyric acid,while it produced weaker fluorescence enhancement for L-2-aminobutyric acid,and the enantioselective The fluorescence enhancement ratio（ef）can reach 9.6,it shows that M2 has a better enantiomeric selection for the recognition of 2-aminobutyric acid and can be used to detect the ee value of amino acid samples.Then,two imidazolidinyl long-chain modified binaphthol fluorescent probes M3 and M4,which are enantiomeric to each other,were designed and synthesized.It was found that both M3and M4 had selective recognition of H₂PO₄^-in the acetonitrile system;in the CH₃CN:CH₃OH（1:49）system,both M4 and M3 had high sensitivity and specific selective recognition of S₂O₃^2-with good anti-interference ability.In Chapter 3.Firstly,a Schiff base fluorescent probe（M5）was synthesized based on R-3-formyl-2,2-binaphthol with 3-aminopyridine,and it was shown that M5has selective recognition of Sn²⁺but poor anti-interference performance in the CH₃CN:CH₃OH（1:49）system;it was also found that M5 has enantiomeric selective recognition for both 1,2-cyclohexanediamine and 2-aminobutyric acid.The8-hydroxyquinoline moiety was then introduced to participate in the recognition site modification to synthesize the biphenol fluorescent probes M6 and M7.The results showed that the cation fluorescent probe M6,synthesized with a single8-hydroxyquinoline group,had poor recognition effect except for tryptophan,while the probe M7,containing multiple synergistic recognition ligands,could specifically recognize both Cd²⁺and Zn²⁺cations.In addition,Optimization and improvement of the synthesis of the M7 intermediate azide（S-6）:the reaction of alcohol groups with DPPA under alkaline conditions of DBU to obtain bis（dinaphthol）azides.