Synthesis And Application Of Triphenylamine Chalcone And Pyrazoline

As a means of analysis and detection,fluorescent probes have important applications in life sciences and other fields because of their high sensitivity and good selectivity.Triphenylamine is a symmetrical molecule with a star structure,with stable chemical properties,easy modification of the molecular structure,and high hole transport rate.Some heteroatom compounds,such as coumarin,pyrazoline,etc.,have excellent fluorescence properties.Based on the application of molecules with chalcone structures in the field of optics,this article designs and synthesizes two molecules with chalcone structures to study their photophysical and electrochemical properties.And using chalcone molecules as reactants,pyrazoline compounds were synthesized through ring closure reaction.Combining the advantages of triphenylamine,coumarin and pyrazoline,a new type of pyrazoline metal ion fluorescent probe was synthesized.The specific content is as follows:（1）The concept,composition and mechanism of fluorescent probes are summarized,the composition and application of pyrazoline are summarized,and the research progress of triphenylamine derivates and pyrazoline metal ion fluorescent probes are also introduced.（2）Two molecules 1 and 2 based on the chalcone structure of triphenylamine were synthesized.The aldol condensation reaction of 4-diphenylaminobenzaldehyde and2-hydroxyacetophenone produces chalcone.Its molecular structure was confirmed by ¹H NMR,¹³C NMR and ESI-MS.The results of ultraviolet-visible absorption spectroscopy and fluorescence emission spectroscopy showed that the Stokes of compound 1 and compound 2in different solvents showed a linear change trend with the increase of the solvent orientation polarizability.Compound 1 and compound 2 have good aggregation-induced emission behavior in ethanol/water mixtures.Through solid-state fluorescence testing and density functional theory calculations,the emission behavior of the compound in the solid state was described.The cyclic voltammetry test shows that the reaction of the compound on the electrode was an irreversible redox reaction.（3）Synthesis of three triphenylamine pyrazoline metal ion fluorescent probes.The aldol condensation reaction of 4-diphenylaminobenzaldehyde and 2-hydroxyacetophenone produces chalcone,and the final pyrazoline T1 was produced after a one-step ring closure reaction.The synthesis of T2 and T3 were respectively synthesized from the chalcone in chapter 2 through the ring closure reaction.The structures of all final products were confirmed by ¹H NMR,¹³C NMR and MS.The optical properties of T1,T2 and T3 were studied by ultraviolet-visible absorption and fluorescence emission spectroscopy.The research results show that in the buffer solution of THF/H₂O（V/V=9:1,HEPES,10 m M,p H=7.4）,T1,T2 and T3 have fluorescence quenching responses to Fe³⁺and Cu²⁺.From the results of Benesi-Hildebrand equation and Job’s plot curve,it can be seen that T1,T2 and T3 were 1:1 coordination with Fe³⁺and Cu²⁺,and the structure of the three probes before and after the ion binding was optimized by density functional theory calculation.The electrochemical properties of the compound were studied by cyclic voltammetry.（4）A new type of coumarin-based pyrazoline Fe³⁺fluorescent probe was synthesized.After four steps of reaction,probe A was obtained.The structure of probe A was confirmed by ¹H NMR,¹³C NMR,and ESI-MS.Fluorescence spectrum test showed that probe A has a high selectivity to Fe³⁺in THF solution.Cytotoxicity and imaging tests show that probe A has low toxicity and good membrane permeability,and has been successfully applied to the detection of Fe³⁺in HeLa cells.