The Design,Synthesis And Fluorescence Properties Of Boron Compounds With Imidazole Ring Based On BINOL Core

Molecular recognition is one of the hottest research directions in the field of chemistry and life science.It is of great significance for understanding the operation process of life activities,studying the occurrence and treatment of diseases,environmental detection,and so on.Fluorescent probe has become the most important means of molecular recognition because of its hi gh sensitivity,good selectivity,simple operation,rapid detection,and so on.Herein,we designed and synthesized two boron compounds with imidazole ring and large conjugated structure based on BINOL skeleton.And further prepared the fluorescence probe for selective response to mercapto amino acids.The main contents of this paper are as follows:In the first chapter,we introduced the structure and main recognition mechanism of fluorescent probe,the application of boron atom in molecular design of fluorescent probe,the development of BINOL-based fluorescent probe in the field of molecular chiral recognition and the general situation of reactive probe for biothiols.In the second chapter,two ligands and their boron compounds were synthesized from BINOL aldehydes,and characterized by UV-Vis absorption and fluorescence emission spectra.Combined with theoretical calculation,the effects of conjugated structure and boron atom coordination on the fluorescence properties of BINOL derivatives were analyzed.The results show that boron compounds have excellent fluorescence properties and high fluorescence quantum yield s.In the third chapter,the fluorescence probes S₁ and S₂ were prepared by introducing 2,4-dinitrobenzenesulfonyl group based on boron compound s.Through the fluorescence spectra,it was found that in the solvent system of DMSO-PBS buffer(v/v=85:15),the probe S₁ can be used for rapid recognition of mercapto amino acids(the fluorescence is enhanced by 20times 30s after Cys was added,and the reaction rate constant is 0.021s^?1).The probe S₂ only responds quickly to Cys,and the detection limit is as low as 0.16?M.So it has good selectivity.After the addition of Cys to the solution of probes,the corresponding fluorescence quantum yield increased66 times and 150 times for S₁ and S₂,respectively.The study on the mechanism showed that the fluorescence intensities of the probe s were quenched due to the ICT process.After the reaction with Cys,the 2,4-dinitrobenzenesulfonyl group was removed by the sulfhydryl nucleophilic attack.Furthermore,the ICT process disappeared and the fluorescence was released.