Study On Imine Coumarin Fluorescent Probes And Their Metal Complexes

In the past ten years,the optical sensor with simple operation method,high efficiency and high sensitivity has become one of the most important research directions in the field of supramolecular chemistry.It has a wide range of applications in the monitoring of ion content in living environment,molecular catalysis,the direction and identification of trace elements in organisms and in the determination of trace elements..Some of the coumarin compounds are derived from nature,and some are derived from artificial synthesis,so they are relatively easy to obtain.Their relative molar masses are generally small and have unusual molecular structures,while the quantum efficiency and Stokes shift of such compounds are generally large,so they are highly chemically active and very stable.Based on the above advantages,attempts to introduce various functional groups at different sites of carbon atoms on the coumarin ring,it is possible to design and synthesize derivatives with unique functions,which can be seen in various fields of life.The paper firstly summarizes the current development of imine coumarin compounds,designs and prepares four imine fluorescent probes,and tests them for fluorescent probe properties.These derivatives all contain carbon-nitrogen double bonds or phenols.Functional groups such as hydroxyl groups,so they have the possibility of coordination with transition metal ions,so that it is expected to form complexes with different molecular spatial configurations,focusing on pre-synthesized target ligands or complexes to further explore and explore the target product optics.The specific work is as follows:Firstly,the identification principle of optical sensors,as well as the properties and structure of imines and coumarin derivatives,classification,synthesis methods,research progress in the field,etc.,are introduced respectively.Part of the frontier research on probes.Secondly,a cyanide ion fluorescent probe(L~1)was synthesized and characterized by UV/Vis spectra,fluorescent spectra and nuclear magnetic titration.It was proved that the probe can be used to specifically identify cyanide ion in the dimethyl sulfoxide solution.Next,a zinc ion fluorescent probe(L~2)was synthesized and characterized by UV/Vis and fluorescence spectra.It was proved that the fluorescence intensity of the solution increased with the increase of zinc ion concentration in the dimethyl sulfoxide solution of the probe with the addition of zinc ions.Other ions do not significantly interfere with the recognition of zinc ions,and probes can be used to specifically recognize zinc ions.We also cultured the complex crystals of ligands coordinated to zinc ions and performed data analysis.Then,the performance of the sodium ion fluorescent probe(L~3)of salicylaldehyde group was studied,and the crystal of the related ligand was cultured and characterized by UV/Vis and fluorescence spectra.It was proved that the zinc ion in the dimethyl sulfoxide solution of the ligand the solution was added to the ligand solution and it was found that the fluorescence intensity of the solution did not change significantly.In the presence of zinc ions,the addition of sodium ions to the solution revealed a significant increase in fluorescence intensity,indicating that the probe specifically recognizes sodium ions in the presence of zinc ions.Finally,the synthesis and performance of the last zinc ion fluorescent probe(L~4)were studied.The UV/Vis spectra,fluorescent spectra and nuclear magnetic titration were used to characterize the solution.It was proved that in the dimethyl sulfoxide solution of the ligand,the solution was added with zinc ions.The fluorescence intensity increases.The change in fluorescence intensity is linear with the concentration of zinc ions.Other ions do not significantly interfere with the recognition of zinc ions.Probes can be used to specifically recognize zinc ions.