Synthesis And Recognition Properties Of Coumarin And Flavone Fluorescence Chemosensors

Small molecule fluorescent compounds as chemosensors in biological and environmental fields has become a convenient and effective detection method,so the research and development of small molecule chemosensor also becomes more and more important.This thesis focuses on some important materials,which are of great significance in the field of detection,and two kinds of compounds were synthesized by simple and effective synthesis method,which were coumarin derivatives and flavone derivatives.The photophysical properties of various compounds on the detection of specific substances were investigated.The corresponding recognition effect and recognition mechanism were explored.(1)Coumarin amide compounds 1-6(2)flavonoid compounds 7-13Six coumarin amide compounds 1-6 were synthesized in the coumarin system.In the process of design,synthesis,characterization and investigation of the fluorescent chemosensors,not only six new chemosensors with specific recognition of cyanide anion were obtained but also the crystal structure of two compounds(compounds 4 and 6)were obtained.The experiment results indicate that all the six compounds can recognize cyanide anion in the organic solvent,which is not only reflected in the changes in the absorption spectra and fluorescence spectra of compounds before and after adding cyanide anions,but also in the color changes of compounds solution before and after adding cyanide anions,which can be observed by the naked eye.For example,after the addition of cyanide anions,the color of compounds 3,4 and 6 solutions can change into colorless,the fluorescence of compounds 3 and 6 in solution will be quenched and the fluorescent of compound 4 solution can become stronger.In this system,seven flavonoids derivatives 7-13 were synthesized.Based on the different chemical modification,different compounds were obtained,and they can be used to detect different substances in different conditions.The experimental results showed that compounds 7-9 in organic solvent can not only achieve selective recognition of cyanide ion but also can realize the detection and recognition of copper ions,and the recognition phenomenon can not only be observed by the changes of UV absorption spectra and fluorescence spectra but also can through the change of color and fluorescence of compounds before and after the addition of specific ions.During the study of compounds 10 and 11,it was found that these two compounds can be used to identify the specific metal ions in the buffer solution.Compound 10 can identify copper ions and zinc ions.These two ions can cause different changes of the absorption spectra of compound 10.And the addition of copper ions can make the fluorescence of compound 10 be quenched while the addition of zinc ions can make the fluorescent of compound itself increase significantly.The corresponding color and fluorescence changes of compound 10 are also visible to the naked eye.Compound 11 can only be used for the selective recognition of copper ions,and has a low absorption and fluorescence detection limit for copper ions.The design and synthesis of compounds 12 and13 are for the identification of specific amino acids.The experiment indicates that compound12 with nickel ion can occur huge changes in absorption spectra and an obvious weakening ina fluorescence spectra,and after the addition of cysteine(Cys)or homocysteine(Cys)the absorption and fluorescence occurred an obvious recovery phenomenon.For compound 13,only the addition of Cys can cause the enhancement of fluorescence intensity.Therefore,it has obvious advantages in the detection of Cys.