Synthesis And Properties Study Of Fluorescent Dyes Based On Coumarin,BODIPY And Spiropyran

Fluorescent chemosensors have been widely used for the recognition and detection of metal cations and anions as well as pH due to their high selectivity,sensitivity and lower cost.In this paper,coumarin,BODIPY and rhodamine were used as fluorescent groups to synthesize new fluorescent chemosensors,and several new fluorescent chemosensors were synthesized by introducing different structural recognition groups for structural modification,and their performances were investigated by UV-Vis/fluorescence spectrophotometry.The main research contains the following aspects:（1）A novel fluorescent chemosensor CD was synthesized by using coumarin as a fluorescent moiety and introducing a three-dimensional dendritic small molecule structure as a recognition moiety,which was structurally characterized by ¹H NMR,¹³C NMR and HR-MS.The sensor CD showed a fluorescence burst response to Cu²⁺in CH₃CN/HEPES buffer medium with a burst efficiency as high as 99.8%;the complex CD-Cu²⁺showed an obvious fluorescence enhancement response to PPi with an enhancement rate of 88%.The obvious color change of the test solution indicates that the sensor CD can achieve the purpose of continuous recognition and detection of Cu²⁺and PPi by naked eye.（2）The fluorescent chemosensor CD with 3D dendritic small molecule structure as the recognition group exists problems such as poor solubility,in this chapter,by introducing the small molecule pyridoquinoline structure into coumarin,the water content percentage in the fluorescent molecule test solvent was increased,and a novel fluorescent chemosensor CDP was synthesized,and structurally characterized by ¹H NMR,¹³C NMR,and HR-MS.The fluorescent chemosensor CDP showed an obvious fluorescence quenching response to Cu²⁺,with a quenching rate of up to 95%and a detection limit of 0.29μmol-L^-1;and the complex CDP-Cu²⁺showed an obvious fluorescence enhancement response to PPi,with a restitution rate of up to 95%and a detection limit of as low as 1.6μmol-L^-1.（3）A novel fluorescent chemosensor TM was synthesized by using rhodamine as a fluorescent group and a pyridine ring connected to a quinoline ring as a recognition group,which realized the continuous selective recognition and detection of metal cations Al³⁺and Cu²⁺.The fluorescent chemosensor TM exhibited a significant fluorescence enhancement response to Al³⁺and the fluorescence intensity was increased by 0.5-fold at 2.6-fold Al³⁺concentration.The coordination relationship between the sensor TM and Al³⁺was 2:1,and the lowest detection limit was up to 0.07μmol-L^-1,which showed high stability in the coordination response.The complex TM-Al³⁺presented a significant fluorescence quenching response to Cu²⁺with a quenching rate of 90%,with a coordination ratio of 1:1 and a detection limit of 0.15μmol-L^-1.（4）A novel fluorescent chemosensor QBD was synthesized by using fluoroboron dipyrrole（BODIPY for short）as a fluorescent moiety and introducing a polypyridine ring structure as a recognition moiety.The sensor can simultaneously achieve dual-channel recognition detection of metal cations Cu²⁺and Ag⁺,presenting a fast naked-eye recognition effect.The sensor QBD exhibits a significant fluorescence quenching response to Cu²⁺with a coordination ratio of 1:1,applicable to pH range 3～8.The sensor QBD exhibits an obvious fluorescence quenching response to Cu²⁺with a coordination ratio of 1:1 and a pH range of 3～8.The sensor QBD exhibits an obvious fluorescence enhancement response to Ag⁺with an enhancement rate of 84%,a coordination ratio of 2:1,and a pH range of 7～9.