Preparation And Ion Recognition Of Novel Conjugated Polymers Based On Quinoline

As the focus of the novel material fields,conjugated polymers have attracted much attention from researchers.Due to the long conjugated backbone and free movement of electronics,conjugated polymers realize signal amplification.Thanks to these outstanding properties,conjugated polymers are widely used as organic light-emitting diodes(OLEDs),thin film transistors,solar cells and chemical sensors.Conjugated polymers essentially consist of main and side chains.Therefore,how to obtain efficiently photoelectric materials by designing and utilizing the space winding of main and side chain becomes a hot scientific issue.It is known to all,quinoline and its derivatives possess high fluorescence quantum yield,excellent electronic transport properties,and outstanding chelating ability to metal ions,which prove that quinoline is a potential fluorescence material.Based on above ideas,two novel conjugated polymers with quinoline modifying in main or side chains were synthesized.Then,the thermal stability and photoelectric properties were studied.Considering the specific binding sites and spatial structures,detection to ions of fluorescent materials were also explored.This thesis includes the following four chapters:The first chapter: The latest research progress of polymer and its application in the fields of detection are introduced briefly.Then design ideas of this thesis are put forward.The second chapter: Based on the ideas of investigating the properties of conjugated polymer materials with quinoline as the main chain,a novel conjugated polymer containing benzene and quinoline was successfully synthesized.UV-vis absorption and fluorescence emission of the polymer are 325 nm and 430 nm,respectively,which indicate the polymer is a typical blue-emitting material.And the conjugated polymer possesses excellent thermal stability and electrical properties.Considering the specific binding sites,detection to ions of the fluorescent materials was also explored.The results showed that the fluorescence of the polymer was efficiently quenched only in the presence of Fe(III)without interference from other ions.Furthermore,detection of the probe to Fe(III)in cell was proved to be feasible.The innovations of this work lie in utilizing a simple strategy to introduce quinoline into the main chain of the polymer.And the polymer can realize the selective recognition to Fe(III),which provides a feasible idea for the development of conjugated polymers as fluorescent probes.The third chapter: According to the above research,it was found that the fluorescent probes to ions were easily disturbed in biological system.And blue and green fluorescent materials displayed large background interference,which limited their applications.Based on this,in order to obtain a red-emitting conjugated polymer which showed fluorescence “turn-on” towards ions,red-emitting thiophene derivatives were introduced as the main chain,and the quinoline was modified in the side chain.Spectral experiments showed that the polymer is a red-emitting material with the UV-vis absorption and fluorescence emission of 490 nm and 610 nm,respectively.Additionally,the polymer exhibits excellent thermal stability and electrical properties.The detection study of the polymer to metal ions indicated the fluorescence of the conjugated polymer was obviously enhanced in the presence of Hg(II)ions without interference from other ions.The results showed that the polymer was able to recognize Hg(II)selectively.Furthermore,the detection towards Hg(II)in actual sample(cosmetic)was also implemented.In this work,a novel fluorescent probe with long wavelength was successfully prepared by appropriate design and modification.And the probe displayed a selectively fluorescent enhancement to Hg(II),which provided a theoretical guidance and application platform for quinoline compounds as fluorescent materials.The fourth chapter: Summary and outlook.