Study On Synthesis Of Phenanthroline-fluorene-based Conjugated Polymer And Their Ions Fluorescent Chemosensors

With the development of the industrial society, environmental pollution becomes moreand more serious. A large number of ions are discharged into the air, soil and water with theexhaust and sewage. These ions in the environment not only can t be decomposed by theliving beings, but also can deliver along the food chain, gather rthin the living beings anddisrupt the normal metabolism of the living beings. even threaten human health. Regardingthese lines, it is extremely urgent to look for a high selectivity and sensitivity, low cost andstable performance ion detection technique. Conjugated polymer (CP) fluorescence sensor hasbeen attracted more attention due to its high fluorescence quantum yield, molar extinctioncoefficient and peculiar sensing signal amplification effect. Now, the hot topic is to researchnovel, stable and high yield fluorescence signal group as well as a high sensitivity recognitiongroup.In this paper, fluorene with rigid plane biphenyl structural unit was the main signal group,and phenanthroline unit with nitrogen atom, which shows rigid plane structure and interactswith ions easily, also was known as recognition group. The fluorescence emission spectrum ofthe conjugated polymer was tuned by adding benzothiadiazole and4,7-dithien-2-yl-2,1,3-benzothiadiazole. The main contents include:(1) Blue light CP poly(9,9-dioctylfluorene-2,7-diyl-co-o-phenanthroline-3,8-diyl), namely,PPF, in which95%of9,9-dioctylfluorene was employed as signal group and10%phenanthroline was employed as recognition group, respectively, was synthesized by Suzukicoupling reaction using palladium as catalyst in the second chapter. And PPF wascharacterized by UV-vis absorption spectrum, fluorescence emission spectrum, gelpermeation chromatography (GPC) and TG analysis. The effects of fifteen ions, such as Cd2+,Ca2+, Hg2+, Sn2+, In3+, Pd2+, Na+, Zn2+, Cu2+, K+, Mg2+, Cl–, CO32,SO24,NO3at differentconcentrations on the fluorescence quenching behavior of PPF were studied by fluorescencephotometer. The results indicate that polymer PPF responed to not only transition metal ions,but also main group metal ions; the fluorescence peak positions of PPF at λEM=417nm is notaffected by different ion concentrations; the highest quenching efficiency is Zn2+, Pd2+, Cu2+at λEM=417nm; with increasing concentration, the intensity of fluorescence emissionof PPF increases at λEM=417nm, but Cl–,, quenched fluorescence of theemission at λEM=417nm, so PPF has a certain selectivity for the.(2) Yellow light CP poly(9,9-dioctylfluorene-2,7-diyl-co-2,1,3-benzothiadiazole-4,7-diyl-co-o-phenanthroline-3,8-diyl), namely, PPFB, in which85%of9,9-dioctylfluorene and5%benzothiadiazole were employed as signal group, and10%phenanthroline was employed as recognition group, respectively, was synthesized by Suzuki coupling reaction using palladiumas catalyst in the third chapter. It s necessary to add5%benzothiadiazole to tune thefluorescence emission spectrum of PPFB. And PPFB was characterized by UV absorptionspectrum, fluorescence emission spectrum, GPC and TG analysis. The effects of fifteen ions,such as Cd2+, Ca2+, Hg2+, Sn2+, In3+, Pd2+, Na+, Zn2+, Cu2+, K+, Mg2+, Cl–, CO32,SO24,NO3at different concentrations on the fluorescence quenching behavior of PPFB were studied byfluorescence photometer. The results indicate that polymer PPFB is similar with PPF,response for not only transition metal ions, but also for main group metal ions; thefluorescence peak positions of PPFB at λEM=415nm and λEM=542nm is not affected bydifferent ion concentrations; the highest quenching efficiency is Pd2+and Cu2+at λEM=415nm and Sn2+, Hg2+, Pd2+and Cu2+at λEM=542nm; with increasing concentration, theintensity of fluorescence emission of PPFB increases at λEM=415nm, but decreases at λEM=542nm, Cl–,, quenched fluorescence of the emission at λEM=415nm, λEM=542nm, so PPFB has a certain selectivity for the.(3) Red light CP poly(9,9-dioctylfluorene-2,7-diyl-co-di(thien-2-yl)-2,1,3-benzothia-diazole-4,7-diyl-co-o-phenanthroline-3,8-diyl), namely, PPFD, in which85%of9,9-dioctylfluorene and5%4,7-dithien-2-yl-2,1,3-benzothiadiazole were employed as signalgroup, and10%phenanthroline was employed as recognition group, respectively, wassynthesized by Suzuki coupling reaction using palladium as catalyst in the fourth chapter. It snecessary to add5%4,7-dithien-2-yl-2,1,3-benzothiadiazole to tune the fluorescenceemission spectrum of PPFD. And PPFD was characterized by UV absorption spectrum,fluorescence emission spectrum, GPC and TG analysis. The effects of fifteen ions, such as,Cd2+, Ca2+, Hg2+, Sn2+, In3+, Pd2+, Na+, Zn2+, Cu2+, K+, Mg2+, Cl–,,, atdifferent concentrations on the fluorescence quenching behavior of PPFD were studied byfluorescence photometer. The results indicate that polymer PPFD is similar with PPF,response for not only transition metal ions, but also main group metal ions; the fluorescencepeak positions of PPFD at λEM=417nm and λEM=640nm is not affected by different ionconcentrations; the highest quenching efficiency is Pd2+and Cu2+at λEM=417nm and Sn2+,Hg2+, Mg2+, Pd2+and Cu2+at λEM=640nm; with increasing concentration, theintensity of fluorescence emission of PPFD increases at λEM=417nm, but decreases at λEM=640nm, Cl–,, quenched fluorescence of the emission at λEM=417nm, λEM=640nm, so PPFD has a certain selectivity for the.