Synthesis And Metal Ions Recongnition Ability Of Novel Conjugated Polymers With Fluorene

Metal ions can maintain body healthy and ecological balance but they are also the reasons of the human diseases and the pollution of environment.So people have been paying a lot of attention on the measurement of the detection of metal ions..In recent years,fluorescent chemical sensor is widely concerned because of cheapness,easy operation,sensitive signal and little interference from the outside,and the specific detection of various metal ions is realized successfully by using it.In this paper we will elaborate the recognition performance about different metal ions in aqueous of two novel conjugated polymers of based on fluorine.Taking 2,7-dibromofluorene,1,6-dibromohexane and N,N-Dimethylformamide(DMF)as raw material,a monomer with two aldehyde based on fluorine was obtained via two step of substitution reaction.The synthesis of monomer was polycondensated with 1,2-diaminobenzene and 2,3-diaminopyridine in DMF using Lithium Chloride for catalytic polycondensated to yield two kinds of conjugated polymers(P1 and P2)which main chains contain polyimide group.Then two kinds of ionic conjugated polymers(IP1 and IP2)were gained by modificating with quaternary ammonium cations on side chains of polymers.The structure of monomer and polymers were characterized by FT-IR and 1H NMR.The effects of different solvents and pH conditions on the conjugated polymers were tested with ultraviolet-visible spectrum and fluorescence spectrum.From the experimental results we found that different solvents make no difference on ultraviolet-visible spectrum of polymer,but fluorescence spectrum of polymers in water is quite from that in other solvents;and change of environment pH has a great effect on optical property of polymers.The recognition performance about different metal ions in aqueous of two novel conjugated polymers is investigated by fluorescence spectrum.The Cu2+ can be identificated with none interference from other ions in water by IP1 with fluorescence spectrum.The fluorescence peak value of IP1 at 405nm was quenched to 1/5 of the blank sample in PBS neutral buffer solution after adding 50 equivalents Cu2+.The complex ratio of IP1 and Cu2+probably was 2:1 by the experimental data.The Fe3+,Cu2+ and Co2+ can be recognited in water by IP2 with fluorescence spectrum.The fluorescence peak value of IP2 was quenched to 1/20 of the blank sample in PBS neutral buffer solution after adding 20 equivalents Fe3+with max-emission wavelength redshifting from the initial 382 nm to 436 nm.The complexratio of IP2 and Fe3+ probably was 1:1 by the experimental data.The fluorescence peak value of IP2 at 382 nm was quenched to 1/2 of the blank sample in PBS neutral buffer solution after adding 20 equivalents Cu2+.The complex ratio of IP2 and Cu2+ probably was 2:1 by the experimental data.The fluorescence peak value of IP2 at 382nm was enhanced to 1.8 time of the blank sample in PBS neutral buffer solution after adding 20 equivalents Co2+.The complex ratio of IP2 and Co2+ probably was 1:1 by the experimental data.