Construction Of A Novel Fluorescent Probe Based On Cucurbit[5]uril(Q[5] Derivatives

The Cucurbit[n]uril（Q[n]）is a new type of artificial receptor developed after crown ether,cyclodextrin and calixarene.Compared with crown ether,cucurbit[n]uril（Q[n]）has stronger coordination effect and more stable complex,which has great advantages in molecular recognition.Due to common cucurbit[n]uril（Q[n]）no fluorescence effect,based on supramolecular supramolecular fluorescence probe to detect metal ions have to rely on with the molecules involved in fluorescence effect,makes the cucurbit[n]uril（Q[n]）supramolecular fluorescence probe is restricted,and will be connected to the cucurbit[n]uril（Q[n]）fluorescent groups at synthesis with fluorescent tags cucurbit[n]uril（Q[n]）derivatives is a kind of good method.Trexene and its derivatives are ideal fluorophores for the construction of high efficient multifunctional fluorescent probes.Trexene has high molar absorption coefficient and fluorescence quantum yield,strong thermal stability and easy to be synthesized and modified.In this paper,on the basis of（HO）₁Q[5]and trexene,a derivative of（HO）₁Q[5]and trexene（Q[5]-Tr）was synthesized and a fluorescent probe was constructed.The properties of the probe,the screening and recognition performance of the probe for different metal ions were studied.The main research contents are as follows:1.General cucurbit[n]uril（Q[n]）was synthesized with glycoluril as raw material,and Q[5]was separated and purified by column chromatography.（HO）₁Q[5]was synthesized by ammonium persulfate and sodium bisulfite oxidation method on the basis of reference.（HO）₁Q[5]was separated and purified by silica gel column chromatography,and the target product was characterized by infrared spectrum and¹H-NMR.2.Use 1-indanone in glacial acetic acid and the mixture of concentrated hydrochloric acid after many aldol condensation and dehydration reaction cyclization trexene crude product,reaction with anhydrous sodium carbonate and not fully acid,using water,acetone,methylene chloride to cleaning of crude product,trexene product had high purity,and by using IR,¹H-NMR were characterized.3.With n-butyllithium as hydrogen extraction reagent,using 1,6-dibromohexane replace trexene C5 hydrogen preparation of 5-hexyl bromide generation trexene,collect the organic phase,the column chromatography separation and purification on the collected organic phase,thin layer chromatography（TLC）,high purity was obtained 5-hexyl bromide generation trexene,and by using IR,¹H-NMR and high resolution mass spectrometry to characterization.4.Using（HO）₁Q[5]and 5-hexyl bromide generation trexene as raw materials,the derivatives of（HO）₁Q[5]and trexene（Q[5]-Tr）were prepared and characterized by IR and ¹H-NMR.5.A fluorescent probe Q[5]-Tr was constructed on the basis of a（HO）1Q[5]-trexene derivative synthesized in laboratory.The fluorescence emission spectra of trexene,5-hexyl bromide generation trexene and probe Q[5]-Tr were compared.The screening and recognition performance of the probe for different metal ions were studied.Probe in DMF/H₂O（v/v,8/2,pH=7）under the condition of selective Cu²⁺,Pb²⁺,Fe^3+,Fe²⁺,Ag⁺,the ratio of 1:1,measuring time can be controlled within 2～10 min,with high sensitivity.In addition to the poor anti-interference ability of Ag⁺,the probe has good anti-interference ability to identify the other four metal ions.The difference of fluorescence emission intensity between probe Q[5]-Tr and（Q[5]-Tr+metal ion）is linear with the concentration of metal ions.On the reproducibility of test methods,intra-day RSD%between 0.38%to 2.40%and inter-day RSD%between 0.68%to4.65%of the probe Q[5]-Tr and Q[5]-Tr+metal ions.The standard addition method was used to study the recovery rate of Cu²⁺,Pb²⁺,Fe³⁺,Fe²⁺,Ag⁺.Among them,the average recovery rate in metal ions is in the range of 76.3%-93.8%,RSD%is in the range of 0.27%-1.10%.The results show that the probe Q[5]-Tr has wide linear range,low detection limit and good precision,which can satisfy the requirement of trace analysis of metal ions in actual water samples.