Synthesis And Spectroscopic Properties Of Aryl Imidazole And Luminol Derivatives

Luminol is a classic chemical reagent It is widely used in chemiluminescent analysis,bioluminescent analysis and immunohistochemistry.Luminol has high fluorescence and chemiluminescent intensity,but it also has low stability and short chemiluminescent duration.The aryl imidazoles have unique physical and chemical properties,so it can serve as enhancers to improve the stability of luminol chemiluminescence and to prolong the chemiluminescent duration.The reaction condition for synthesizing arylimidazole enhancers is stringent,such as difficult to separate and purify,low in purity,so it mainly relies on imports and its price is expensive.Therefore,it is significance to find new synthetic methods of luminol derivatives and aryl imidazole enhancers with excellent properties.Based on the literature review,the main jobs of this thesis can be concluded as follows:1.Four series of N-alkyl substituted luminol have been synthesized and their spectral properties are studied.The results show that starting from 3-nitrophthalic acid,the target compound are synthesized effectively by five steps of anhydride,methylation,reduction,substitution and hydration.Their structures are characterized by 'H NMR,13C NMR and IR spectrum.In DMSO-PBS buffer,with the increase of the N-alkyl chain,the absorption wavelength has undergone a red shift in UV spectrum.In the fluorescence spectrum,N-alkyl substitution can make luminol undergone a red shift,and the emission wavelength are shifted by 15 nm in comparison with luminol.The pH of the solution has a great influence on the fluorescence spectrum of the N-alkyl substituted luminol,and its fluorescent intensity is basically stable under neutral and alkaline conditions.The fluorescence intensity of the N-alkyl substituted luminol was gradually increased with their concentration in the range of 0.1-5[LM.Fluorescent intensity:N-propyl luminol>N-ethyl luminol>N-butyl luminol>N-nonyl luminol>luminol.Metallic copper ions can reduce the fluorescent intensity of N-alkyl substituted luminol.With the increase of luminol alkyl chains,the stronger linear relationship between Cu2+concentration and its fluorescent intensity can be found.The fluorescent intensity of N-nonyl luminol has a good linear relationship with Cu2+concentration.2.Based on the synthesis of arylimidazole luminescence enhancer about 4-(4-methyl-4,5-dihydro-1H-imidazol-2-yl)phenol(Z),a new chemiluminescence system of Luminol-H2O2-HRP-Z was established.The results show that the method of one-step synthesis target compounds by using p-hydroxybenzoic acid and 1,2-propanediamine as raw materials and boric acid as a catalyst has the advantages of easy availability of raw materials,simple process,high yield and easy purification.Their structures are characterized by 1H NMR and 13C NMR.The various factors affecting the Luminol-H2O2-HRP-Z system have been optimized,such as the concentration of luminol and enhancer,the pH of 0.1 M Tris HCl buffer solution.Under the conditions,the chemiluminescent intensity has a good linear relationship with concentration of HRP in the range of 0.005-0.5?g·mL-1.While arylimidazole enhancers(Z)is used for chemiluminescent system of luminol and its derivatives,the chemiluminescent intensity of the system is enhanced obviously,and duration of the light emission is more than 25 min.The chemiluminescent intensity is basically the same as the fluorescent intensity in the DMSO-PBS buffer.In summary,the results show that the introduction of alkyl chains to luminol can enhance its stability,the fluorescent and chemiluminescent intensity effectively.Based on the synthesis of enhancer Z,a new chemiluminescence system for enhancing luminol and its derivatives is constructed,the foundation for their further development and applications have been established.