荧光光谱滴定法研究葫芦脲[7]对亚甲基蓝的包结作用  

Study on the Inclusion Behavior of Cucurbit[7] Uril with Methylene Blue by Spectrofluorometric Titrations

作　　者：余化鹏[1] 孙军勇[1] 吴炼[1] 徐洪伟[1] 王伦[1] 周运友[1] 

机构地区：[1]安徽省化学生物传感重点实验室、安徽师范大学化学材料科学学院,安徽芜湖241000

出　　处：《光谱学与光谱分析》2009年第4期1041-1044,共4页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(20875002);安徽省教育厅教学研究基金项目(JYXM2003174)资助

摘　　要：采用荧光光谱滴定法研究了不同温度下及醋酸缓冲溶液中,葫芦脲[7](CB7)对亚甲基蓝(MB)的包结作用。在一定的浓度范围内,体系的荧光强度随着CB7浓度的增大而增强,且荧光峰位有一定的蓝移,结果显示二者形成了1∶1的包结配合物,同时计算了它们的包结稳定常数以及相关热力学常数ΔG,ΔH和ΔS,热力学常数数值说明反应是焓变驱动的。此外,利用1H NMR谱图,结合葫芦脲[7]以及客体亚甲基蓝的结构特征,对其包结机理及主客体作用模式进行了探讨。The characteristics of host-guest complexation between cucurbit [7] uril （CB7） and methylene blue （MB） were inves-tigated by fluorescence spectrometry in acetate buffer solution at room temperature. It was found that the fluorescence intensity of methylene blue regularly increased upon the addition of cucurbit [7] uril accompanying with a blue-shift of the position of the emission maximum. The results indicate the formation of complex between CB7 and MB at a 1 ： 1 complex stoiehiometry and the association constant was calculated by applying a deduced equation. ^1H NMR spectra were applied to to complement the fluorescence work to verify the formation of the complex. From the temperature dependence of the equilibrium constants, thermodynamics parametersH ands values were obtained, indicating an enthalpic driving force for eomplexation. The possible interaction mechanism was also discussed. This work may extend the application range of cueurbit [7] uril in biochemistry and pharmaceutical analysis.

关 键 词：葫芦脲[7] 亚甲基蓝 荧光光谱滴定法 主客体包结作用 包结稳定常数 

分 类 号：O657.3[理学—分析化学]