3-羟基黄酮在不同极性和酸碱度溶剂中的光谱研究  

Spectroscopic Investigation of 3-Hydroxyflavone in Different Polarity and pH Values Solutions

作　　者：马丽娜[1] 南景宇[1,2] 吴峰[1] 田玮[1] 陈文驹[1] 张桂兰[1] 

机构地区：[1]南开大学现代光学研究所、教育部光电信息技术科学开放实验室,天津300071 [2]河北北方学院物理系,河北张家口075000

出　　处：《光谱学与光谱分析》2009年第4期994-998,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(60178025)资助

摘　　要：实验观测了3-羟基黄酮(3-HF)在不同极性溶剂中的吸收光谱和荧光光谱,发现在吸收光谱中有3个吸收带,峰值位于300和345nm的两个吸收带较强,位于415nm处的吸收带较弱。用345nm作为激发光,观测到两个荧光带,其中峰值位于400nm的荧光带为3-HF稀醇式构型的发射,随着溶剂极性的增大其强度增强,峰值位于526nm的荧光带为3-HF互变异构体的发射,随着溶剂极性的增大其强度减弱,这表明溶剂极性阻碍质子转移的发生。用415nm的光激发样品,在荧光光谱中发现了3个新荧光谱带,峰值分别位于440,471和515nm,这3个荧光谱带归属至今未见报道。为了指认这3个荧光谱带,分别观测了3-HF在不同酸碱度溶液的荧光光谱及其吸收光谱,通过对这些光谱的分析研究,指认出荧光峰位于440和471nm的荧光谱带为3-HF的两种阳离子的发射,峰值位于515nm的荧光谱带为3-HF的阴离子的发射。The absorption and fluorescence spectra of 3-hydroxyflavone （3-HF） in different polar solvents were observed with UV-Vis spectrometer and fluorescence spectrometer, respectively. There are three absorption bands in the absorption spectra, wherein two absorption bands with absorption peak at 300 and 345 nm, respectively, are strong, and the other one with absorption peak at 415 nrn is weak. When the samples in different polar solvents were excited by 345 nm light, there appeared two new fluorescence bands peaked at 400 and 526 nm, respectively. The fluorescence band at 400 nm is attributable to the emission from enol structure and its intensity increases with increasing the polarity of protic solvents; that at 526 nm is attributable to the emission from the isomer structure and its intensity decreases with increasing the polarity of protic solvents. The results show that the increase in the polarity of protic solvents prevents the formation of isomer. When the samples in different polar solvents were excited by 415 nm light, three new fluorescence bands peaked at 440,471 and 515 nm have not been reported so far. In order to identify the three new fluorescence bands, we prepared the samples with pH value of 5. 0, 4.0 and 3.0 through incorporating the different amounts of aeetie acid into 3-HF solution. The fluorescence spectra in different pH value solution were observed under excitation of 415 nm light, and it was found that the intensity of two fluorescence bands in the region of shorter wavelength chan-ges with pH values changing. For identifying the fluorescence band of 515 nm peak wavelength, we put sodium hydroxide into 3-HF in ethanol solution and prepared 3-HF samples with pH values of 8.0, 8.5, 9.0, and 10. 0. When the samples were excited by the 415 nm light, it was found that two fluorescence bands in the region of shorter wavelength disappeared and the intensity of the fluorescence band of 515 nm was enhanced. Since in sodium hydroxide solution 3-HF forms anion easily, we ascribed the fluorescence b

关 键 词：3-羟基黄酮(3-HF) 激发态质子转移 阳离子 阴离子 吸收光谱 荧光光谱 

分 类 号：O434.1[机械工程—光学工程]