四氟硼酸盐离子液体紫外光谱和红外探针分析

发布时间：2018-03-27 19:55

本文选题：离子液体　切入点：紫外光谱　出处：《沈阳师范大学》2017年硕士论文

【摘要】：离子液体因其独特的性质成为环境友好型溶剂,离子液体是一种理想溶剂,因其不需特殊的装置或方法就可具备高收益、低废物排放等优点。与此同时,离子液体还可循环使用从而降低成本。虽然离子液体在科学和工业等方方面面都有着重要的应用,但目前的研究还处于初级阶段。总而言之,离子液体在未来将会有更好的发展。实验利用紫外光谱对HP-BF_4离子液体在乙腈、甲醇和乙醇、水中的溶液进行了定性分析,结果表明HP-BF_4离子液体的紫外光谱既会受到溶剂极性的影响也会受到溶解酸碱性的影响。由此可知,对离子液体溶液的紫外光谱进行研究时,要明确所用的溶剂。同时对HP-BF_4离子液体在乙腈、甲醇和乙醇、水溶液中定量分析,获得室温下的紫外吸收光谱曲线,在最大吸收波长下绘制出标准工作曲线,线性关系良好,采用标准加入法测定了离子液体的加标回收率。实验采用吡啶作探针,对离子液体进行了酸性和酸强度的测定。吡啶能够很好的测定离子液体的酸类型和酸强度。应用吡啶探针红外光谱法不但可以测定出离子液体的酸类型(Brφnsted/Lewis酸性),还能简单的测定出离子液体的酸强度。随着离子液体中AlCl3的摩尔分数的不断增大,离子液体的酸性不断增强。实验采用乙腈作探针检测离子液体酸类型与酸强度。结果表明乙腈能够测定离子液体的酸类型,当具有Lewis酸性的液体,会出现新的吸收峰,具有Brφnsted酸性的液体,其吸收峰只会向高波数方向产生位移,且峰型不发生改变。同时对于酸强度实验中,随着xAlCl3的值不的断增大,离子液体向着高波数方向移动,酸性不断增加。实验通过常见的荧光剂茜素红(ARS)与烷基吡啶类物质发生化学反应,生成络合物,从而改变茜素红的荧光性质。实验中,通过观察茜素红与烷基链不同的离子液体反应,考察了荧光强度的变化;烷基链的长短影响茜素红的猝灭。离子液体的浓度也影响茜素红的猝灭。当烷基链较短时,荧光荧光猝灭现象与吡啶盐离子液体的浓度无明显线性关系;当烷基链较长时,荧光猝灭现象随着烷基链增大而增大。猝灭强度与离子液体的浓度呈一定的线性关系。
[Abstract]:Ionic liquids have become environment-friendly solvents because of their unique properties. Ionic liquids are an ideal solvent because they have the advantages of high revenue and low waste emissions without special devices or methods. Ionic liquids can also be recycled to reduce costs. Although ionic liquids have important applications in science and industry, current research is still at an early stage. Ionic liquids will be better developed in the future. The HP-BF_4 ionic liquids in acetonitrile, methanol, ethanol and water have been qualitatively analyzed by ultraviolet spectroscopy. The results show that the UV spectra of HP-BF_4 ionic liquids are affected by both solvent polarity and dissolution acidity and alkalinity. At the same time, the UV absorption spectra of HP-BF_4 ionic liquids in acetonitrile, methanol and ethanol aqueous solution were quantitatively analyzed at room temperature. The standard working curve was drawn at the maximum absorption wavelength, and the linear relationship was good. The standard addition method was used to determine the recovery rate of ionic liquids. The acidity and acid strength of ionic liquids were determined. Pyridine can well determine the acid types and acid strength of ionic liquids. Not only can the acid type of ionic liquids be determined by using the infrared spectroscopy of pyridine probe, but also the acid type of Br 蠁 nsted/Lewis can be determined. The acid strength of ionic liquids can also be measured simply. As the mole fraction of AlCl3 in ionic liquids increases, The acidity of ionic liquids is increasing. The acid type and strength of ionic liquids are detected by using acetonitrile as a probe. The results show that acetonitrile can determine the acid types of ionic liquids, and a new absorption peak will appear in liquids with Lewis acidity. The absorption peak of liquid with Br 蠁 nsted acid will only shift towards high wave number, and the peak type will not change. In the acid strength experiment, the ionic liquid moves towards high wave number with the increase of the value of xAlCl3. The acidity is increasing continuously. In the experiment, the alkyl pyridine compounds react with the common fluorescent agent alizarin red ARS, and the complex is formed, which changes the fluorescence properties of alizarin red. By observing the reaction of alizarin red with different ionic liquids of alkyl chain, the change of fluorescence intensity was investigated. The length of alkyl chain affected the quenching of alizarin red. The concentration of ionic liquid also affected the quenching of alizarin red. The fluorescence quenching has no obvious linear relationship with the concentration of pyridine ionic liquids, but increases with the increase of alkyl chain when the alkyl chain is longer. The quenching intensity is linearly related to the concentration of ionic liquids.
【学位授予单位】：沈阳师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O645.1;O657.3

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