...
首页> 外文期刊>The journal of physical chemistry, B. Condensed matter, materials, surfaces, interfaces & biophysical >Intrazeolite Photochemistry. 22. Acid-Base Properties of Coumarin 6. Characterization in Solution, the Solid State, and Incorporated into Supramolecular Systems
【24h】

Intrazeolite Photochemistry. 22. Acid-Base Properties of Coumarin 6. Characterization in Solution, the Solid State, and Incorporated into Supramolecular Systems

机译:沸石内光化学。 22.香豆素的酸碱性质6.在溶液中的表征,固态,并结合到超分子体系中

获取原文
获取原文并翻译 | 示例

摘要

The spectroscopic properties of the dye coumarin 6 in solution are reported. Relatively large shifts are seen in both the absorption and fluorescence spectra upon protonation. The very large Stokes shift that is seen for the dye in its solid state and as the hydrochloride salt reveals that the dye molecules are forming aggregates, which is a phenomenon that is also seen in very high concentrations of coumarin 6 in solution. The acid-base properties of coumarin 6 in heterogeneous systems such as zeolites and clays are also presented. We have found that this dye molecule is extremely sensitive to the presence of Lewis and Br#nsted sites and were able to detect acidity in the faujasite zeolite NaY which is usually considered to be nonacidic. Two series of faujasite zeolites, one in which the Br#nsted acidity increases and the other in which the Lewis acidity increases, were also studied. The dication of the dye was detected in both HY100 and CBV 740, the zeolites with the highest Br#nsted and highest Lewis acidity, spectively, used in the present study. Due to the large shifts seen for coumarin 6 in its neutral, monocation, and dication forms, both the absorption and fluorescence spectra resulted in detection of two species of the dye in those zeolites with intermediate acidity. The ability of coumarin 6 to sense small amounts of Lewis and Br0nsted sites makes it an attractive molecule to study other systems as well.
机译:报道了溶液中染料香豆素6的光谱性质。质子化时在吸收光谱和荧光光谱中都可以看到相对较大的偏移。对于固态染料和盐酸盐而言,染料的斯托克斯位移非常大,这表明染料分子正在形成聚集体,这种现象在溶液中香豆素6的浓度很高时也可以看到。还介绍了香豆素6在非均相系统(如沸石和粘土)中的酸碱性质。我们发现该染料分子对路易斯和布朗斯台德位点的存在极为敏感,并且能够检测八面沸石NaY(通常被认为是非酸性)中的酸性。还研究了两种八面沸石,一种是Br#nsted酸性增加,另一种是Lewis酸性增加。在本研究中使用的HY100和CBV 740中,分别检测到最高Br#nsted和最高Lewis酸度的沸石,检测到了染料的指示。由于香豆素6呈中性,单阳离子和双阳离子形式发生了较大变化,因此吸收光谱和荧光光谱均导致在中等酸性的沸石中检测到两种染料。香豆素6能够感知少量Lewis和Brnsted位点的能力也使其成为研究其他系统的诱人分子。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号