Solvatochromic and preferential solvation of fluorescein in some water-alcoholic mixed solvents
Solvatochromic and preferential solvation of fluorescein in some water-alcoholic mixed solvents
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DOI：
10.1016/j.molliq.2013.10.028
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发表时间：
2014-02
影响因子：
6
通讯作者：
F. Naderi;A. Farajtabar;F. Gharib,
中科院分区：
文献类型：
--
作者：
F. Naderi;A. Farajtabar;F. Gharib,
氢键对荧光素的光谱性质有重要影响，但氢键与荧光素在混合溶剂中的溶液行为和优先溶剂化的关系尚不清楚。本文研究了298.15K时荧光素阴离子在纯水、甲醇、乙醇、正丙醇、正丙醇、二甲基亚砜、N，N-二甲基甲酰胺、乙腈以及水与上述醇的二元混合物中的吸收光谱。光谱的变化进行了解释，在特定的和非特定的溶质-溶剂相互作用。计算了各二元混合物的最大吸收电子跃迁能量。在线性溶剂化能关系的框架下，分析了溶质-溶剂相互作用对ET的影响程度和重要性。在所有二元混合物中，优先溶剂化被检测为ET曲线相对于醇的分析摩尔分数的非理想行为。ET值被拟合到溶剂交换模型以计算优先溶剂化参数。从溶剂-溶剂和溶质-溶剂相互作用的角度讨论了荧光素双价阴离子优先被溶剂化物种溶剂化的现象。
It is known that the hydrogen bonding has a significant effect on the spectral properties of fluorescein, however its relevance to solution behavior and preferential solvation of fluorescein is unclear in mixed solvents. In this work, absorption spectra of fluorescein dianion have been investigated in pure water, methanol, ethanol, 1-propanol, 2-propanol, dimethylsulfoxide, N,N-dimethylformamide, acetonitrile and in binary mixtures of water with the mentioned alcohols at 298.15 K. Spectral changes were interpreted in terms of specific and nonspecific solute-solvent interactions. The energy of electronic transition in maximum absorption (ET) was calculated in each binary mixture. The extent and importance of each of solute–solvent interactions toETwere analyzed in the framework of the linear solvation energy relationships. Preferential solvation was detected as a nonideal behavior ofETcurve respective to the analytical mole fraction of alcohols in all binary mixtures. TheETvalues were fitted to a solvent exchange model to calculate the preferential solvation parameters. The preference of fluorescein dianion to be solvated by one of the solvating species relative to others was discussed in terms of solvent–solvent and solute–solvent interactions.