Probing Solute Clustering in Supercritical Solutions Using Solvatochromic Parameters

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• 作者：Andrew P. Abbott ; Eric G. Hope ; Donna J. Palmer
• 刊名：Journal of Physical Chemistry B
• 出版年：2007
• 出版时间：July 19, 2007
• 年：2007
• 卷：111
• 期：28
• 页码：8119 - 8125
• 全文大小：340K
• 年卷期：v.111,no.28(July 19, 2007)
• ISSN：1520-5207

文摘

Kamlet and Taft polarity parameters are presented for three supercritical solutions containing solutes of differentpolarities at two concentrations. It is shown that the polarizability and hydrogen-bond-donating ability changesignificantly with pressure. In the lower pressure regime, naphthalene and salicylic acid cause a decrease inthe polarity parameters compared with the pure fluid, whereas toluic acid causes an increase. These differencescan be explained in terms of solute-solute and solute-indicator clustering. It is shown that there is, however,a direct correlation between the change in the hydrogen-bond-donating ability and polarizability for all solutesand all pressures and concentrations, which is thought to result from changes in the amount of solvent requiredto solvate the solute.