Explaining Ionic Liquid Water Solubility in Terms of Cation and Anion Hydrophobicity

International Journal of Molecular Sciences

Johannes Ranke²  Alaa Othman¹  Ping Fan² 

[1] Medical biochemistry department, Kasr Alainy faculty of medicine Cairo University, Cairo, Egypt; E-Mail:;Abteilung Nachhaltigkeit in der Chemie, UFT Zentrum für Umweltforschung und Umwelttechnologie, Universität Bremen, Postfach 330440, 28334 Bremen, Germany; E-Mail:

关键词: Ionic liquids;    Water solubility;    Cations;    Anions;    Lipophilicity;   

DOI  :  10.3390/ijms10031271

来源: mdpi

【 摘 要 】

The water solubility of salts is ordinarily dictated by lattice energy and ion solvation. However, in the case of low melting salts also known as ionic liquids, lattice energy is immaterial and differences in hydrophobicity largely account for differences in their water solubility. In this contribution, the activity coefficients of ionic liquids in water are split into cation and anion contributions by regression against cation hydrophobicity parameters that are experimentally determined by reversed phase liquid chromatography. In this way, anion hydrophobicity parameters are derived, as well as an equation to estimate water solubilities for cation-anion combinations for which the water solubility has not been measured. Thus, a new pathway to the quantification of aqueous ion solvation is shown, making use of the relative weakness of interactions between ionic liquid ions as compared to their hydrophobicities.

【 授权许可】

CC BY   
© 2009 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland. This article is an open-access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/).