Physical Properties of Chiral Ionic Liquids Based on (–)-Menthol

Abstract

In this study, the significant effect of the cationic structures of chiral ionic liquids on their physical properties has been shown. An analysis has been made for the structure of ammonium, alkylimidazolium, alkoxymethylimidazolium, and pyridinium bis(trifluoromethanesulfonyl)imides. Comparison of physical properties of different liquid salts was made for the density, viscosity, thermal degradation, and glass transition temperature.

The lowest density and viscosity are characteristic of the 1-[(1R,2S,5R)-(–)-menthoxymethyl]-3-alkylimidazolium bis(trifluoromethanesulfonyl)imides and the trialkyl[(1R,2S,5R)-(–)-menthoxymethyl]ammonium bis(trifluoromethanesulfonyl)imides. Moreover, the largest liquid range characterized the 3-alkoxymethyl-1-(1R,2S,5R)-(–)-menthoxymethylmidazolium bis(trifluoromethanesulfonyl)imides.

GRAPHICAL ABSTRACT

Keywords:

• Ionic liquids
• chirality
• (1R,2S,5R)-(—)-methanol
• bis(trifluoromethanesulfonyl)-imides derivatives

Acknowledgments

The work was financed by a statutory activity subsidy from the Polish Ministry of Science and Higher Education for the Faculty of Chemistry of Wrocław University of Technology.