This work has been supported by the DFG Priority Programme 1191 “Ionic Liquids” and by the DFG Sonderforschungsbereich SFB 652. We thank Verlaine Fossog (Physikalische Chemie, Universität des Saarlandes) for providing us with the protic ionic liquid TEAMS.
Ion Speciation of Protic Ionic Liquids in Water: Transition from Contact to Solvent-Separated Ion Pairs†
Article first published online: 10 FEB 2013
Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Angewandte Chemie International Edition
Volume 52, Issue 10, pages 2990–2994, March 4, 2013
How to Cite
Stange, P., Fumino, K. and Ludwig, R. (2013), Ion Speciation of Protic Ionic Liquids in Water: Transition from Contact to Solvent-Separated Ion Pairs . Angew. Chem. Int. Ed., 52: 2990–2994. doi: 10.1002/anie.201209609
- Issue published online: 27 FEB 2013
- Article first published online: 10 FEB 2013
- Manuscript Received: 30 NOV 2012
- density functional calculations;
- hydrogen bonding;
- ionic liquids;
- IR spectroscopy
The fab four: Far-infrared difference spectra and DFT-calculated properties for mixtures of protic ionic liquids (PILs) and water clearly indicate that a minimum of four water molecules are needed to transfer contact (CIPs) into solvent-separated (SIPs) ion pairs. SIPs are favored over CIPs owing to additional H-bonds and cooperative effects. This enthalpic advantage overcompensates for the entropic penalty of separation by water.