Abstract
Crystal structures of two examples of an important class of ionic liquids, 1,3-dimethylimidazolium and 1,2,3-triethylimidazolium bis(trifluoromethanesulfonyl)imide have been characterized by single crystal X-ray diffraction. The anion in the 1,3-dimethylimidazolium example (mp 22 degreesC), adopts an unusual cis-geometry constrained by bifurcated cation-anion C-H...O hydrogen-bonds from the imidazolium cation to the anion resulting in the formation of fluorous layers within the solid-state structure. In contrast, in the 1,2,3-triethylimidazolium salt (mp 57 degreesC), the ions are discretely packed with only weak C-H...O contacts between the ions close to the van der Waals separation distances, and with the anion adopting the twisted conformation observed for all other examples from the limited set of organic bis( trifluoromethanesulfonyl) imide crystal structures. The structures are discussed in terms of the favorable physical properties that bis(trifluoromethanesulfonyl) imide anions impart in ionic liquids.
Original language | English |
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Pages (from-to) | 2267-2271 |
Number of pages | 5 |
Journal | Dalton Transactions |
Volume | 4 |
Issue number | 15 |
DOIs | |
Publication status | Published - 07 Aug 2004 |
Externally published | Yes |
Keywords
- Crystal structures
- Hydrogen bonding
- Ionic liquids
- Structural studies
- X-ray diffraction, X-ray powder diffraction
ASJC Scopus subject areas
- General Chemistry