title: New interpretation of the CH stretching vibrations in imidazolium-based ionic liquids.
abstract: In ionic liquids composed of alkyl-substituted imidazolium cations and weakly coordinating anions such as bis(trifluoromethanesulfonyl)imide, (CF(3)SO(2))(2)N(-), the stretching vibrations of the imidazolium CH groups are shown to interact by Fermi resonance with the overtones and the combination of two in-plane ring vibrations. This new assignment, based on isotopic substitutions and anharmonic frequency calculations for gas phase cations, implies that these imidazolium cations do not establish any strong and directional C-H...anion hydrogen bond.
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Lassègues
authors.forename: Joseph
authors.initials: J
authors.lastname: Grondin
authors.forename: Dominique
authors.initials: D
authors.lastname: Cavagnat
authors.forename: Patrik
authors.initials: P
authors.lastname: Johansson