title: Nonlinear vibrational spectroscopic studies on waterlionic liquid([C(n)mim]TFSA: n = 4, 8) interfaces.
abstract: The interfaces of water/room temperature ionic liquids (RTIL) (1-alkyl-3-methyl imidazolium bis(trifluoromethylsulfonyl)amide ([C(n)mim]TFSA): n = 4, 8) are investigated by infrared-visible sum frequency generation (IV-SFG) vibrational spectroscopy and molecular dynamics (MD) simulation. SFG spectra taken within the SO stretch region drastically differ between air/RTIL and water/RTIL interfaces. When a RTIL surface is in contact with water, a broadened and blue-shifted SO2-ss mode peak is observed in the SFG spectra, indicating an inhomogeneous intermolecular interaction due to hydrogen bonding of the [TFSA]- anions and water molecules at the water/[C(n)mim]TFSA interface. MD simulations show the SO2 groups of the anion are preferentially orientated toward the water phase, which is consistent with the SFG spectral features. Polar orientation of the [TFSA] anion originates from the ordered structure of the alkyl chains of [C(n)mim]+ cations.
authors.affiliation: Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, 464-8602, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Iwahashi
authors.forename: Yasunari
authors.initials: Y
authors.lastname: Sakai
authors.forename: Doseok
authors.initials: D
authors.lastname: Kim
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Ishiyama
authors.forename: Akihiro
authors.initials: A
authors.lastname: Morita
authors.forename: Yukio
authors.initials: Y
authors.lastname: Ouchi
mesh_terms: D052578:Ionic Liquids / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D013055:Spectrophotometry, Infrared; D014732:Vibration; D014867:Water / Q000737:chemistry*
chemical_list: D052578:Ionic Liquids; D014867:Water