RAIRS Investigations on Films of the Ionic Liquid [EMIM]Tf2N

Abstract

The reflection-absorption infrared (RAIRS) spectra of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM]Tf2N) are presented for liquid as well as for amorphous and crystalline solid films. The liquid and amorphous films show rather similar spectra, indicating that the film structure is similar in both cases. On the other hand, these spectra differ considerably from those of crystalline films, indicating that the film structure is different for liquid and crystalline films. There are however indications that in all of the studied phases, including the crystalline state, the cation interaction with the SO2 groups of the anion dominates.

In situ PM-IRRAS of a glassy carbon electrode/deep eutectic solvent interface

“…8,9 In situ measurements such as X-ray reflectometry 10 and atomic force microscopy 11 have been used to investigate the near-surface structure of the electrode/RTIL interface. 25,26 Spectroscopic and theoretical investigations on electrified electrode/ionic liquid interfaces suggest that the electrode surface acts as an electronic and structural template, where cations adsorb at potentials negative of the potential of zero charge (PZC) and that at potentials positive of the PZC the cations are replaced by anions. 12 Consequently, mass transport and charge transfer kinetics of electrode reactions can be significantly affected leading to unexpected electrochemical outcomes.…”

“…25,26 The temperature effect was investigated and the thin-film IRRAS spectra were compared to those of the bulk liquids. 25,26 The temperature effect was investigated and the thin-film IRRAS spectra were compared to those of the bulk liquids.…”

“…25,26 The temperature effect was investigated and the thin-film IRRAS spectra were compared to those of the bulk liquids. 25 Polarization modulation is based on the surface selection rule, 36 which state that the p-polarized radiation is absorbed by surface and liquid phase species, whereas the s-polarized light is only absorbed by the species in the liquid phase. 25 Polarization modulation is based on the surface selection rule, 36 which state that the p-polarized radiation is absorbed by surface and liquid phase species, whereas the s-polarized light is only absorbed by the species in the liquid phase.…”

“…[13][14][15] Several surface sensitive spectroscopic techniques have been used to investigate RTIL/electrode interfaces, including sum frequency generation (SFG), [16][17][18][19] surface-enhanced Raman spectroscopy (SERS), 20,21 surface-enhanced infrared absorption spectroscopy (SEIRAS), 22,23 subtractive normalized interfacial Fourier transform infrared spectroscopy (SNIFTIRS) 24 and infrared reflection absorption spectroscopy (IRRAS). 25,26 Spectroscopic and theoretical investigations on electrified electrode/ionic liquid interfaces suggest that the electrode surface acts as an electronic and structural template, where cations adsorb at potentials negative of the potential of zero charge (PZC) and that at potentials positive of the PZC the cations are replaced by anions. 6,[27][28][29] However, this potential-dependent re-arrangement of cations and anions is not that simple and adsorption-desorption hysteresis 19,22 as well as ultra-slow restructuring 30,31 have also been reported.…”

Changes of the near-surface chemical composition of the 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide room temperature ionic liquid under the influence of irradiation

“…9 In plasma processing as well as in material characterisation, the ionic liquids are exposed to high energy photons and electrons that can have an impact on the chemical reactions taking place or in worst case can be the cause of degradation effects in the material. Especially in some analytical methods such as photoelectron spectroscopy, [10][11][12][13][14] infrared spectroscopy, 15 Raman spectroscopy 16 or Auger electron spectroscopy, the ILs are exposed to different kinds of radiation by photons or electrons. A commonly used analytical method for the surface characterisation of different ionic liquids is XPS where monochromated or non-monochromated X-ray radiation is used for excitation.…”