Alkyl-chain dividing layer at an alcohol/ionic liquid buried interface studied by sum-frequency generation vibrational spectroscopy

Abstract

We demonstrate for the first time the formation of a non-polar alkyl-chain dividing layer between a room-temperature ionic liquid (RTIL) and an n-alcohol. This newly described non-polar interfacial layer, which should be more hydrophobic than both RTIL and alcohol phases, might find applications in liquid/liquid reaction systems, or serve as a soft nano-functional space.

Nonlinear vibrational spectroscopic studies on water/ionic liquid([Cnmim]TFSA: n = 4, 8) interfaces

“…f 1 and f 2 are the incident and refracted angles of the light, respectively, and n 0 (u) is the empirical refractive index of the interfacial layer. 19,21 In the case of an azimuthally isotropic interface, there are only four independent nonvanishing components of cs: e c XXZ ¼ c YYZ , c XZX ¼ c YZY , c ZXX ¼ c ZYY , and c ZZZ in space-fixed coordinates. These components are chosen such that Z is along the surface normal and X is in the incidence plane.…”

“…The width and position of the SO 2 -ss mode peak at the water/[C n mim]TFSA interfaces are much broader and blueshifted relative to that at the air/[C n mim]TFSA interface, indicating that the SO 2 groups of the [TFSA] À anion undergo a strong intermolecular interaction in an inhomogeneous microscopic environment. 14,18,19 The SO 2 group is a polar moiety; hence such drastic changes in the microscopic interaction are due to the presence of the hydrogen bonding of the [TFSA] À anion with water molecules. Furthermore, the [TFSA] À anion observed in the SFG spectra assumes the C 1 conformer, as shown in Fig.…”

“…Therefore, the liquid/liquid interfaces of RTILs and conventional molecular liquids may also possess anomalous microscopic structural formation. 18,19 Consequently, the discovery and elucidation of novel liquid/liquid interfacial structures should trigger the development of new reaction systems.…”

Solvation of Inorganic Nitrate Salts in Protic Ionic Liquids

“…Notably, next to an interface (solid-liquid, [30][31][32][33][34][35][36] air-liquid [37][38][39] or liquid-liquid [40,41] ), nanostructure closely related to, but more ordered than, the bulk phase is formed. This is because the second surface orients and aligns the pre-existing ion arrangement.…”

Surface of room temperature ionic liquid [bmim][PF6] studied by polarization- and experimental configuration-dependent sum frequency generation vibrational spectroscopy

“…The sample was filled in a round Teflon beaker (diameter 5 cm) which was cleaned in advance by first immersing in the Piranha solution for several hours, followed by rinsing with the ultrapure water obtained from the standard Millipore treatment (18.2 M cm). [15,37], respectively. As shown in Figure 2, the ppp spectra changed drastically when the incident angles were altered, whereas the ssp spectral line shapes were similar to each other for all the experimental configurations.…”