Vaporisation of an ionic liquid near room temperature

Abstract

The temperature at which the vapour phase of the ionic liquids (ILs) 1-ethyl-3-methylimidazolium bis[(trifluoromethane)sulfonyl]imide, [C(2)C(1)Im][Tf(2)N], and 1-ethyl-3-methylimidazolium ethylsulfate, [C(2)C(1)Im][EtOSO(3)], can be detected was investigated using line-of-sight mass spectrometry (LOSMS). By optimising the detection system used in previous experiments, the lowest temperature for which vapour was detected for [C(2)C(1)Im][Tf(2)N] was approximately 340 K, whereas for [C(2)C(1)Im][EtOSO(3)] it was approximately 390 K. Initial investigations also show that the temperature at which measurements are made affects the enthalpy of vaporisation at 298 K, Delta(vap)H(298). The reasons for these differences in Delta(vap)H(298) with respect to temperature are discussed. The vapour pressure of both ILs is estimated at far lower temperatures than previously achieved and extrapolations to room temperature are given.

Surface Science and Model Catalysis with Ionic Liquid‐Modified Materials

“…Recently we have described a bakeable PVD source, which can be fi lled and refi lled in-situ without breaking the UHV environment. [ 54 ] In the meantime, numerous ILs have been vaporized [ 59 ] and vapor pressures of some aprotic ILs have been measured. [61][62][63] So far, most of these studies have been performed at elevated temperatures, typically above 400 K. Recently, Lovelock et 6 ], for instance, both molecular vaporization [ 58 ] and decomposition [ 64 ] has been reported.…”

Environmental safety of cholinium-based ionic liquids: assessing structure–ecotoxicity relationships

“…3 ), making them unlikely atmospheric pollutants. However, their ionic character makes most of them soluble in water 4,5 , which can translate into an environmental problem if they happen to be toxic to the organisms inhabiting aquatic ecosystems.…”

Vaporization enthalpies of imidazolium based ionic liquids. A thermogravimetric study of the alkyl chain length dependence

“…Vaporization enthalpies for a series of ten ionic liquids (ILs) 1-alkyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide [C n mim][NTf 2 ], with the alkyl chain length n = 4, 6,8,10,12,14,16, and 18 were determined using the thermogravimetric method. An internally consistent set of experimental data and vaporization enthalpies at 540 K was obtained.…”