School of Chemistry, University of Nottingham, Nottingham NG7 2RD, UK.
Phys Chem Chem Phys. 2010 Aug 21;12(31):8893-901. doi: 10.1039/c004197a. Epub 2010 Jun 9.
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.
使用视线质谱法（LOSMS）研究了离子液体（ILs）1-乙基-3-甲基咪唑双（三氟甲烷磺酰基）亚胺，[C（2）C（1）Im][Tf（2）N]和 1-乙基-3-甲基咪唑硫酸乙酯，[C（2）C（1）Im][EtOSO（3）]的蒸气相可以被检测到的温度。通过优化先前实验中使用的检测系统，对于[C（2）C（1）Im][Tf（2）N]，可以检测到蒸气的最低温度约为 340 K，而对于[C（2）C（1）Im][EtOSO（3）]，则约为 390 K。初步研究还表明，测量温度会影响 298 K 时的汽化焓，Delta（vap）H（298）。讨论了这些与温度有关的 Delta（vap）H（298）差异的原因。这两种 IL 的蒸气压都比以前达到的温度低得多，并给出了室温下的外推值。
