Kelkar Manish S, Maginn Edward J
J Phys Chem B. 2007 Aug 16;111(32):9424-7. doi: 10.1021/jp073253o. Epub 2007 Jul 20.
Classical atomistic simulations are used to compute the enthalpy of vaporization of a series of ionic liquids composed of 1-alkyl-3-methylimidazolium cations paired with the bis(trifluoromethylsulfonyl)imide anion. The calculations show that the enthalpy of vaporization is lowest for neutral ion pairs. The enthalpy of vaporization increases by about 40 kJ/mol with the addition of each ion pair to the vaporizing cluster. Non-neutral clusters have much higher vaporization enthalpies than their neutral counterparts and thus are not expected to make up a significant fraction of volatile species. The enthalpy of vaporization increases slightly as the cation alkyl chain length increases and as temperature decreases. The calculated vaporization enthalpies are consistent with two sets of recent experimental measurements as well as with previous atomistic simulations.
经典原子模拟用于计算一系列由1-烷基-3-甲基咪唑鎓阳离子与双（三氟甲基磺酰）亚胺阴离子配对组成的离子液体的汽化焓。计算结果表明，中性离子对的汽化焓最低。随着每个离子对添加到汽化团簇中，汽化焓增加约40 kJ/mol。非中性团簇的汽化焓比其对应的中性团簇高得多，因此预计不会构成挥发性物种的很大一部分。随着阳离子烷基链长度的增加和温度的降低，汽化焓略有增加。计算得到的汽化焓与最近的两组实验测量结果以及先前的原子模拟结果一致。
