McDaniel Jesse G, Choi Eunsong, Son Chang Yun, Schmidt J R, Yethiraj Arun
Department of Chemistry and ‡Department of Physics, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
J Phys Chem B. 2016 Jul 21;120(28):7024-36. doi: 10.1021/acs.jpcb.6b05328. Epub 2016 Jul 12.
We develop ab initio force fields for alkylimidazolium-based ionic liquids (ILs) that predict the density, heats of vaporization, diffusion, and conductivity that are in semiquantitative agreement with experimental data. These predictions are useful in light of the scarcity of and sometimes inconsistency in experimental heats of vaporization and diffusion coefficients. We illuminate physical trends in the liquid cohesive energy with cation chain length and anion. These trends are different than those based on the experimental heats of vaporization. Molecular dynamics prediction of the room temperature dynamics of such ILs is more difficult than is generally realized in the literature due to large statistical uncertainties and sensitivity to subtle force field details. We believe that our developed force fields will be useful for correctly determining the physics responsible for the structure/property relationships in neat ILs.
我们从头开始开发了基于烷基咪唑鎓的离子液体（ILs）的力场，该力场预测的密度、汽化热、扩散和电导率与实验数据达成了半定量一致。鉴于实验汽化热和扩散系数的稀缺性以及有时存在的不一致性，这些预测很有用。我们阐明了液体内聚能随阳离子链长和阴离子的物理趋势。这些趋势与基于实验汽化热的趋势不同。由于存在较大的统计不确定性以及对细微力场细节的敏感性，此类离子液体室温动力学的分子动力学预测比文献中普遍认识到的更困难。我们相信，我们开发的力场将有助于正确确定纯离子液体中结构/性质关系背后的物理原理。
