Albert-Ludwigs-Universität Freiburg, Institut für Anorganische und Allgemeine Chemie, Freiburg, Germany.
Chemphyschem. 2011 Aug 22;12(12):2296-310. doi: 10.1002/cphc.201100214. Epub 2011 Jul 12.
A series of bis(trifluoromethylsulfonyl)imide ionic liquids (ILs) with classical as well as mildly functionalized cations was prepared and their viscosities and conductivities were determined as a function of the temperature. Both were analyzed with respect to Arrhenius, Litovitz and Vogel-Fulcher-Tammann (VFT) behaviors, as well as in the context of their molecular volume (V(m)). Their viscosity and conductivity are highly correlated with V(m)/T or related expressions (R(2) ≥0.94). With the knowledge of V(m) of new cations, these correlations allow the temperature-dependent prediction of the viscosity and conductivity of hitherto unknown, non- or mildly functionalized ILs with low error bars (0.05 and 0.04 log units, respectively). The influence of the cation structure and mild functionalization on the physical properties was studied with systematically altered cations, in which V(m) remained similar. The T(o) parameter obtained from the VFT fits was compared to the experimental glass temperature (T(g)) and the T(g)/T(o) ratio for each IL was calculated using both experimental values and Angell's relationship. With Walden plots we investigated the IL ionicity and interpreted it in relation to the cation effects on the physical IL properties. We checked the validity of these V(m)/T relations by also including the recently published variable temperature viscosity and conductivity data of the Al(OR(F))(4) ILs with R(F) =C(H)(CF(3))(2) (error bars for the prediction: 0.09 and 0.10 log units, respectively).
一系列具有经典阳离子和轻度官能化阳离子的双（三氟甲基磺酰基）酰亚胺离子液体（ILs）被制备，并确定了它们的粘度和电导率随温度的变化。这两个参数都分别通过阿累尼乌斯、利托维茨和沃格-富勒-坦曼（VFT）行为以及它们的分子体积（V(m)）进行了分析。它们的粘度和电导率与 V(m)/T 或相关表达式（R(2)≥0.94）高度相关。通过对新阳离子的 V(m)的了解，这些相关性允许根据 V(m)来预测未知的、非官能化或轻度官能化的 IL 的温度依赖性粘度和电导率，误差较小（分别为 0.05 和 0.04 对数单位）。通过系统改变阳离子结构和轻度官能化，研究了阳离子结构和轻度官能化对物理性质的影响，其中 V(m)保持相似。从 VFT 拟合中获得的 T(o)参数与实验玻璃化温度（T(g)）进行了比较，并且使用实验值和安格尔关系计算了每个 IL 的 T(g)/T(o)比值。通过沃尔登图，我们研究了 IL 的离子性，并将其与阳离子对 IL 物理性质的影响联系起来进行解释。我们通过还包括最近发表的 Al(OR(F))(4) ILs 的可变温度粘度和电导率数据（R(F)=C(H)(CF(3))(2)，预测误差分别为 0.09 和 0.10 对数单位）来检查这些 V(m)/T 关系的有效性。
