体积连接性指数预测离子液体的室温粘度

Estimation of the viscosity of ionic liquids at room temperature using volumetric connectivity index

离子液体(ILs)被视为潜在的"绿色溶剂",在溶剂的应用过程中粘度是最重要的热力学数据之一,但目前ILs的粘度数据仍然较为缺乏,除实验测定外,基团贡献、连接性指数等思想也为设计和筛选ILs提供了重要的性质预测方法。在已有的基于分子体积的粘度预测方法基础上,结合分子连接性指数来区分ILs不同基团的连接方式,建立了一个新的体积连接性指数模型用于预测ILs的室温粘度。由于该模型的基本参数来源于确定的基团物理体积值,因此为预测未知的ILs粘度等性质提供了可能性。通过对90种ILs室温粘度的预测,结果表明平均相对偏差为5.95%,方差检验所得的R^2和rmsd分别为0.9905和21cP,证明建立的模型可用于预测ILs的室温粘度。

Ionic Liquids （ILs） have been considered as good green replacements for conventional volatile organic solvents due to their uniqueenvironment-friendly characteristics. Viscosity data as one of the most important thermodynamic data needed for solvents are still in the scarcity for ILs. Although a large amount of experimental data have been measured and reported, some appropriate theoretical models that are crucial for the design and optimization of chemical processes are required to correlate and predict thermodynamic properties. In recent years,many efforts including group contribution and connectivity index were attributed to develop thermodynamic models to estimate the viscosity of ILs. In this article, a new approach named volumetric connectivity index （VCI） based on the physical observable volume of groups and the concept of molecular connectivity index was proposed for the prediction of the viscosity of ILs. Viscosities at room temperature of 90 pure ILs were estimated by this new model and the average devation was only 5.95%, R^2 and rmsd were 0.9905 and 21cP, respectively.