Predicting the surface tensions of ionic liquids by the quantitative structure property relationship method using a topological index

Abstract

The general topological indexes (TIs) proposed in our previous work were applied to predict the surface tensions of ionic liquids (ILs) by Quantitative Structure Property Relationship (QSPR) method. ILs are a class of molten salts which are composed entirely of cations and anions, therefore the descriptors for ILs are generally calculated from cations and anions separately and the interaction between them is always neglected. In this study, besides the two sets of TIs generated from cation and anion, a third TI was used to depict the interaction of anion and cation. Differing from the previous estimation methods for surface tensions of ILs, the temperature dependence is also correlated by structure parameters. 930 surface tension data points for 115 ILs are applied to develop QSPR model. The correlation coefficient (R2) and the overall average absolute deviation (AAD) are 0.9516 and 3.43%, respectively.