Application of Topological Index in Predicting Ionic Liquids Densities by the Quantitative Structure Property Relationship Method

Ionic liquids have attracted much attention in past decade for their unique properties. The density is an important property in industrial application, however the density data are relatively scarce compared with the great number of ILs. The quantitative structure property relationship (QSPR) and group contribution method (GCM) have been used for predicting ILs density. However, the accuracy of QSPR is not as good as that of GCM. In this work, a desirable QSPR model was developed to estimate ILs density. The general topological indexes (TIs) proposed by our research group were used to develop the QSPR model, which was on the basis of 5948 experimental data points for 188 ILs. The collected data are in the range of temperature (253.15–473.15) K and pressure (0.1–250) MPa. The correlation coefficient (R2) and the overall average absolute deviation are 0.998 and 0.422 %, respectively.