Predicting the glass transition temperature of ionic liquids by the quantitative structure property relationship method using a topological index

• A general topological index was proposed based on atom characters and position.
• A QSPR model was developed to predict the glass transition temperatures of ILs.
• A topological index was generated from anion and cation.

:Based on the general topological index (TI) proposed in our previous work, a Quantitative Structure–Property Relationship (QSPR) model was developed to predict the glass transition temperatures of ionic liquids (ILs). Because ILs are a class of molten salts which are composed entirely of cations and anions, in general, the descriptors for ILs are calculated from cations and anions separately and the interaction between them is neglected. In this study, except the two sets of TIs generated from cation and anion, a third TI was used to depict the interaction of anion and cation. The QSPR model is based on five kinds of ILs, which are imidazolium (Im), pyridinium (Py), ammonium (Am), sulfonium (Su), triazolium (Tr). The regression coefficient (R2) and the overall average absolute relative deviation (AARD) are 0.894 and 3.32%, respectively.