Investigation of the effects of cation/anion structure in ionic liquids for extractive desulfurization: QSPR approach

In the present research the best structural descriptors for different cation and anion were investigated using quantitative structure−property relationship (QSPR) approach to find proper ionic liquid (IL) for extractive desulfurization. Five different datasets were collected from the literature containing{(Cation/[NTf2]−thiophene−n-heptane),(Cation/[NTf2]−thiophene−n-hexane),(Cation/[FAP]−thiophene−n-heptane),(Cation/[TCM]−thiophene−n-heptane),([C2MIM]/Anion−thiophene−hydrocarbon),([C8MIM]/Anion–thiophene−hydrocarbon)}. By investigating the various kinds of molecular descriptors, it was found that the increment of Spanning Tree Number (STN) descriptor as cation structure descriptor, causes a decrease in mole fraction of thiophene in IL-rich phase due to the increase in steric hindrance. Also, it was found that an increase in E1p which represents the density of atoms projected along the length or unfilled space of the anion value as anion structure descriptor leads to the decrement of mole fraction of thiophene in the IL-rich phase