LAUSR

In this study, the quantum chemical descriptors such as highest occupied molecular orbital (HOMO) energy, lowest unoccupied molecular orbital (LUMO) energy, HOMO‐LUMO energy gap, electrophilicity index, electronegativity, global hardness and global softness of five cations like 1‐butyl‐3‐methylimidazolium [BMIM]+, 1‐pentyl‐3‐methylimidazolium [PMIM]+, 1‐hexyl‐3‐methylimidazolium [HMIM]+, 1‐heptyl‐3‐methylimidazolium [HEPMIM]+ and 1‐octyl‐3‐methylimidazolium [OMIM]+ and five anions including butyl sulfate [BUSO4]−, pentyl sulfate [PENSO4]−, hexyl sulfate [HEXSO4]−, heptyl sulfate [HEPSO4]−, and octyl sulfate [OCTSO4]− and their combination of 25 ionic liquids (ILs) were predicted using ab initio method. To validate the findings, the sigma profiles and sigma potentials were generated for all the studied ILs. From this study, it was observed that imidazolium‐based ILs with smaller anion size is the most favorable IL for the removal of pollutants from their resources and/or effluents. © 2020 Wiley Periodicals, Inc.