New imidazolium ILs with nitrile functionality and ether group were synthesized. Thermo physical properties were measured in a wide temperature range. The dual functionalized imidazolium ILs showed thermal stability up to 300 °C. Refractive index and molar polarizability correlated by Lorentz-Lorentz equation. COSMO-RS used to predict their application in desulfurization of fuel.