Unsaturation effect on the tunability of Ionic liquids.

Abstract

Three series of functionalized ion pairs composed of ethyl phenyl imidazolium [PhIM(C₂H₅)]⁺, (vinyl) ethenyl phenyl imidazolium [PhIM(C₂H₃)]⁺ and ethynyl phenyl imidazolium [PhIM(C₂H)]⁺ cations and acetate ([Y1]⁻), nitrate ([Y2]⁻), tetrafluoroborate ([Y3]⁻) and perchlorate ([Y4]⁻) anions were designed and their physical and chemical properties were analyzed at M06-2X-GD3/AUG-cc-pVDZ level of theory. The effect of alkyl chain unsaturation on structural characteristics, energetic parameters, electronic and topological properties, and the global reactivity parameters and also on some physical and chemical properties such as dipole moment, melting point, and electrochemical window of the introduced IPs was discussed. Based on electrochemical window values, the studied IPs including alkyl chain unsaturation in the cation and [Y1-2]⁻ anions have no suitable electrochemical stability for use in electrochemical devices.