Influence of Anion on Physical and Electronic Property of Imidazolium Ionic Liquids: Role of Weak Interactions

Abstract

In present work, role of weak interactions on physical property of newly synthesized 2,4‐Dinitrophenolate (DNP) anion‐based imidazolium room temperature ionic liquids (RTILs) has been investigated for understanding effect of small structural change in anion. Aromatic and aliphatic H‐bonding interaction do not play significant role on physical properties of these RTILs. But weak π‐π stacking interaction plays an important role to determine the physical properties of these RTILs. The DNP anion shows unique characteristic intramolecular charge transfer (ICT) process due to presence of its quinoid structure in solution. Quinoid structure of DNP anion in these RTILs does not allow to form strong intermolecular ion‐pair cluster through π‐π stacking interaction. As intermolecular interactions are very less, DNP based RTILs are liquids at room temperature. Tuning electronic and physical properties of these yellow coloured DNP based RTILs are raised only from DNP anion.