Butyl methyl imidazolium cation based ionic liquids: Synthesis and characterization

Abstract

Four distinct ionic liquids based on 1-butyl-3-methylimidazolium (BMIM) were synthesized by using Br-, BF4-, PF6-, and HCO3- anions and their possible use as solvent in redox flow batteries were evaluated. The effectiveness of the synthesis process was evaluated by calculating the percentage yield, and the structure was deduced by the use of 1H, 13C, 31P, 11B, and 19F NMR. Formation of [BMIM]Br were confirmed by using ESI-MS/MS. The viscosity and ionic conductivities of the resulting ionic liquids were evaluated in acetone, nitromethane and ethanol as cosolvents. The results showed that the degree to which the ionic conductivity increased or decreased was dependent on the nature of the solvents. On the other hand, the temperature has an inverse connection with the viscosity of the ionic liquid. The appropriate ionic conductivity, ease of preparation, and low cost of the resulting ionic liquids all combine to make them an attractive option for use in electrochemistry and catalysis.