Stability and Kinetics of Generated Superoxide Ion in Trifluoromethanesulfonate Anion-Based Ionic Liquids

摘要

- The generation and long-term stability of superoxide ion (O2 ) in two trifluoromethanesulfonate [TfO]+ anion-based ionic liquids (ILs), with cations of 1-butyl-1-methylpyrrolidinium [BMPyrr] and 1-butyl- + 2,3-dimethylimidazolium [BDMIm] have been investigated. The electrochemical generation was carried out by reducing O2 to O2 in ILs and was analyzed using a cyclic voltammetry (CV) technique. The chemical generation of O2 in ILs was carried out by the solvation of potassium superoxide (KO2)in the aprotic solvent, dimethyl sulfoxide, in the presence of the corresponding IL. Long-term stabilityof generated O2 in ILs was examined using UV-visible spectrophotometery at an absorbance range of+ 19000 nm. It was found that the [BMPyrr] based IL has a lower O2 consumption rate than the+ [BDMIm] based ILs indicating that [BMPyrr][TfO] offers a promising long-term stability of O2 for- various reactions and applications. This work represents the first attempt for using the [TfO] based ILs as media for the chemical and electrochemical generation of O2 .