Generation and stability of superoxide ion in tris(pentafluoroethyl)trifluorophosphate anion-based ionic liquids

Abstract

Generation of the superoxide ion (O2−) in ionic liquids (ILs) media is one of the important areas which are currently being under investigation by several research groups worldwide. In this work, the superoxide ion was successfully generated and analyzed electrochemically using cyclic voltammetry (CV) and chronoamperometry (CA) techniques from O2 dissolved in 1-(2-methoxyethyl)-1-methylpiperidinium tris(pentafluoroethyl)trifluorophosphate [MOEMPip][TPTP] and trihexyl(tetradecyl)phosphonium tris(pentafluoroethyl)trifluorophosphate [P14,666][TPTP]. Furthermore, O2− was generated chemically by the addition of potassium superoxide to the studied ILs. UV/Vis spectrophotometer was used for testing the long term stability of the generated O2−. These results encourage more exploration on the use of these particular classes of ILs in various applications involving O2−. This study reports the first successful chemical generation of O2− in tris(pentafluoroethyl)trifluorophosphate anion-based ILs which opens the way for further related studies.