Electrochemistry of 1-butyl-3-methyl-1H-imidazolium tetrafluoroborate ionic liquid

The electrochemistry of 1-butyl-3-methyl-1H-imidazolium tetrafluoroborate (BmimBF(4)) ionic liquid was investigated by cyclic voltammetry and Osteryoung square wave voltammetry. Impurity chloride was identified, its concentration was determined and a way to eliminate it was demonstrated. Constant current electrolysis of BmimBF4 was performed and products were analyzed by H-1, C-13, and F-19-NMR and gas chromatography-mass spectrometry. BF3 and fluorocarbons are produced at the anode while Bmim(+) undergoes dimerization and dealkylation reactions at the cathode after reduction to a carbene. (C) 2003 The Electrochemical Society.