Characterisation and properties of new ionic liquids with the difluoromono[1,2-oxalato(2-)-O,O′]borate anion

Three ionic liquids with borate anions of low symmetry, tetraethylammonium difluoromono[1,2-oxalato(2-)-O,O′]borate, 1-ethyl-3-methylimidazolium difluoromono[1,2-oxalato(2-)-O,O′]borate, and 1-butyl-3-methylimidazolium difluoromono[1,2-oxalato(2-)-O,O′]borate were synthesised and characterised by physicochemical and electrochemical measurements including thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), cyclic voltammetry (CV), viscosity and conductivity measurements.

Substitution of the [BF4]− anion by [BF2Ox]− in [NEt4]+ salts leads to a significant decrease of the melting point proving that ionic liquids can be also based on reduced symmetry of the anion even if the cation is highly symmetrical. Figure optionsDownload as PowerPoint slide