Novel electrolyte salts based on perfluoroalkyltrifluoroborate anions: 1. Synthesis and characterization

Lithium and tetraethylammonium perfluoroalkyltrifluoroborate salts, Li[RfBF3]·H2O and Et4N[RfBF3] (Rf=C2F5, n-C3F7 and n-C4F9), were prepared from the reactions of perfluoroalkylmagnesium reagents (RfMgBr) and B(OCH3)3, followed by fluorination by aq.KHF2 and aq.HF solutions and the cation exchange reaction of the resultant K[RfBF3]. All the salts prepared were characterized by 19F NMR, 1H NMR, 11B NMR, 7Li NMR, IR, MS and elemental analysis.