Ionic-molecular composition of solutions of boron trifluoride with Lewis acids in oxygen-containing solvents

In nonprotogenic solvents boron trifluoride behaves as a Lewis acid that is close in strength to tin tetrachloride. The character of the ionic equilibria in ester solutions of boron trifluoride paired with other Lewis acids (halides of elements of Groups II-V) depends on the relative strengths of these acids. In solutions of boron trifluoride and stronger acids cationic forms of the two halides are formed in parallel; in the ionization of boron trifluoride simultaneously with a weak acid cations of the weaker acid and BF/sub 4//sup -/ anions are formed. A synergic action of two catalysts in nonprotogenic solvents occurs only in solutions of BF/sub 3/ together with a stronger acid. In protogenic solvents for processes catalyzed by hydrogen ions no synergic effect is observed.