Synthesis and characterization of the first examples of perfluroalkyl-substituted trialkyloxonium salts, [(CH(sub)3)(sub)2OCF(sub)3](sup)+[Sb(sub)2F(sub)11](sup)- and [CH(sub)3)(sub)2OCF(CF(sub)3)(sub)2](sup)+[Sb(sub)2F(sub)11](sup)-

This article describes the synthesis of some new perfluoro-alkyl-substituted tertiary oxonium ions and the effect of perfluoroalkyl substitution in the structure of the ions. Data show that replacement of one methyl group with trifluoromethyl group enhances the O-CH(sub)3 bond lengths by 0.037 angstrom and the sum of the C-O-C bond angles by approximately 4.5 degrees.