Polarography of organic cations in acid solutions. Part 3. Three 1,1-diarylethyl ions in sulphuric and methanesulphonic acids

Abstract

The u.v. spectra and polarography of the 1,1-bis-(2,4-dimethylphenyl)ethyl (1) and 1,1-di-o-tolylethyl (2) carbenium ions in 15M-H₂SO₄ and in anhydrous and aqueous MeSO₃H have been investigated. The reductions are irreversible and can be interpreted by the reaction scheme proposed previously. An explanation is suggested why a spectrum but no reduction wave could be found for the 1,1-bis-(2-methyl-4-chlorophenyl)ethyl ion (3). Our present and earlier E_½ values for carbenium ions in acids are presented on a scale based on the trityl cation; this provides a convenient reference potential for media in which ferrocene breaks down.