Substituent Effect on the Electrochemical Oxidation of Trityl Anions. 2. Effect of an Electron-Withdrawing Group

The reversible one-electron oxidations of triarylmethyl anions and the irreversible second oxidative processes were examined for a series of sequentially substituted p-trimethylsilyl anions. The cycle voltammograms of the lithium salts prepared in dimethoxyethane reveal that the reversible potentials depend upon the substituent in the para positions. In contrast the second oxidative process is only slightly affected. Comparison with similarly substituted methyl triarylmethyl anions leads to estimates of the effect of a trimethylsilyl group on carbanion, radical, and cation stability.