Formation of Radical Anions in the Reaction of <i>p</i>-Benzoquinone and C₆₀ with Alkoxide Ions

Abstract

Reactions of p-benzoquinone and its derivatives with hydroxide and alkoxide ions (RO-: R = H, Me, Et, i-Pr, PhCH2) in acetonitrile (MeCN) result in formation of the corresponding semiquinone radical anions accompanied by the formation of RO-substituted p-benzoquinones, which are the oxidized products of p-benzoquinones. Detailed product and kinetic analyses of the reactions have demonstrated that the RO-adduct anion of p-benzoquinone is a real electron donor and that RO- is acting as a very strong base or nucleophile rather than a one-electron reductant in an aprotic solvent, such as MeCN. Similarly, the reaction of C60 with methoxide anion (MeO-) in benzonitrile (PhCN) results in formation of C60•-. Spectroscopic and kinetic studies also indicate that a methoxy adduct anion of C60 is an actual electron donor and that MeO- is acting as a very strong base or nucleophile rather than an electron donor in PhCN.