Radical cations generated by photo-induced electron transfer in solution or by chemical oxidation in the channels of a redox-active zeolite (NaZSM-5) may be deprotonated, giving rise to neutral radicals. In solution, the geminate radical anion or an added nucleophile (methanol) may serve as the proton acceptor. Deprotonations in solution are not efficient; the corresponding products may be suppressed by several competing intra- or bi-molecular reactions. Although methanol serves as the base deprotonating at least one radical cation, it often is more efficient as a nucleophile, thereby depressing deprotonation. Deprotonations in the zeolite are more effective, presumably, because competing reactions with outside reagents are precluded. Occasionally, NaZSM-5 zeolites promote complex reaction sequences, such as the conversion of p-propylanisole to the radical cation of anethole or the deprotonation-ring opening of 1,2-diphenylcyclopropane radical cation to exo,exo-diphenylallyl radical.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)