Electron-transfer process with pyridinium, quinolinium, and pyrazinium salts; an electron spin resonance study

Electron-transfer processes between nucleophilic neutral and charged free-radicals [hydroxy(diphenyl)methyl and naphthalene radical anion] and pyridinium, quinolinium, and pyrazinium salts have been investigated by e.s.r. The factors affecting the persistence of the heterocyclic radicals under photolytic conditions are discussed. Mechanistic implications concerning the reactions of nucleophilic free radicals with protonated heteroaromatic bases are emphasized.