ELECTRON-TRANSFER PROCESSES .19. REACTION OF ARYL RADICALS WITH ANIONS IN AQUEOUS-SOLUTION

Phenyl radicals and a variety of substituted phenyl radicals are readily trapped in aqueous solution by the anions of nitromethane, -ethane, or -propane to yield the radical anions which can be detected by ESR spectroscopy. Nitrite ion will also capture a variety of phenyl radicals in the absence of any heavy-metal ions. The p-nitropheny! radical can be trapped only by oxidation-resistant anions, such as nitrite or cyanide. The trapping of radicals by anions is greatly facilitated by the presence of a nitro group which will stabilize the resulting radical anion. In the absence of a trapping agent aryldiazonium ions and sodium dithionite form a variety of unstable paramagnetic species. © 1979, American Chemical Society. All rights reserved.