Free-radical reductions of arenediazonium ions in aqueous solution. V. Pulse-radiolytic determination of rate constants for some para-substitutedbenzenediazonium ions

Abstract

Some rate constants for the reduction of para-substituted benzenediazonium ions by the radicals e_aq^-, ^·CH₂OH, (CH₃)2^·COH and some semiquinone radical anions have been measured. The substituent group has no effect on the rates with e_aq^-, but as the reduction potential of the reducing radical becomes more positive, the substituent effect increases, electron-withdrawing groups enhancing the rates. No free halide is formed on reduction of p-BrC₆H₄N₂⁺ or p-IC₆H₄N₂⁺ by e_aq^- or ^·CH₂OH.