These results are consistent with a one-electron oxidation of PCBA to the amine radical cation followed by homolytic cyclobutane ring cleavage.

The exothermicity of the reaction correlates well with the ability of the substituent to stabilize the 1,3-butadiene radical cation by electron donation or conjugation.

Spectroscopic studies indicated that these radical cations and dications have good stability.

Ready generation of radical cations was supported by cyclic voltammetry measurements, revealing stepwise formation of radical cation and dication species in solution.