Radical cations of DPBEY and PPCB were generated by g-radiolysis and pulse radiolysis in halogenated solvents.
The radical cation PPCB·+ shows 505 (shoulder) and 520 nm absorption peaks with 700 ns lifetime in agreement with the laser flash photolysis work and strongly support the exciplex mechanism proposed for the photoreaction of PPCB and dimethylfumarate.