Free radicals derived from benzo[a]pyrene.

At least four different free radicals can be formed from benzoa]pyrene under different reaction conditions, namely the 6-oxybenzoa]pyrene radical, the benzoa]pyrene anion and cation radicals and a radical from heated benzoa]pyrene. The formation and esr spectra of these radicals have been studied with the aim of clarifying the nature of the radical species involved under different reaction conditions. Additionally the reactivity of the 6-oxybenzoa]pyrene and the benzoa]pyrene cation radicals towards several phenolic antioxidants have also been investigated.