A triplet state path for adduct formation between benz[a]anthracene and the penta-1,3-dienes

Irradiation of benzene solutions of benz[a]-anthracene in the presence of either cis- or trans-penta-1,3-diene gives distinct sets of four products involving addition of C(7) and C(12) of benz[a]anthracene triplets to the C(1)–C(2) bond of the dienes.