Novel Photochemical Reactions of C8H10 Radical Cations

Article abstract of DOI:10.1021/j100184a033

The radical cation of bicyclo<2.2.2>octa-2,5-diene produced in a γ-irradiated Freon matrix at 77 K shows a broad charge-resonance absorption band with λ_max = 680 nm.In contrast to earlier experiments in argon matrices, it was found that the primary photoreaction of this species is a cleavage to yield the recently described complex cation between benzene and ethylene whose λ_max happens to coincide with that of the above precursor cation.This complex cation can in turn be converted eventually to 1,3,5,7-octatetraene radical cation.In the presence of an excess of ethylene, the above complex cation undergoes a photoaddition yielding a C10H14^.+ whose spectrum indicates the presence of a linear conjugated triene chromophore.The electronic structure of the different radical cations involved in this study is discussed and a reaction scheme is proposed.