Radiolytically generated benzene triplets as sensitizers for energy and combined electron/proton transfer processes

Pulse radiolysis technique has been employed to investigate energy and elec tron transfer reactions involving triplets of naphthols and hydroxybiphenyl s. The transient absorption spectra obtained on pulse radiolysis of Nz satu rated solution of naphthols and hydroxybiphenyls in benzene are assigned to triplet-triplet absorption. It was found that biphenyl triplets undergo en ergy transfer to naphthols and hydroxy biphenyls forming the acceptor tripl ets. On the other hand, benzophenone triplets, favor electron transfer foll owed by Hf transfer reaction forming benzophenone ketyl radical and phenoxy l radical of the acceptor. An analogous sequence mimics with 2-naphthol tri plets and using benzophenone. acetophenone or chloranil as electron accepto r. (C) 2001 Elsevier Science B.V. All rights reserved.