Photochemical Transformations. 30. Photosolvolysis of Benzyl Chlorides in tert-Butyl Alcohol. 2. Nature of Excited States

Article abstract of DOI:10.1021/ja00414a041

The photosolvolysis of a number of benzyl chlorides in tert-butyl alcohol, both as a result of direct irradiation and ketone triplet sensitization, has been studied.A variety of sensitization and quenching techniques have been used.The results obtained are rationalized by the assumption that there are two triplet states of the benzyl chlorides accessible in these experiments - one a short-lived upper state, which leads to solvolysis product, and another a long-lived (lower energy) state, which reverts to ground-state reactant.Consistent with this idea, m-methoxybenzyl chloride is shown to quench the photoreactions of benzopenone with benzhydrol without the formation of a significant amount of reactive species.The effects of wavelength on the reactions of p-acetobenzyl chloride are mesured and discussed in terms of the two-triplet concept.