Photochemical α-cleavage and hydrogen abstraction in deoxybenzoin: a laser spectroscopy investigation

Publisher Website
Google Scholar
Abstract
Transient absorptions in the range 380–500 nm in deoxybenzoin are investigated for the first time by nanosecond laser spectroscopy. This study gives evidence for absorption by a triplet state, and by benzoyl and benzyl radicals. Photoreduction of the triplet state and generation of a ketyl radical are also obtained. This enables some peculiar results of the polymerization of vinyl monomers photoinduced by deoxybenzoin to be explained. Our results show that deoxybenzoin exhibits a peculiar behaviour since the two photoprocesses occur with the same efficiency. Hydrogen abstraction and α-cleavage rate constants, quenching rate constants of the species by oxygen, lifetimes of the transients, and absorption spectra are derived. The influence of the solvent is discussed as a function of the excited states involved. A complete diagram of the evolution of the energy levels is thus obtained.

This publication has 0 references indexed in Scilit: