Photochemical hydrogen abstractions as radiationless transitions. Part 2.—Thioketones, quinones, aza-aromatics, olefins and azobenzenes

Abstract

The hydrogen abstraction reactions of triplet states of thioketones, quinones, aza-aromatic compounds, olefins and azobenzenes have been studied theoretically as radiationless transitions in terms of the tunnel-effect theory. Good agreement with experiment is found and rates of reaction are predicted for several systems which have not yet been studied experimentally. Although in general n,π* states are more reactive than π,π* states, the theory reveals cases where π,π* reactivity, which is strongly dependent on bond length changes between reactants and products, can be higher than n,π* reactivity.