Figure 5. The relationship between activation energy for the epoxidation of alkenes by peroxyl radicals and the difference between the ionisation energy of the alkene and the electron affinity of the peroxyl radical, (Ialkene - Aperoxyl). Acetylperoxyl (squares), methyperoxyl (circles), hydroperoxyl radicals (diagonal crosses), iso-propylperoxyl (horizontal lines) and tert-butylperoxyl radicals (triangles).