Photochemical studies on the ethyl radical

Photochemical studies are performed on dipropionyl peroxide and the ethyl radical in argon matrices. Matrix isolated dipropionyl peroxide photochemically produces the ethyl radical upon exposure to ultraviolet light in the λ≳2800 Å region. Irradiation of the ethyl radical by UV light with λ<2800 Å produces ethyl propionate, propionic acid, ethylene, and acetylene. The first three products are formed at a rate different from that for formation of acetylene. This different rate dependence is conveniently explained in terms of a site dependence for the photochemistry.