The electroreduction of acrylonitrile: A new insight into the mechanism - Comments

According to Mertens et al., polyacrylonitrile (PAN) is selectively electrografted onto nickel at less cathodic of two reduction potentials of acrylonitrile (AN) as a result of the formation of (AN) radicals which are firmly linked to cathode and propagate radical polymerization of AN. Anionic mechanisms can be rejected on the basis of 3 new experimental results: peak 1 behavior as a function of scan rate identifies the process as a one-electron transfer; peak 1 voltammetric characteristics are modified when diphenylpicrylhydrazyl (DPPH) is added; but are not modified when ε-caprolactone (ε-CL) is added. When a radical mechanism is forwarded unresolvable contradictions arise, but these contradictions are absent when an anionic mechanism is assumed.