The aerobic oxidation of unsaturated fatty acids and their esters: cobalt stearate-catalyzed oxidation of linoleic acid.

The connection between metal catalysis and the initiation step in autoxidation is emphasized. The formation of free radicals occurs in reactions involving not only various valency states, but also oxygen-complexes of the catalyst. The kinetics of the initial phase of the metal-catalyzed aerobic oxidation of linoleic acid are examined in detail, and a number of mechanisms postulated. The rate constants for certain initiation reactions are evaluated together with the corresponding activatian energies. The observed values are found to be in fair agreement with theoretical considerations and, in general, the evidence lends further support to the hypothesis that trace-metal catalysis and the initiation of autoxidation are intimately connected.