ABSTRACT
Autoxidation of organic compounds occurs as an autoinitiated process where hydroperoxides
are the major source of free radicals (see Chapter 6). This fact determines the kinetic pattern
of autoxidation, whose rate is proportional to either [ROOH]1/2 or [ROOH], depending on
the mechanism of chain initiation and termination. One can anticipate that autoxidation can
be affected by factors influencing the concentration and decay of hydroperoxides. It should be
taken into account here that hydroperoxide can decompose either homolytically or hetero-
lytically. In the former case, the resulting free radicals accelerate oxidation (see Chapter 6).
On the other hand, the heterolytic decomposition of hydroperoxide into molecular products
(the so-called molecular decomposition) decreases the concentration of hydroperoxide and,
hence, reduces the rate of autoinitiation (see Chapter 10). Namely, heterolytic decomposers of
hydroperoxides can retard the autoxidation of organic compounds. Since as hydroperoxides
are oxidizing reactants the substances with reducing activity should be good hydroper-
oxide decomposers. Among them, phosphorus and sulfur compounds are used as antioxi-
dants of organic compounds. The detailed kinetic study of their action evidenced that they
are antioxidants of a complex mechanism of inhibiting action. They react with hydroper-
oxide, as well as with peroxyl radicals, and, in addition, produce products with antioxidant
properties.
