Autoxidation

AUTOXIDATION (from the Greek autos-self and oxys-sour), self-oxidation, processes of spontaneous attachment of molecular O to substances capable of oxidation, occurring without the introduction of free energy from outside. The simplest process of this kind is the oxidation of alkali metals, phosphorus, etc. The participation of O in these processes can be conceived, according to Bach and Engler, in such a way that in the O molecule the double bond breaks and the group -O--, possessing two free valences, enters into reaction. For example, in the case of oxidation of H, hydrogen peroxide H-O-O-H is first formed, which then, with the participation of the next H molecule, gives water: H₂+O₂=H₂O₂; H₂O₂+H₂=2H₂O. In a similar way, peroxides analogous to hydrogen peroxide are formed as the primary product of oxidation whenever an unsaturated body comes into contact with molecular O. In some cases, it is possible to quantitatively isolate the intermediate peroxides that form. Such a case occurs in the oxidation of triphenylmethyl: (C₆H₅)₃C-O (C₆H₅)₃C-O₂(C₆H₅)₃C⁺O₂(C₆H₅). Peroxides are oxidizing agents, since they contain one O atom in a weakly bound state and easily give it up to other bodies capable of oxidation. The so-called "ozone-treated" turpentine used in certain reactions (e.g., in the blood test) owes its oxidizing properties to the peroxides formed in it under the action of atmospheric O.