FREE-RADICAL OXIDATION OF ORGANIC PHOSPHONIC ACID SALTS IN WATER USING HYDROGEN-PEROXIDE, OXYGEN, AND ULTRAVIOLET-LIGHT

Photochemically initiated HO radical oxidations of 0.2-3.0 M isopropyl methylphosphonic acid (IPA) and methylphos-phonic acid (MPA) (as sodium salts) have been carried out at 25 °C in water solution using 0.01-3.0 M hydrogen peroxide and oxygen to effect complete oxidations of both compounds to phosphoric acid, carbon dioxide, and water. No intermediate oxidation products were found from oxidation of MPA, whereas acetone, acetic acid, and methylphosphonic acid were found in the oxidation of IPA. From the relative proportions of these intermediates, the relative and absolute rate constants for reactions of HO radical with IPA and MPA were calculated. The experiments suggest that rapid and complete oxidation of alkyl phosphorus compounds to simple products may be possible but careful control of reaction variables is necessary to achieve efficient use of H2O2. © 1979, American Chemical Society. All rights reserved.