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1.Oxygen, water, and phenoxyl radicals are the key products which determine the contribution of free-radical processes to the reaction of ozone with phenols.2.Comparison of the reaction kinetics with reaction products suggests that the principal reaction path is that in which ozone is captured by the hydroxyl group of the phenol and then penetrates into the aromatic ring.

1.Ozone reacts with phenol in aqueous solution, attacking the phenol group and opening the aromatic ring.2.The reaction follows a bimolecular rate law over the entire range of ozone and phenol concentrations.3.The Arrhenius parameters for reaction in water are anomalously high in comparison with the parameters for this same reaction in nonaqueous solution.

1.A study has been made of the effect on the hydroxyl ion concentration of the rate of ozone breakdown in aqueous solution.2.The limiting stage in this reaction is the bimolecular transfer of an electron from the hydroxyl ion to the ozone molecule.3.A kinetic description of this process has been given and rate constants for the O3-OH reaction calculated at four different temperatures.

The kinetics of the reaction of O3 with PhOH in alkaline medium has been studied. The rate of oxidation of phenol by ozone is directly proportional to the concentrations of reactants and increases in a complex manner with increase in alkali content in aqueous solution. The composition of the reaction products was investigated and it was found that dimers and oligomers of phenoxyl radicals predominate in alkaline medium. A mechanism is proposed for the process.

An investigation has been carried out into the composition of the products of the O3 reaction with PhOH in different solvents and into the kinetics of their build-up. A scheme is proposed for the reaction in which the first stage, which limits the rate of the entire process, is formation of a complex of O3 with the PhOH hydroxy group. Formation of muconic acid does not require the participation of H2O.

The reaction of ozone with 3,6-di-tert-butylpyrocatechol at ~20°C was investigated, and it was found that the main reaction product was 3,6-di-tert-butylquinone, while the reaction rate was proportional to the concentrations of the reagents. A reaction scheme explaining the mechanism of formation of the main and side products is proposed.

It was shown that two series of products with opening and with preservation of the aromatic nucleus are formed in the reaction of ozone with ionol, and a mechanism was proposed for the reaction.

1.Comparative data were obtained on the reaction rates of phenol with ozone in CCl4 and in water.2.The experimental data show that in the elementary reaction act the ozone molecule approaches the phenol molecule perpendicular to the direction of the O-H bond.

1.The nature of the free radicals formed in the reaction of ozone with 2,4,6-tri-tert-butylphenol was studied and their amount was determined. The phenoxyl radical was detected in solution when the conversion is incomplete, while peroxide radicals appear in the system when the phenol conversion is complete.2.A comparison of the stoichiometry of the reaction with the relative amount of the phenoxyl radical discloses that the cleavage of hydrogen from the hydroxy group to give the phenoxyl radical is a secondary process.