Fourier-transform IR and NMR spectroscopy are used to show that, in the reaction with 2,2'‑diphenyl-1-picrylhydrazyl radical, the secondary products of natural phenol conversion are dimeric compounds formed by recombination of phenoxyl radicals. According to thermodynamic parameters of the reaction calculated by the DFT method the most stable structures in the studied system are CC dimers. The resulting dimeric phenols show a lowered antiradical activity compared to the original phenol, which ensures a prolonged effect of the original antioxidant and enhances its overall antioxidant activity in radical oxidation reactions.

Kinetics and mechanism of the reaction of vegetable phenols (PhOH) with 2,2′-diphenyl-1-picrylhydrazyl radical (DPPH•) in a polar aprotic solvent, dimethyl sulfoxide, were studied. The reaction of natural phenols with DPPH• in dimethyl sulfoxide occurs in two stages. In the first stage, a proton-coupled electron transfer (PCET) occurs from a PhOH molecule to DPPH• to give primary transformation products, phenoxyl radicals (PhO•) and diphenyl hydrazine (DPPH–H), and in the second, the hydrazyl radical is consumed in the reaction with PhO• transformation products, enolized dimers, which is confirmed by NMR spectroscopy. A relationship was revealed between the antiradical activity of phenols in the reaction with DPPH• (ln k) and the ionization potential of the phenolates being formed.

The activation parameters of the reactions between a superoxide anion (O 2 ·− ) and alkyl bromides are measured. An ab initio study of the transition states for various mechanisms of this reaction is performed. The mechanism of radical separation in a polar solvent becomes competitive upon an increase in the number of alkyl groups in an alkyl bromide molecule and depends on their arrangement relative to a reaction center.

Initiated oxidation of cumene with oxygen in the presence of various phenol antioxidants and a supramolecular system containing the oxygen radical anion of was studied. It is shown that superoxide anion and ionol, hydroquinone, and ethyl gallate are the antagonists in the process of inhibition of the radical chain oxidation. Simultaneous introduction of the ascorbic acid and the radical anion of oxygen caused the synergistic effect.

The radical-chain oxidation of cumene initiated by azodiisobutyronitrile in the presence of oxygen radical anions was studied. The source of O-2(-.) was the KO2-18-crown-6 system. The observed inhibiting effect was explained by one-electron transfer from the anion to the peroxy radical.

Formation of O 2 - -containing supramolecules generated from the system 18-crown-6-KO 2 and electrochemically (tetraethylammonium superoxide) and the kinetics of the reactions of the generated O 2 - with alkyl halides in acetonitrile were studied conductometrically and UV-spectrophotometrically; the kinetic parameters of the processes were determined. The E 2 mechanism was suggested for the reaction.

The ability of the benzoyl peroxide–potassium bromide–18-crown-6 system to initiate the liquid-phase oxidation of cumene at 298 K was found. Individual components of the initiating system, as well as the oxidation product (hydroperoxide), do not participate in the initiated oxidation reaction. The rate of initiation was determined using the inhibitor method and by measuring the initial rate of oxidation.