Belaya N.I.,Donetsk National University |
Belyi A.V.,Donetsk National University |
Pomeshchenko A.I.,Litvinenko Institute of Physical Organic Chemistry and Coal Chemistry |
Glushchenko K.V.,Donetsk National University
Russian Journal of Applied Chemistry | Year: 2015
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. © 2015 Pleiades Publishing, Ltd.