Spectrokinetic Studies of the Products of Conversion of Natural Phenols in Radical Reactions

Abstract

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.