Phosphorus-containing derivatives of 2,6-di(tert-butyl)phenol: The antioxidant activity and properties of the corresponding phenoxyl radicals

Abstract

The properties of phenoxyl radicals generated by the oxidation of mono-, di-, and triphosphorus derivatives of 2,6-di(tert-butyl)-4-methylphenol (ionol) were studied by ESR. These compounds exist as conformers that are interconvertible with a temperature-dependent rate. Numerical processing of the ESR spectra gave the thermodynamic and activation parameters that characterize the interconversion of the conformers. The antioxidant activities of the compounds were studied in a model oxidation of oleic acid and with biological objects. These phenols efficiently inhibited radical oxidation reactions.