Electrochemical method in determination of antioxidative activity using ferrocene derivatives as examples

Electrochemical method for the evaluation of antioxidative activity of compounds based on their reaction with the stable radical, 2,2-diphenyl-1-picrylhydrazyl, was suggested with monitoring of the reaction by cyclic voltammetry (CVA). Antioxidative properties of new ferrocene derivatives Fc(L)R (where Fc is the ferrocenyl, R is the fragment of 2,6-di-tert-butylphenol or its aromatic analog, L is the spacer) were studied. Anodic oxidation of the compounds Fc(L)R, which contain azomethine and 2,6-di-tert-butylphenol moities, proceeds in three steps, that suggests a possibility of intramolecular proton-coupled electron transfer process. Conjugates of ferrocene and 2,6-di-tert-butylphenol are efficient antioxidants.