Antioxidant properties of fullerenol-d

Fullerenol-d $\mathrm{C_{60}(OH)_{22-24}}$ was synthesized by the method of direct heterogeneous oxidation of fullerene $\mathrm{C}_{60}$, dissolved in o-xylene, by $\mathrm{NaOH}$, dissolved in water, in the presence of interphase catalyst $[t-(\mathrm{C_4H_9})_4\mathrm{N}]\mathrm{OH}$. Identification of fullerenol-d was provided by: $\mathrm{C-H-N}$ elemental analysis, High performance liquid phase chromatography, IR – and Electronic spectroscopy, Mass-spectrometry. The antioxidant properties of aqueous fullerenol-d solutions were investigated against free radicals, generated by hydrogen peroxide and molecular $\mathrm{I}_2$. Measurement of fullerenol antioxidant activity was based on the potentiometric titration of fullerenol solutions by hydrogen peroxide and molecular $\mathrm{I}_2$ solutions and vice versa with compact Pt as working electrode. As a comparison, the very popular and strong anti-oxidant – ascorbic acid was used. Pourbaix Diagrams $(pH-Eh)$ for hydrogen-oxygen and iodine forms were constructed. Fullerenol-d is a weaker antioxidant than ascorbic acid, but in contrast, fullerenols-d molecules are able to undergo multiply reversible absorption-desorption of some free radicals.