Antioxidant Effect of C₆₀ and C₇₀ Fullerene in the Autoxidation of Ethyl Oleate

Abstract

The antioxidant properties of C₆₀ and C₇₀ fullerenes were studied spectrophotometrically in ethyl oleate. It was found that C₆₀ is oxidized to fullerene oxide by scavenging the peroxy radical formed in the allylic position to the double bond of ethyl oleate. The scavenging rate constant of C₆₀ has been measured and found considerably higher than that of C₇₀. Surprisingly, C₇₀ appears considerably less active than C₆₀ in scavenging the ethyl oleate autoxidation. In ethyl palmitate, a saturated fatty acid ester which does not undergo autoxidation, C₆₀, is stable and is not oxidized even at 70°C for several hours. It is also shown that cyclohexene can be used as a model compound for the study of the mechanism of solvents autoxidation and for the evaluation of the protective effect exerted by C₆₀.

Keywords:

• C₆₀
• C₇₀
• ethyl oleate
• ethyl palmitate
• autoxidation
• kinetics
• antioxidant
• peroxy radical scavenging
• cyclohexene