Reaction of C60 with Oxygen Initiated by Radicals from Azo(Bisisobutyronitrile)

Abstract

In an o-dichlorobenzene solution exposed to an atmosphere of air or pure oxygen, C60 reacts with radicals generated by thermal decomposition of azo(bisisobutyronitrile) and with oxygen to form mixtures of highly substituted and oxygenated monomelic, dimeric, and trimeric derivatives. LSIMS, LDMS, and SIMS (Liquid Secondary Ion, Laser Desorption, and Secondary Ion Mass Spectrometry) of these mixtures give clusters of peaks for C2n from C40 to greater than C200. Elemental analyses show large H, N, and 0 contents that increase with the amount of AIBN and the partial pressure of oxygen during the reaction. 1H and 13C NMR spectra consist of broad bands assigned to complex mixtures of substituted fullerenes containing many 2-cyano-2-propyl groups derived from AIBN. Diffuse reflectance infrared spectra show hydroxyl and carbonyl functional groups. Thermal gravimetric analysis (TGA) of the mixture prepared under oxygen retained 40% of the initial weight at 640 °C, while <19 % of the initial weight remained from the mixture prepared under argon.