A semiempirical (AM1) calculation on the structures and stabilities of isomers of the fullerene derivatives C60O and C70O is carried out. The ozonolysis reaction mechanism and the thermodynamics of the compounds are studied. The two isomers of C60O (56 bond and 66 bond) formed by an oxygen atom bridging across a C-C bond have an epoxide-like or an annulene-like structure. According to the ozonolysis reaction mechanism and kinetic factor analysis, the possible products of this ozonolysis reaction are C60O with oxygen bridging over the 66 bond (C2v) as an epoxide-like isomer and that with oxygen bridging over the 56 bond (Cs) as an annulene-like isomer. Further, the sixteen isomers of C70O (both epoxide-like and annulene-like structures) have been studied with respect to the same reaction mechanism. The most possible product in this ozonolysis reaction contains oxygen bridging across in the upper part (66 bond in C70O-2 or C70O-4) as an epoxide-like structure. The other possible product is C70O-8 (annulene-like structure), in which oxygen bridges across an broken equatorial CC bond in C70 (D5h). The vibrational frequency analysis and the electronic structure of the selected C60O and C70O isomers are generated for experimental characterisation. The experimental results indicate that C60O and C70O may decompose into the odd number fullerenes C59 and C69. We therefore studied the structures of C59 and C69 also.
Journal of Molecular Structure : Theochem 422(1-3), pp.153-158