Isolation, characterization, and chemical reactions of fullerenes
Extension of the chromatographic work that led to the first isolation of pure Go and 00 has resulted h the isolation and characterisation of c76 and three isomers of c78. Comparison with other work indicates the composition ratio of c78 to be dependent upon the method of chon production. Halogenation of Go gives derivatives that have been charactwised either by NMR, or by single aystal X-ray diffraction. The halogeno derivatives readily undergo nucleophilic substitution, which provides a route to the formation of many fullerene compounds, but precludes use of the fluoro derivatives as lubricants. In the presence of Friedel-Crafts catalysts, the bromo derivatives substitute into aromatics to give aryl derivatives of Go, especially those containing either 6, 8, 12, or 16 aryl groups per C6o molecule. Possible structures for these are compared with those for addition products which have only low eclipsing steric interactions.