Buckminsterfullerene, c60, was prepared in gram quantities by contact-arc vaporization of a graphite rod in a 100-Torr atinospherc of helium. followed by extraction of the resultant graphitic soot with toluene. The dominance of C , in this extract was verified by mass, FTIR. and NMR spectroscopy. The molecule was successfully hydrogenated to C6,H,, via a Birch reduction and dehydrogenated back to bare c 6 0 by treatment with DDQ reagent. Cyclic voltammetry of C60 in methylene chloride rcvcaled highly reversible formation of at least two stable anionic forms of c 6 0 in solution. A broad new class of thcsc fulleride and fulleronium ions is anticipated, both with the internal cavity empty and with any one of a large number of elcmcnts inside, thus providing a means of fine-tuning the chemical, optical, and redox properties.

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Generation of C 6 0 at a rate of more than 10 grams per day has been accomplished by operation of a carbon arc in an atmosphere of helium. Optimum yield of 15% was found to occur near 100-200 torr, but yields greater than 3% were found throughout the range between 50 and 760 torr.A model is proposed to explain the observed behavior based on competition between annealing of graphitic sheets to curve so that they minimize dangling bonds, and further rapid growth of these sheets in the gas phase to form giant fullerenes. In agreement with predictions of this model, laser vaporization of graphite targets was found to produce macroscopic quantities of C 6 0 only when performed in an oven above 1000 C.

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