ON THE FORMATION OF THE FULLERENES

The chemistry by which the closed-cage carbon clusters, C60 and C70, c an be formed in high yield out of the chaos of condensing carbon vapou r is considered. Several mechanisms for this process that have been pr oposed are critically discussed. The two most attractive are the 'pent agon road' where open sheets grow following the alternating pentagon r ule and the 'fullerene road' where, smaller fullerenes grow in small s teps in a process which finds the buckminsterfullerene (C60) local dee p energy minimum and to a lesser extent the C70 (D5h) minimum. A clear choice between the two does not seem possible with available informat ion.