ABSTRACT
Not surprisingly, the synthesis of the smallest fullerene is therefore much more di cult than that of C60, since the highly curved fullerene C20 is so reactive that it cannot be produced by carbon condensation or cluster annealing processes. Instead, Prinzbach et al. (2000) started from a precursor (dodecahedrane C20H20, which was rst synthesized by the Paquette group [Ternansky et al. 1982, Paquette et al. 1983]). ey replaced the hydrogen atoms with bromine atoms, and then debrominated to produce the gas-phase cage C20 fullerene. e same process is used to synthesize another C20 isomer with a bowl molecular structure. ese two isomers, together with the previously
commonly produced monocyclic ring, constitute the three major isomers of C20 that are of particular interest for this chapter.
