Fig. 3.
Reaction paths to high-symmetry C80 isomers (I h, D 5h) from D 3-C68 through non-classical and classical cages. D 3-C68 can grow by C2 insertion into the a non-classical structure that contains a heptagon motif, C70(hept), or b a classical structure comprised of only pentagons and hexagons, C70(7886). c For the next bottom-up cage transformation, C70 to C72, the most plausible isomers are found to be the classical cages, C72(10611), C72(10610), and heptagon-containing C72(hept1). d From those C72 isomers, reaction paths to high-symmetry C80 cages, I h-C80 and D 5h-C80, involve C2 insertion reactions and two to three SW rearrangements through classical and non-classical cage intermediates