Fig. 9: Potential energy diagram leading to the C40 nanobowl.

Calculated potential energy diagrams for the conversion of pentabenzocorannulene (C40H20) to C40H18 (a) and C40H12 to the C40 nanobowl (C40H10) (b) via a hydrogen abstraction–cyclodehydrogenation mechanism. Relative energies of various species calculated at the DLPNO-CCSD(T)/cc-pVDZ level of theory are given in kJ mol−1 with respect to the initial reactants. A full version of the diagram for all five hydrogen atom abstraction–cyclodehydrogenation steps along with the Cartesian coordinates is available in Supplementary Fig. 10 and Supplementary Data 3 and 4. Carbon atoms are gray and hydrogen atoms are white.