Dimerization of pentacyclopentacorannulene C30H10 as a strategy to produce C60H20 as a precursor for C60

Abstract

The chemical synthesis of C₆₀ fullerene in the laboratory is still a challenge. In order to achieve this goal, we propose a synthetic route based on the dimerization between two pentacyclopentacorannulene (C₃₀H₁₀) fragments employing the Diels–Alder cycloaddition reaction. Density functional calculations indicate that a step wise non-concerted dimerization mechanism of C₃₀H₁₀ is favored over a one stage dimerization. The step wise dimerization implies the sequential formation of 2, 4, 6, and 10 new C–C bonds between the two fragments. This leads to the formation of the Diels–Alder cycloadduct C₆₀H₂₀. The results then suggest the synthesis of C₆₀H₂₀ as a precursor for C₆₀. The synthesis of the analogue C₆₀F₂₀ has already been reported.