Evaluation of the heats of formation of corannulene and C60 by means of inexpensive theoretical procedures.

Inexpensive ab initio procedures that employ homologous sequences of isodesmic reactions for the calculation of enthalpies of formation of moderate-sized organic molecules were tested with benzene, naphthalene, phenanthrene, and triphenylene. Two size-consistent adjustable parameters were found to bring the calculated values within the uncertainty of the experimental values. These procedures were then applied to C20H10 (corannulene) and C60 (buckminsterfullerene). The results, specifically, Δ(f)H(298)(0)(C20H10) = 484 ± 4 kJ mol(-1) and Δ(f)H(298)(0)(C60) = 2531 ± 15 kJ mol(-1), are in excellent agreement with both the recent definitive W1h calculations of Karton et al. for corannulene [Δ(f)H(298)(0)(C20H10) = 485.2 ± 7.9 kJ mol(-1)] and their estimated value for buckminsterfullerene [Δ(f)H(298)(0)(C60) = 2521.6 ± 13.6 kJ mol(-1)] ( J. Phys. Chem. A 2013, 117, 1834-1842). We support their conclusion that the experimental values should be reexamined.