Gas-Phase Heat of Formation Values for Buckminsterfullerene (C60), C70 Fullerene (C70), Corannulene, Coronene, Sumanene,
and Other Polycyclic Aromatic Hydrocarbons Calculated Using Density
Functional Theory (M06 2X) Coupled with a Versatile Inexpensive Group-Equivalent
Approach
posted on 2018-08-02, 17:40authored byJohn A. Bumpus
A straightforward procedure using
density functional theory (M06
2X) coupled with a group-equivalent approach is described that was
used to calculate gas-phase heat of formation (ΔfH°g,298) values for buckminsterfullerene
(C60), C70 fullerene (C70), corannulene, coronene,
and sumanene. This procedure was also used to calculate exceptionally
accurate ΔfH°g,298 values for a variety of single-ring aromatic and 2–7 ring
polycyclic aromatic hydrocarbons (PAHs) as well as a large selection
of other hydrocarbons and phenols. The approach described herein is
internally consistent, and results for C60, C70, corannulene, coronene, and sumanene are in very close agreement
with results reported by others who used higher-level computational
theory. Statistical analysis of a test set containing benzene and
18 two to seven ring PAHs demonstrated that by using this approach
a mean absolute deviation (MAD) and a root-mean-square deviation (RMSD)
of 0.8 and 1.3 kJ/mol, respectively, were achieved for reference/experimental
ΔfH°g,298 values
versus calculated/predicted ΔfH°g,298 values. For statistical analysis of a larger test set
containing 235 aromatic and aliphatic hydrocarbons and phenols, a
MAD and a RMSD of 1.2 and 1.9 kJ/mol, respectively, were achieved
for reference/experimental ΔfH°g,298 values versus calculated/predicted ΔfH°g,298 values.