Ab Initio heats of formation of medium-sized hydrocarbons. 13. Studies of benzo[e]pyrene, benzo[ghi]perylene, coronene, and circumcoronene

Journal Article · Thu May 14 04:00:00 EDT 1992 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/j100189a017· OSTI ID:411976

Disch, R L; Schulman, J M; Peck, R C ^[1]

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1. City Univ. of New York, Flushing, NY (United States)

The geometries and energies of the title compounds are reported at the STO-3G and 6-31G* SCF levels, except for circumcoronene, where only the STO-3G level was employed. Group equivalents and homodesmic reactions are used to obtain heats of formation from ab initio energies. At the 6-31G* SCF level, the {Delta}H{sub f}{degrees} values for the first three compounds are similar, ranging from 66.3 to 72.2 kcal/mol. Evidence of a small additional aromatic stability for coronene is found. The ab initio enthalpy changes for homodesmic reactions containing similar structural parameters are shown to be proportional to the natural logarithm of a quantity we term the Kekule ratio: the product of reactant and product Kekule numbers, each raised to a power equal to its stoichiometric coefficient. 26 refs., 1 fig., 5 tabs.

• Sponsoring Organization: USDOE
• OSTI ID: 411976
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 10 Vol. 96; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

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