title: Face-to-face arene-arene binding energies: dominated by dispersion but predicted by electrostatic and dispersion/polarizability substituent constants.
abstract: Parallel face-to-face arene-arene complexes between benzene and substituted benzenes have been investigated at the MP2(full)/6-311G** and M05-2X/6-311G** levels of theory. A reasonably good correlation was found between the binding energies and the ∑|σ(m)| values of the substituted aromatics. It is proposed that a substituent |σ(m)| value informs on both the aromatic substituent dispersion/polarizability and the effect the substituent has on the aromatic electrostatics. Supporting this hypothesis, a combination of electrostatic (∑σ(m)) and dispersion/polarizability (∑M(r)) substituent constant terms gives an excellent, and statistically significant, correlation with the benzene-substituted benzene binding energy. Symmetry adapted perturbation theory energy decomposition calculations show the dominant attractive force is dispersion; however, the sum of all nonelectrostatic forces is essentially a constant, while the electrostatic component varies significantly. This explains the importance of including an electrostatic term when predicting benzene-substituted benzene binding energies.
authors.affiliation: Department of Chemistry, Saint Louis University, 3501 Laclede Avenue, Saint Louis, Missouri 63103, United States.
authors.forename: Michelle
authors.initials: M
authors.lastname: Watt
authors.forename: Laura K E
authors.initials: LK
authors.lastname: Hardebeck
authors.forename: Charles C
authors.initials: CC
authors.lastname: Kirkpatrick
authors.forename: Michael
authors.initials: M
authors.lastname: Lewis
mesh_terms: D001554:Benzene / Q000737:chemistry*; D003500:Cyclization; D055672:Static Electricity
chemical_list: D001554:Benzene