DF-DFT-SAPT Investigation of the Interaction of a Water Molecule to Coronene and Dodecabenzocoronene: Implications for the Water−Graphite Interaction

In the present study we revisit the problem of the interaction of a water molecule with a single graphite sheet. The density fitting-density functional theory-symmetry-adapted perturbation theory (DF-DFT-SAPT; J. Chem. Phys. 2005, 122, 014103) method is used to calculate the individual contributions arising from the interaction of a water molecule with various acenes, including benzene, coronene, and dodecabenzocoronene. These results are combined with calculations of the electrostatic interactions with water and a C216H36 acene to extrapolate to the limit of an infinite graphite sheet, giving a interaction energy of −2.2 kcal/mol for the water−graphite system, with the assumed geometrical structure with one hydrogen atom pointed down toward the ring system. The structure with two hydrogens pointed down is predicted to be more stable, with a net interaction energy of −2.7 kcal/mol.