title: Aurophilic Interactions from Wave Function, Symmetry-Adapted Perturbation Theory, and Rangehybrid Approaches.
abstract: The aurophilic interaction is examined in three model systems Au2((3)Σg(+)), (AuH)2, and (HAuPH3)2 which contain interactions of pairs of the Au centers in the oxidation state (I). Several methods are employed ranging from wave function theory-based (WFT) approaches to symmetry-adapted perturbation theory (SAPT) and range-separated hybrid (RSH) density functional theory (DFT) methods. The most promising and accurate approach consists of a combination of the DFT and WFT approaches in the RSH framework. In this combination the short-range DFT handles the slow convergence of the correlation cusp, whereas the long-range WFT is best suited for the long-range correlation. Of the three tested RSH DFT methods, the one which uses a short-range exchange functional based on the Ernzerhof-Perdew exchange hole model with a range-separation parameter of 0.4 bohr(-1) seems to be the best candidate for treatment of gold. In combination with the long-range coupled cluster singles, doubles, and noniterative triples [CCSD(T)] treatment it places the strength of aurophilic bonding in (HAuPH3)2 at 5.7 kcal/mol at R = 3.09 Å. This value is somewhat larger than our best purely WFT result based on CCSD(T), 4.95 kcal/mol (R = 3.1 Å), and considerably smaller than the Hartree-Fock+dispersion value of 7.4 kcal/mol (R = 2.9 Å). The 5.7 kcal/mol estimate fits reasonably well within the prediction of the empirical relationship proposed by Schwerdtfeger et al. (J. Am. Chem. Soc.1998, 120, 6587). A direct computation of dispersion energy, including exchange corrections, results in values of ca. -9 kcal/mol for Au2((3)Σg(+)) and (AuH)2 and -13 kcal/mol for (HAuPH3)2 at the distance of a typical aurophilic bond, R = 3.0 Å.
authors.affiliation: Crystallographie, Résonance Magnétique et Modélisations, Institut Jean Barriol, Nancy University and CNRS , F-54506 Vandoeuvre-lès-Nancy, France.
authors.forename: Ru-Fen
authors.initials: RF
authors.lastname: Liu
authors.affiliation: Department of Chemistry, Oakland University , Rochester, Michigan 48309, United States.
authors.forename: Christina A
authors.initials: CA
authors.lastname: Franzese
authors.affiliation: Department of Chemistry, Oakland University , Rochester, Michigan 48309, United States.
authors.forename: Ryan
authors.initials: R
authors.lastname: Malek
authors.affiliation: School of Chemistry, The University of Nottingham , Nottingham NG7 2RD, Great Britain.
authors.forename: Piotr S
authors.initials: PS
authors.lastname: Żuchowski
authors.affiliation: Crystallographie, Résonance Magnétique et Modélisations, Institut Jean Barriol, Nancy University and CNRS , F-54506 Vandoeuvre-lès-Nancy, France.
authors.forename: János G
authors.initials: JG
authors.lastname: Ángyán
authors.affiliation: Department of Chemistry, Oakland University , Rochester, Michigan 48309, United States.
authors.forename: Małgorzata M
authors.initials: MM
authors.lastname: Szczȩśniak
authors.affiliation: Department of Chemistry, Oakland University , Rochester, Michigan 48309, United States.|Faculty of Chemistry, University of Warsaw , Pasteura 1, 02-093 Warszawa, Poland.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Chałasiński