Computational investigation of Au·H hydrogen bonds involving neutral Au N-heterocyclic carbene complexes and amphiprotic binary hydrides.

In this computational study, we investigate the ability of various neutral R-Au-NHC (NHC = N-heterocyclic carbene) complexes [R = H, CH, Cl, OH] to form hydrogen bonds with the amphiprotic binary hydrides NH, HO and HF. Optimized geometries of the adducts calculated at various levels of theory all exhibit Au⋯HX hydrogen bonds. In adducts of complexes containing NHC ligands with α(N)H units, (NH)⋯XH interactions also exist, yielding hydrogen-bonded rings with graph-set notation [Formula: see text] that correspond to pseudo chelates with κC,H coordination.

Gold(I) Hydrides as Proton Acceptors in Dihydrogen Bond Formation.

Wavefunction and DFT calculations indicate that anionic dihydride complexes of Au form strong to moderate directed Au-H⋅⋅⋅H bonds with one or two HF, H O and NH prototype proton donor molecules. The largely electrostatic interaction is influenced by relativistic effects which, however, do not increase the binding energy. Very weak Au⋅⋅⋅H associations-exhibiting a corresponding bond path-occur between neutral AuH and HF units, although ultimately F becomes the preferred donor atom in the most stable structure.

Gold setting the "gold standard" among transition metals as a hydrogen bond acceptor - a theoretical investigation.

The Au(i) atom of dimethylaurate (DMA) is shown to behave as a hydrogen-bond acceptor, providing theoretical evidence that it can act as a Lewis base. Calculations at the MP2/aug-cc-pVTZ-pp level of theory confirm that DMA forms hydrogen bonds decreasing in strength from -16.2 kcal mol to -2.

Preparing Gold(I) for Interactions with Proton Donors: The Elusive [Au]⋅⋅⋅HO Hydrogen Bond.

MP2 and DFT calculations with correlation consistent basis sets indicate that isolated linear anionic dialkylgold(I) complexes form moderately strong (ca. 10 kcal mol(-1) ) Au⋅⋅⋅H hydrogen bonds with single H2 O molecules as donors in the absence of sterically demanding substituents. Relativistic effects are critically important in the attraction.