Communication: Water activation and splitting by single metal-atom anions.

We report experimental and computational results pertaining to the activation and splitting of single water molecules by single atomic platinum anions. The anion photoelectron spectra of [Pt(H2O)]-, formed under different conditions, exhibit spectral features that are due to the anion-molecule complex, Pt-(H2O), and to the reaction intermediates, HPtOH- and H2PtO-, in which one and two O-H bonds have been broken, respectively. Additionally, the observations of PtO- and H2 + in mass spectra strongly imply that water splitting via the reaction Pt- + H2O → PtO- + H2 has occurred. Extending these studies to nickel and palladium shows that they too are able to activate single water molecules, as evidenced by the formation of the reaction intermediates, HNiOH- and HPdOH-. Computations at the coupled cluster singles and doubles with perturbatively connected triples level of theory provide structures and vertical detachment energies (VDEs) for both HMOH- and H2MO- intermediates. The calculated and measured VDE values are in good agreement and thus support their identification.