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(HO)], formed under different conditions, exhibit spectral features that are due to the anion-molecule complex, Pt(HO), and to the reaction intermediates, HPtOH and HPtO, in which one and two O-H bonds have been broken, respectively. Additionally, the observations of PtO and H in mass spectra strongly imply that water splitting via the reaction Pt + HO → PtO + H 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 HMO intermediates. The calculated and measured VDE values are in good agreement and thus support their identification.