Activation of Multiple CH Bonds Promoted by Gold in AuNbO3+Clusters

Selective Activation of the C-H Bond in Methane by Single Platinum Atomic Anions

Mass spectrometric analysis of the anionic products of interaction between platinum atomic anions, Pt^- , and methane, CH₄ and CD₄ , in a collision cell shows the preferred generation of [PtCH₄ ]^- and [PtCD₄ ]^- complexes and a low tendency toward dehydrogenation. [PtCH₄ ]^- is shown to be H-Pt-CH₃ ^- by a synergy between anion photoelectron spectroscopy and quantum chemical calculations, implying the rupture of a single C-H bond. The calculated reaction pathway accounts for the observed selective activation of methane by Pt^- . This study presents the first example of methane activation by a single atomic anion.

Generation of Hydroxyl Radicals in the Reaction of Dihydrogen with AuNbO4+ Cluster Cations

A molecular-level insight into the nature of reactive oxygen species involved in dihydrogen (H₂ ) dissociation is of great importance to understand gold catalysis. In this study, laser ablation generated and mass-selected AuNbO₄⁺ oxide cluster cations could dissociate H₂ in an ion-trap reactor. The reaction has been characterized by time-of-flight mass spectrometric experiments and density functional calculations. The lowest energy isomer of AuNbO₄⁺ contains two lattice oxygen (O^2- ) and one superoxide (O₂^.- ) species. The gold atom anchors the H₂ molecule in the first step and then delivers one hydrogen atom to the O^2- ion in H₂ dissociation. At the same time, O₂^.- is reduced into a peroxide unit that can accept the second hydrogen atom of H₂ with the generation of a hydroxyl radical as the main product. In this study, the important roles of the O₂^.- unit in the dissociation of H₂ have been identified.

Highly regioselective hydride transfer, oxidative dehydrogenation, and hydrogen-atom abstraction in the thermal gas-phase chemistry of [Zn(OH)]+/C3H8

The metal center of [Zn(OH)]⁺ serves as active site in the regiospecific hydride transfer to generate [i-C₃H₇]⁺ as major product in the reaction with C₃H₈. In the [Zn(OH)]⁺–C₃H₈ system, a high regioselectivity features the remarkable chemoselectivity.