Reactions of free gold cluster cations with H2O, CH3Cl, and mixtures thereof

The reactions of the mass-selected gas-phase gold cluster cations Au-3(+) and Au-5(+) with H2O, CH3Cl, and mixtures of these reactants were studied under well-defined multi-collision conditions in an octopole ion trap. The reaction of CH3Cl with the gold cations was found to proceed fast at room temperature, leading to the adsorption of one CH3Cl molecule at each 'corner' atom of the cluster ion. This strong adsorption hindered the coadsorption of other reactants like H2O. However, a considerable reduction of the CH3Cl partial pressure led to distinct patterns of H2O/CH3Cl coadsorption products. Furthermore, the mass spectra indicated the loss of hydrogen after the reaction of CH3Cl with Au-3(+). (C) 2009 Elsevier B.V. All rights reserved.