Interaction of gold and silver cluster cations with CH3Br: thermal and photoinduced reaction pathways
Institute of Surface Chemistry and Catalysis, University of
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Received in final form: 14 November 2010
Published online: 14 January 2011
The reactions of free, size selected Aun+ (n = 1–3, 5, 7) and Ag3+ clusters with CH3Br as well as the photodissociation of the resulting complexes at 266 nm were studied in a radio frequency ion trap under multiple collision conditions. CH3Br was found to interact more strongly with the gold clusters than with the silver clusters. All investigated metal clusters exhibited characteristic size dependent adsorbate coverages. Furthermore, the successive loss of methyl radicals was identified as a major thermal reaction channel of the adsorbed CH3Br molecules. Photodissociation experiments were performed with the product complexes of the trimer clusters and revealed the strongly preferred light-induced fragmentation of Au3Br3+ and Ag3Br3+, respectively, over any other thermal reaction products. However, whereas in the case of the gold cluster complexes the bare Au3+ was exclusively re-formed through laser irradiation, considerable photoinduced metal cluster fragmentation occurred in the case of Ag3Br3+.
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag 2011