Reactivity of Silver Clusters Anions with Ethanethiol.

We have investigated the gas-phasereactivity of silver clusterswith ethanethiol in a fast-flow tube reactor. The primary clusterproducts observed in this reaction are AgnSH–and AgnSH2–, indicating C–S bond activation, togetherwith interesting byproducts H3S–and(H3S)2–. Agn–clusters with an odd number of valenceelectrons (n= even) were observed to be more reactivethan those with an even number of electronsa feature previouslyonly observed in the reactivity of Agn–with triplet oxygen, indicating that radicalactive sites play a role in their reactivity. Furthermore, the reactivitydramatically increases with large flow rate of ethanethiol being introducedin the flow tube. Theoretical investigations on the reactivity ofAg13–and Ag8–with ethanethiol indicate that both Ag13–and Ag8–face significant barriersto reactivity with a single ethanethiol molecule. However, Ag8–reacts readily in a cooperative reactionwith two ethanethiol molecules, consistent with the dramatic increasein reactivity with a large flow rate. Further hydrogen-transfer reactionsmay then release an ethylene molecule or an ethyl radical resultingin the observed AgnSH–species. [ABSTRACT FROM AUTHOR]