Tuning Cluster Reactivity by Charge State and Composition: Experimental and Theoretical Investigation of CO Binding Energies to AgnAum+/鈭?/sup> (n +

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• 作者：Denisia M. Popolan ; Melanie No虉ssler ; Roland Mitric虂 ; Thorsten M. Bernhardt ; Vlasta Bonac虒ic虂-Koutecky虂
• 刊名：Journal of Physical Chemistry A
• 出版年：2011
• 出版时间：February 17, 2011
• 年：2011
• 卷：115
• 期：6
• 页码：951-959
• 全文大小：951K
• 年卷期：v.115,no.6(February 17, 2011)
• ISSN：1520-5215

文摘

Temperature-dependent gas-phase reaction kinetics measurements and equilibrium thermodynamics under multicollision conditions in conjunction with ab initio DFT calculations were employed to determine the binding energies of carbon monoxide to triatomic silver鈭抔old binary cluster cations and anions. The binding energies of the first CO molecule to the trimer clusters increase with increasing gold content and with changing charge from negative to positive. Thus, the reactivity of the binary clusters can be sensitively tuned by varying charge state and composition. Also, multiple CO adsorption on the clusters was investigated. The maximum number of adsorbed CO molecules was found to strongly depend on cluster charge and composition as well. Most interestingly, the cationic carbonyl complex Au₃(CO)₄⁺ is formed at cryogenic temperature, whereas for the anion, only two CO molecules are adsorbed, leading to Au₃(CO)₂^{鈭?/sup>. All other trimer clusters adsorb three CO molecules in the case of the cations and are completely inert to CO in our experiment in the case of the anions.}