title: Dynamic factors in the reactions between the magic cluster Al(13)⁻ and HCl/HI.
abstract: The icosahedral Al is a "magic" cluster with remarkable stability due to its high symmetry and closed valence shells. Its reactivity has provided a molecular model for understanding oxidation and dissolution processes in bulk metals. By first principles calculations, we demonstrated the importance of dynamic factors in the Al + HX reactions, with HX being either HCl or HI. There was a barrier to the dissociative adsorption of HX on the surface of an Al cluster, which involved charge transfer from Al. Furthermore, the H atom could be bonded to the cluster in multiple ways, similar to the top, bridge and hollow adsorption sites on Al(111) surface. With a large amount of energy (∼40 kcal mol(-1)) deposited during the formation of Al(13)HX(-), the H atom could easily migrate among these sites, similar to the diffusion of hydrogen on metal surfaces. These factors were therefore important considerations in the formation and dissociation of Al(13)HX(-), and more generally in reactions involving other metal clusters.
authors.affiliation: Department of Chemistry and Centre for Scientific Modeling and Computation Chinese University of Hong Kong, Shatin, Hong Kong, China.
authors.forename: Q H
authors.initials: QH
authors.lastname: Yuan
authors.forename: Jiabo
authors.initials: J
authors.lastname: Li
authors.forename: Zhi-Feng
authors.initials: ZF
authors.lastname: Liu