Geometries, Stabilities, and Growth Patterns of the Bimetal Mo2-doped Sin (n = 9-16) Clusters: A Density Functional Investigation
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- 作者：Ju-Guang Han ; Run-Ning Zhao ; Yuhua Duan
- 刊名：Journal of Physical Chemistry A
- 出版年：2007
- 出版时间：March 22, 2007
- 年：2007
- 卷：111
- 期：11
- 页码：2148 - 2155
- 全文大小：318K
- 年卷期：v.111,no.11(March 22, 2007)
- ISSN：1520-5215
文摘
The behaviors of the bimetal Mo-Mo doped cagelike silicon clusters Mo2Sin at the size of n = 9-16 havebeen investigated systematically with the density functional approach. The growth-pattern behaviors, relativestabilities, and charge-transfer of these clusters are presented and discussed. The optimized geometries revealthat the dominant growth patterns of the bimetal Mo-Mo doped on opened cagelike silicon clusters (n =9-13) are based on pentagon prism MoSi10 and hexagonal prism MoSi12 clusters, while the Mo2 encapsulatedSin(n = 14-16) frames are dominant growth behaviors for the large-sized clusters. The doped Mo2 dimer inthe Sin frames is dissociated under the interactions of the Mo2 and Sin frames which are examined in term ofthe calculated Mo-Mo distance. The calculated fragmentation energies manifest that the remarkable localmaximums of stable clusters are Mo2-doped Sin with n = 10 and 12; the obtained relative stabilities exhibitthat the Mo2-doped Si10 cluster is the most stable species in all different sized clusters. Natural populationanalysis shows that the charge-transfer phenomena appearing in the Mo2-doped Sin clusters are analogous tothe single transition metal Re or W doped silicon clusters. In addition, the properties of frontier orbitals ofMo2-doped Sin (n = 10 and 12) clusters show that the Mo2Si10 and Mo2Si12 isomers have enhanced chemicalstabilities because of their larger HOMO-LUMO gaps. Interestingly, the geometry of the most stable Mo2Si9 cluster has the framework which is analogous to that of Ni2Ge9 cluster confirmed by recent experimentalobservation (Goicoechea, J. M.; Sevov, S. C. J. Am Chem. Soc. 2006, 128, 4155).