Structures and Electronic Properties of Al7X0,- and Al13X1,2,12- Clusters with X=F, Cl, and Br
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- 作者：Jiao Sun ; Wen-Cai Lu ; Li-Zhen Zhao ; Wei Zhang ; Ze-Sheng Li ; Chia-Chung Sun
- 刊名：Journal of Physical Chemistry A
- 出版年：2007
- 出版时间：May 24, 2007
- 年：2007
- 卷：111
- 期：20
- 页码：4378 - 4383
- 全文大小：338K
- 年卷期：v.111,no.20(May 24, 2007)
- ISSN：1520-5215
文摘
The structures, binding energies, and electronic properties for Al7X, Al7X-, Al13X-, Al13X2-, and Al13X12-(X = F, Cl, Br) were studied at the B3LYP/6-311+G(2d,p) level. Among the systems studied, Al7 and Al13clusters in Al7X and Al13X- reveal alkali-like and halogen-like superatom characters, respectively. Al7 canbind with one halogen atom to form a salt-like compound as Al7+
-X-. Al13- can combine with one halogenatom to form a diatomic halogen anion Al13X-. However, when adding more halogens, the superatom structurewould be destroyed, resulting in low-symmetry compounds with the center Al atom moving toward the clustersurface. The structures of Al13X1,2,12- (X = F, Cl, Br) are similar to those of X = I; however, their bindingenergies and electron structures are much different. In addition, the analyses of the calculated NBO chargesshow that Cl and Br have similar properties, but much different from F, when interacting with the Al clusters.The Al-Cl and Al-Br bonds have more covalent character in Al7X and Al13X2,12-, in contrast to thecorresponding Al-F bond, which has prominent ionic character.
-X-. Al13- can combine with one halogenatom to form a diatomic halogen anion Al13X-. However, when adding more halogens, the superatom structurewould be destroyed, resulting in low-symmetry compounds with the center Al atom moving toward the clustersurface. The structures of Al13X1,2,12- (X = F, Cl, Br) are similar to those of X = I; however, their bindingenergies and electron structures are much different. In addition, the analyses of the calculated NBO chargesshow that Cl and Br have similar properties, but much different from F, when interacting with the Al clusters.The Al-Cl and Al-Br bonds have more covalent character in Al7X and Al13X2,12-, in contrast to thecorresponding Al-F bond, which has prominent ionic character.