Al62- - Fusion of Two Aromatic Al3- Units. A Combined Photoelectron Spectroscopy and ab Initio Study of M+[Al62<
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- 作者：Aleksey E. Kuznetsov ; Alexander I. Boldyrev ; Hua-Jin Zhai ; Xi Li ; and Lai-Sheng Wang
- 刊名：Journal of the American Chemical Society
- 出版年：2002
- 出版时间：October 2, 2002
- 年：2002
- 卷：124
- 期：39
- 页码：11791 - 11801
- 全文大小：716K
- 年卷期：v.124,no.39(October 2, 2002)
- ISSN：1520-5126
文摘
Photoelectron spectroscopy is combined with ab initio calculations to elucidate the structureand chemical bonding of a series of MAl6- (M = Li, Na, K, Cu, and Au) bimetallic clusters. Well-resolvedphotoelectron spectra were obtained for MAl6- (M = Li, Na, Cu, and Au) at several photon energies. Theab initio calculations showed that all of the MAl6- clusters can be viewed as an M+ cation interacting withan Al62- dianion. Al62- was found to possess an Oh ground-state structure, and all of the MAl6- clusterspossess a C3v ground-state structure derived from the Oh Al62-. Careful comparison between thephotoelectron spectral features and the ab initio one-electron detachment energies allows us to establishfirmly the C3v ground-state structures for the MAl6- clusters. A detailed molecular orbital (MO) analysis isconducted for Al62- and compared with Al3-. It was shown that Al62- can be considered as the fusion oftwo Al3- units. We further found that the preferred occupation of those MOs derived from the sums of theempty 2e' MOs of Al3-, rather than those derived from the differences between the occupied 2a1' and 2a2' 'MOs of Al3-, provides the key bonding interactions for the fusion of the two Al3- into Al62-. Because thereare only four bonding MOs (one 
pi.gif" BORDER=0 > and three 
MOs), an analysis of resonance structures was performedfor the Oh Al62-. It is shown that every face of the Al62- octahedron still possesses both pi.gif" BORDER=0 >- and -aromaticity,analogous to Al3-, and that in fact Al62- can be viewed to possess three-dimensional pi.gif" BORDER=0 >- and -aromaticitywith a large resonance stabilization.
pi.gif" BORDER=0 > and three MOs), an analysis of resonance structures was performedfor the Oh Al62-. It is shown that every face of the Al62- octahedron still possesses both pi.gif" BORDER=0 >- and -aromaticity,analogous to Al3-, and that in fact Al62- can be viewed to possess three-dimensional pi.gif" BORDER=0 >- and -aromaticitywith a large resonance stabilization.