S-P Coupling Induced Unusual Open-Shell Metal Clusters
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- 作者：Shi-Bo Cheng ; Cuneyt Berkdemir ; Joshua J. Melko ; A. W. Castleman ; Jr.
- 刊名：Journal of the American Chemical Society
- 出版年：2014
- 出版时间：April 2, 2014
- 年：2014
- 卷：136
- 期：13
- 页码：4821-4824
- 全文大小：257K
- 年卷期：v.136,no.13(April 2, 2014)
- ISSN：1520-5126
文摘
Metal clusters featuring closed supershells or aromatic character usually exhibit remarkably enhanced stability in their cluster series. However, not all stable clusters are subject to these fundamental constraints. Here, by employing photoelectron imaging spectroscopy and ab initio calculations, we present experimental and theoretical evidence on the existence of unexpectedly stable open-shell clusters, which are more stable than their closed-shell and aromatic counterparts. The stabilization of these open-shell Al-Mg clusters is proposed to originate from the S-P molecular orbital coupling, leading to highly stable species with increased HOMO鈥揕UMO gaps, akin to s-p hybridization in an organic carbon atom that is beneficial to form stable species. Introduction of the coupling effect highlighted here not only shows the limitations of the conventional closed-shell model and aromaticity but also provides the possibility to design valuable building blocks.