开壳层金属团簇中的S-P分子轨道耦合机制研究
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- 英文论文题名：Investigation on S?P Coupling in Open-Shell Metal Clusters
- 论文作者：程世博 ; Cuneyt Berkdemir ; Joshua J.Melko ; A.W.Castleman ; Jr.
- 英文论文作者：S.B.Cheng ; C.Berkdemir ; J.J.Melko ; A.W.Castleman ; Jr. ; School of Chemistry and Chemical Engineering ; University of Shandong ; Department of Chemistry ; The Pennsylvania State University
- 年：2016
- 作者机构：山东大学化学与化工学院;Department of Chemistry,The Pennsylvania State University;
- 论文关键词：团簇稳定性 ; 理论化学 ; 光电子能谱 ; S-P分子轨道耦合
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第十八分会：电子结构理论方法的发展与应用
- 语种：中文
- 分类号：O641
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第十八分会 ; 电子结构理论方法的发展与应用
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：204k
- 原文格式：D
- 会议级别：全国
摘要
寻找具有特殊稳定性的团簇粒子(即幻数团簇)是团簇研究中的热点。在团簇结构稳定性研究方向上最著名的模型分别是Jellium闭壳层模型和无机金属芳香性模型。这两个模型一直被人们用来解释和设计具有特殊稳定性的幻数团簇。然而我们的研究结果表明并不是所有的稳定团簇都遵循这些著名模型。结合量子化学理论计算和光电子成像光谱的方法,我们发现了首个既符合Jellium闭壳层模型又具有芳香性的无机金属团簇:单重态的~1AlMg_2~-。然而,令人意想不到的是,这样一种符合两种著名模型的团簇并不是最优的能量构型。开壳层的~3AlMg_2~-比闭壳层的~1AlMg_2~-更为稳定。也就是说,之前著名的jellium闭壳层模型和芳香性模型在解释AlMg_2~-稳定性时是失效的。通过类比有机碳原子的s-p杂化理论,我们提出了一种新的团簇稳定性机制"S-P分子轨道耦合(S-P Molecular Orbital Coupling)"。该研究结果显示了Jellium模型和芳香性模型的局限性;为完善团簇稳定性模型提供了有力的理论依据;同时有希望为设计稳定的磁性团簇材料开辟新的途径。
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 ab initio calculations and photoelectron imaging spectroscopy, we present theoretical and experimental evidence on the existence of unexpectedly stable openshell clusters, which are more stable than their closed-shell and aromatic counterparts.The stabilization of these openshell Al-Mg clusters is proposed to originate from the S-P molecular orbital coupling, leading to highly stable species with increased HOMO-LUMO 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.
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 ab initio calculations and photoelectron imaging spectroscopy, we present theoretical and experimental evidence on the existence of unexpectedly stable openshell clusters, which are more stable than their closed-shell and aromatic counterparts.The stabilization of these openshell Al-Mg clusters is proposed to originate from the S-P molecular orbital coupling, leading to highly stable species with increased HOMO-LUMO 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.
引文
[1]Bergeron,D.E.;Castleman,A.W.,Jr.;Morisato,T.;Khanna,S.N.Science 2004,304:84.
[2]Li,X.;Kuznetsov,A.E.;Zhang,H.F.;Boldyrev,A.I.;Wang,L.S.Science 2001,291:859
[3]Cheng,S.B.;Berkdemir,C.;Melko,J.J.;Castleman,A.W.,Jr.J.Am.Chem.Soc.2014,136:4821.
[4]Cheng,S.B.;Berkdemir,C.;Castleman,A.W.,Jr.PNAS 2015,112:4941.(2015 PNAS Cozzarelli Prize)
[5]Cheng,S.B.;Castleman,A.W.,Jr.Sci.Rep.2015,5:12414.
[2]Li,X.;Kuznetsov,A.E.;Zhang,H.F.;Boldyrev,A.I.;Wang,L.S.Science 2001,291:859
[3]Cheng,S.B.;Berkdemir,C.;Melko,J.J.;Castleman,A.W.,Jr.J.Am.Chem.Soc.2014,136:4821.
[4]Cheng,S.B.;Berkdemir,C.;Castleman,A.W.,Jr.PNAS 2015,112:4941.(2015 PNAS Cozzarelli Prize)
[5]Cheng,S.B.;Castleman,A.W.,Jr.Sci.Rep.2015,5:12414.
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