Isomeric Sc2O@C78 Related by a Single-Step Stone-Wales Transformation: Key Links in an Unprecedented Fullerene Formation Pathway.
Isomeric Sc2O@C78 Related by a Single-Step Stone-Wales Transformation: Key Links in an Unprecedented Fullerene Formation Pathway.
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DOI：
10.1021/acs.inorgchem.6b01894
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发表时间：
2016-10
影响因子：
4.6
通讯作者：
Yajuan Hao;Q. Tang;Xiaohong Li;Meirong Zhang;Yingbo Wan;Lai Feng;N. Chen;Z. Slanina;L. Adamowicz-L.
中科院分区：
文献类型：
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作者：
Yajuan Hao;Q. Tang;Xiaohong Li;Meirong Zhang;Yingbo Wan;Lai Feng;N. Chen;Z. Slanina;L. Adamowicz-L.
有人提出富勒烯的形成机制包括自上而下或自下而上的途径。尽管起始点不同，但两种机制都表明，特定的富勒烯或金属富勒烯是通过包括Stone-Wales转化（SWTs）和C2损失或添加的连续逐步过程形成的。然而，由于缺失链富勒烯，很少在原子水平上定义形成途径。在此，我们提出了两个异构体簇富勒烯Sc2O@C2v(3)-C78和Sc2O@D3h(5)-C78的分离和晶体学表征，这两个异构体通过单步Stone-Wales （SW）转化密切相关。更重要的是，这些新的Sc2O@C78异构体代表了大多数溶剂萃取簇富勒烯Sc2O@C2n （n = 38-41）形成途径中明确定义的关键环节，为尚未确定的富勒烯形成机制提供了分子结构证据。此外，DFT计算显示，这些Sc2O@C78异构体的SWT具有明显的低激活势垒，这可能使既定的富勒烯形成途径合理化。进一步的表征表明，这些Sc2O@C78异构体具有不同的能带隙和电化学行为，表明SW缺陷对金属富勒烯的能量和电化学特性的影响。
It has been proposed that the fullerene formation mechanism involves either a top-down or bottom-up pathway. Despite different starting points, both mechanisms approve that particular fullerenes or metallofullerenes are formed through a consecutive stepwise process involving Stone-Wales transformations (SWTs) and C2 losses or additions. However, the formation pathway has seldomly been defined at the atomic level due to the missing-link fullerenes. Herein, we present the isolation and crystallographic characterization of two isomeric clusterfullerenes Sc2O@C2v(3)-C78 and Sc2O@D3h(5)-C78, which are closely related via a single-step Stone-Wales (SW) transformation. More importantly, these novel Sc2O@C78 isomers represent the key links in a well-defined formation pathway for the majority of solvent-extractable clusterfullerenes Sc2O@C2n (n = 38-41), providing molecular structural evidence for the less confirmed fullerene formation mechanism. Furthermore, DFT calculations reveal a SWT with a notably low activation barrier for these Sc2O@C78 isomers, which may rationalize the established fullerene formation pathway. Additional characterizations demonstrate that these Sc2O@C78 isomers feature different energy bandgaps and electrochemical behaviors, indicating the impact of SW defects on the energetic and electrochemical characteristics of metallofullerenes.