Robust metal-pentagon interactions in the Th-based endohedral metallofullerenes revealed by DFT calculations
Robust metal-pentagon interactions in the Th-based endohedral metallofullerenes revealed by DFT calculations
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DOI：
10.1002/qua.25826
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发表时间：
2019-03-15
影响因子：
2.2
通讯作者：
Jin, Peng
中科院分区：
文献类型：
--
作者：
Li, Ying;Yang, Le;Jin, Peng
内包金属富勒烯（EMF）都具有明显的电荷从金属核到碳壳的转移，其中大部分电子被笼形五边形接受。本工作采用密度泛函理论方法对一系列Th@C-2n（2n = 64-88）进行了研究。有趣的是，我们发现四价钍原子主要与三个五边形环配位，金属-五边形相互作用与这些五边形之间的分布和距离无关。这种配位模式不仅与常见的有机金属配合物形成鲜明对比，其中四个五边形对于稳定Th（IV）是必不可少的，而且也不同于含Ti富勒烯，其价态高度依赖于五边形分布。钍基电磁场的特异性是合理的小金属离子的大小，低电负性，强金属笼静电吸引力和有效的金属和笼轨道之间的轨道重叠的协同效应。我们的工作突出了笼五边形在Th-笼相互作用中的作用，并指出了电磁场与常见的有机金属配合物之间的根本区别。
Endohedral metallofullerenes (EMFs) all feature obvious charge transfer from the metallic core to the carbon shell with the donated electrons largely accepted by the cage pentagons. In this work, a series of Th@C-2n (2n = 64-88) were thoroughly investigated by means of density functional theory calculations. Interestingly, we found that the tetravalent thorium atom mainly coordinates to three pentagonal rings with the metal-pentagon interactions independent on the distribution and distance among these pentagons. This coordination pattern is not only in sharp contrast to that of common organometallic complexes, where four pentagons are indispensable for stabilizing Th(IV), but also different from that of Ti-containing fullerenes, whose valence state highly depends on the pentagon distribution. The specificity of Th-based EMFs was rationalized by the synergetic effect of small metal ion size, low electronegativity, strong metal-cage electrostatic attractions and effective orbital overlap between the metal and cage orbitals. Our work highlights the role of cage pentagons in the Th-cage interactions, and points out the fundamental difference between EMFs and common organometallic complexes.