Nature of Bonding in Bowl-Like B36 Cluster Revisited: Concentric (6+18) Double Aromaticity and Reason for the Preference of a Hexagonal Hole in a Central Location
Nature of Bonding in Bowl-Like B36 Cluster Revisited: Concentric (6+18) Double Aromaticity and Reason for the Preference of a Hexagonal Hole in a Central Location
复制标题
重新审视碗状 B36 团簇中的键合性质：同心（6 pi 加 18 pi）双芳香性以及偏爱中心位置六角形孔的原因
DOI：
10.1002/asia.201800174
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发表时间：
2018-05-04
影响因子：
4.1
通讯作者：
Zhai, Hua-Jin
中科院分区：
文献类型：
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作者：
Li, Rui;You, Xue-Rui;Zhai, Hua-Jin
具有中心六边形孔的碗形C-6v B-36簇被认为是低维硼基纳米系统的理想分子模型。由于硼的电子缺乏，B-36星团中的化学键是有趣的，复杂的，尽管在文献中有几篇论文，但仍然难以捉摸。本文通过典型分子轨道（cmo）和自适应自然密度分配（AdNDP），以及自然键轨道（NBO）分析和轨道组成计算，给出了成键分析。协调一致的计算数据建立了B-36团簇的同心双芳构性思想，其内部有6个电子计数，外部有18个电子计数，都符合（4n+2）哈克规则。更新后的键合图与现有的系统知识不同。提出了一种精细的冕烯键合模型，其中B-36簇是一种无机类似物。进一步表明，无论六边形孔洞的迁移如何，B-36簇中的同心双芳构性都保持不变，并且在空间上是固定的；后一个过程有力地改变了体制。六角形孔洞是sigma/ cmo的不稳定因素。中心的六边形孔影响的cmo大大减少，因此使碗形的C-6v B-36簇成为全球最小的。
The bowl-shaped C-6v B-36 cluster with a central hexagon hole is considered an ideal molecular model for low-dimensional boron-based nanosystems. Owing to the electron deficiency of boron, chemical bonding in the B-36 cluster is intriguing, complicated, and has remained elusive despite a couple of papers in the literature. Herein, a bonding analysis is given through canonical molecular orbitals (CMOs) and adaptive natural density partitioning (AdNDP), further aided by natural bond orbital (NBO) analysis and orbital composition calculations. The concerted computational data establish the idea of concentric double aromaticity for the B-36 cluster, with inner 6 and outer 18 electron counting, which both conform to the (4n+2) Huckel rule. The updated bonding picture differs from existing knowledge of the system. A refined bonding model is also proposed for coronene, of which the B-36 cluster is an inorganic analogue. It is further shown that concentric double aromaticity in the B-36 cluster is retained and spatially fixed, irrespective of the migration of the hexagonal hole; the latter process changes the system energetically. The hexagonal hole is a destabilizing factor for sigma/ CMOs. The central hexagon hole affects substantially fewer CMOs, thus making the bowl-shaped C-6v B-36 cluster the global minimum.