Li Guangxia, Meng Lingpeng, Zhang Huaiyu, Li Xiaoyan, Zeng Yanli
Institute of Computational Quantum Chemistry, College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050024, P. R. China.
Phys Chem Chem Phys. 2020 Aug 28;22(32):18071-18077. doi: 10.1039/d0cp02594a. Epub 2020 Aug 6.
The small molecule clusters have received more and more attention due to their widespread applications in chemical insulators, explosives, semiconductors and the high energy density materials industry. The electron deficiency of group IIIA elements endows their clusters with interesting properties. In this work, the electronic structures of M (M = B, Al, Ga) have been investigated by means of a complete active space self-consistent field (CASSCF) method. The nature of the chemical bond has been analyzed using the quantum theory of atoms in molecules (QTAIM) and electron localization function (ELF) analyses. The following conclusions can be drawn: in M (M = B, Al, Ga) clusters, two π electrons are shared by three atoms forming a 3c-2e delocalization π bond. Going from B to Al to Ga, more and more electrons move from the bond pair to the outside of the M atom, which leads to a gradual enhancement of the delocalization of σ electrons. Aromaticity and the adaptive natural density partitioning (AdNDP) analyses reveal the existence of the 3c-2e π bond and delocalization of σ electrons in the studied systems.
小分子团簇因其在化学绝缘体、炸药、半导体和高能量密度材料工业中的广泛应用而受到越来越多的关注。IIIA族元素的缺电子特性赋予了它们的团簇有趣的性质。在这项工作中，采用完全活性空间自洽场（CASSCF）方法研究了M（M = B、Al、Ga）的电子结构。使用分子中的原子量子理论（QTAIM）和电子定域函数（ELF）分析对化学键的性质进行了分析。可以得出以下结论：在M（M = B、Al、Ga）团簇中，两个π电子由三个原子共享，形成一个3c-2e离域π键。从B到Al再到Ga，越来越多的电子从键对转移到M原子外部，这导致σ电子的离域逐渐增强。芳香性和自适应自然密度划分（AdNDP）分析揭示了所研究体系中3c-2e π键的存在和σ电子的离域。
