Deb Jyotirmoy, Paul Debolina, Sarkar Utpal, Ayers Paul W
Department of Physics, Assam University, Silchar, 788011, India.
Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario, L8S 4M1, Canada.
J Mol Model. 2018 Aug 21;24(9):249. doi: 10.1007/s00894-018-3793-6.
The way the bonding and reactivity of armchair carbon nanotubes depends on the curvature of the nanotube has been investigated using density functional theory. To understand the nature of the interaction between atoms in the nanotube, the Wiberg bond index, natural bond order analysis, and topological electron density analysis have been performed. All these tools confirm that the bonds in the hydrogen-capped carbon nanotubes considered here are primarily covalent. As the diameter of the nanotube decreases and its curvature increases, the covalency (bond order) decreases, a conclusion that is supported by the increase of the bond lengths and also the decrease of the electron density and the energy density along the bond paths as the curvature increases. To shed light on the orbital contribution in bond formation and the most effective interaction between donor bonding orbital and acceptor antibonding orbital, analysis of natural bond orbitals is carried out. We have observed that the higher the nanotube diameter is, the higher the energy gap.
已使用密度泛函理论研究了扶手椅型碳纳米管的键合和反应性取决于纳米管曲率的方式。为了理解纳米管中原子间相互作用的本质，进行了维伯格键指数、自然键序分析和拓扑电子密度分析。所有这些工具都证实，这里所考虑的氢封端碳纳米管中的键主要是共价键。随着纳米管直径减小及其曲率增加，共价性（键级）降低，这一结论得到键长增加以及随着曲率增加沿键路径电子密度和能量密度降低的支持。为了阐明轨道对键形成的贡献以及供体成键轨道与受体反键轨道之间最有效的相互作用，进行了自然键轨道分析。我们观察到，纳米管直径越大，能隙越高。
