Polfus Jonathan M
Department of Chemistry, Centre for Materials Science and Nanotechnology, University of Oslo, PO Box 1033, Blindern, N-0315, Oslo, Norway.
Commun Chem. 2023 Oct 3;6(1):213. doi: 10.1038/s42004-023-01011-3.
One-dimensional carbon chains are highly reactive allotropes that are stabilized inside the protective environment of carbon nanotubes. Here we show that carbon chains can be encapsulated in metal oxides containing open structural channels, exemplified by hollandite α-MnO. The α-MnO channels stabilize cumulene chains due to their structural commensurability, whereas the triple bonds in polyyne chains exhibit excessive steric repulsion to the oxide ions bordering the channel. Cumulene exhibits an interaction energy of only 0.065 eV per carbon atom, obtained by first-principles calculations, which is significantly more favorable than for encapsulation in a similarly sized carbon nanotube. Encapsulation of carbon chains is associated with lateral expansion of the α-MnO channel and polarization of the manganese and oxygen charge densities adjacent to the chains. Accordingly, the interaction energy is governed by a balance between van der Waals attraction and steric repulsion between the materials.
一维碳链是高活性的同素异形体，在碳纳米管的保护环境中得以稳定存在。在此我们表明，碳链能够被封装在含有开放结构通道的金属氧化物中，以钡硬锰矿α-MnO为例。α-MnO通道因其结构的可协调性而使累积烯链得以稳定，而聚炔链中的三键对通道边界的氧化物离子表现出过度的空间排斥。通过第一性原理计算得出，累积烯每个碳原子的相互作用能仅为0.065电子伏特，这比封装在尺寸相近的碳纳米管中要有利得多。碳链的封装与α-MnO通道的横向扩张以及链相邻处锰和氧电荷密度的极化有关。因此，相互作用能由材料之间范德华引力和空间排斥之间的平衡所决定。
