作者:Wesley A. Chalifoux、Rik R. Tykwinski
DOI:10.1038/nchem.828
日期:2010.11
Carbyne is an allotrope of carbon composed of sp-hybridized carbon atoms. Although its formation in the laboratory is suggested, no well-defined sample is described. Interest in carbyne and its potential properties remains intense because of, at least in part, technological breakthroughs offered by other carbon allotropes, such as fullerenes, carbon nanotubes and graphene. Here, we describe the synthesis of a series of conjugated polyynes as models for carbyne. The longest of the series consists of 44 contiguous acetylenic carbons, and it maintains a framework clearly composed of alternating single and triple bonds. Spectroscopic analyses for these polyynes reveal a distinct trend towards a finite gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital for carbyne, which is estimated to be â¼485Â nm (â¼2.56Â eV). Even the longest members of this series of polyynes are not particularly sensitive to light, moisture or oxygen, and they can be handled and characterized under normal laboratory conditions. The structure of the carbon allotrope âcarbyneâ is based on a framework of sp-hybridized carbon. To model its properties, a series of conjugated polyynes â the longest of which contains 44 contiguous acetylenic carbons â have been synthesized and their spectroscopic properties investigated.
碳炔是由sp杂化碳原子组成的碳同素异形体。虽然有人提出在实验室中可以合成碳炔,但尚未有明确的样品描述。人们对碳炔及其潜在特性的兴趣仍然浓厚,至少部分原因是其他碳同素异形体(如富勒烯、碳纳米管和石墨烯)带来了技术突破。在此,我们描述了一系列共轭聚炔的合成,作为碳炔的模型。该系列中最长的由44个连续的乙炔碳组成,其结构明显由交替的单键和三键组成。对这些聚炔的光谱分析表明,碳炔的最高被占分子轨道和最低未占分子轨道之间存在一个有限的间隙,估计为≦485 nm(≦2.56 eV)。即使该系列聚炔中最长的成员对光、湿气或氧气也不特别敏感,它们可以在正常的实验室条件下进行操作和表征。碳同素异形体“碳炔”的结构基于sp杂化碳的框架。为了模拟其特性,我们合成了一系列共轭聚炔(其中最长的一组包含44个连续的乙炔碳),并研究了它们的光谱特性。