英国牛津大学Anderson, Harry L.团队报道了用于螺纹碳链合成的掩蔽炔烃。相关研究成果于2023年11月16日发表在《自然—化学》。

炔烃是具有交替单键和三键的sp1碳原子链。随着它们变长，它们向碳的¹D同素异形体碳炔转化，并且变得越来越不稳定。人们预计，长的聚炔可以通过超分子封装来稳定，通过将它们穿过大环形成聚轮烷。但到目前为止，具有许多螺纹大环的聚炔-聚轮烷在合成上是不可获得的。

该文中，研究人员证明了掩蔽炔烃，其中C≡C三键暂时与钴配位，可以用于合成聚轮烷，直到形成具有34个连续三键和四个螺纹大环的C68[5]轮烷。这是聚炔的电子性质收敛于碳炔的电子性能的长度范围。环碳构成了一个相关的分子碳同素异形体家族，钴掩蔽的炔烃也提供了一条制备[3]链烯和[5]链烯的途径，它们分别围绕环[40]碳和环[80]碳的钴络合物构建。

附：英文原文

Title: Masked alkynes for synthesis of threaded carbon chains

Author: Patrick, Connor W., Gao, Yueze, Gupta, Prakhar, Thompson, Amber L., Parker, Anthony W., Anderson, Harry L.

Issue&Volume: 2023-11-16

Abstract: Polyynes are chains of sp1 carbon atoms with alternating single and triple bonds. As they become longer, they evolve towards carbyne, the 1D allotrope of carbon, and they become increasingly unstable. It has been anticipated that long polyynes could be stabilized by supramolecular encapsulation, by threading them through macrocycles to form polyrotaxanes—but, until now, polyyne polyrotaxanes with many threaded macrocycles have been synthetically inaccessible. Here we show that masked alkynes, in which the C≡C triple bond is temporarily coordinated to cobalt, can be used to synthesize polyrotaxanes, up to the C68 [5]rotaxane with 34 contiguous triple bonds and four threaded macrocycles. This is the length regime at which the electronic properties of polyynes converge to those of carbyne. Cyclocarbons constitute a related family of molecular carbon allotropes, and cobalt-masked alkynes also provide a route to [3]catenanes and [5]catenanes built around cobalt complexes of cyclo[40]carbon and cyclo[80]carbon, respectively.

DOI: 10.1038/s41557-023-01374-z

Source: https://www.nature.com/articles/s41557-023-01374-z