The versatility of carbon is revealed in its all-carbon forms (allotropes), which feature unique properties (consider the differences between diamond, graphite, graphene and fullerenes). Beyond natural sources, there are many opportunities to expand the realm of carbon chemistry through the study of new carbon forms. In this work, the synthesis of oligo-/polyynes is used to model the elusive carbyne. The chemical stabilization of oligoynes by sterically encumbered endgroups, particularly the 3,5-bis(3,5-di-tert-butylphenyl)pyridyl group, is key to assemble an extended series of stable oligoynes. The final member of this series is the longest monodisperse polyyne isolated and characterized so far, featuring 24 contiguous alkyne units (48 carbons). Spectroscopic and X-ray crystallographic analysis show that endgroups influence the properties of oligoyne derivatives, but this effect diminishes as length increases toward the polyyne/carbyne limit. For instance, with ultraviolet–visible spectroscopy, molecular symmetry clearly documents the evolution of characteristics from oligoynes to polyynes (in which endgroup effects are absent). The combined experimental data are used to refine predictions for the D_∞h structure of carbyne.

碳的多功能性体现在其全碳形式（同素异形体）中，它具有独特的性质（考虑金刚石、石墨、石墨烯和富勒烯之间的差异）。除了自然资源之外，还有很多机会可以通过研究新的碳形式来扩展碳化学领域。在这项工作中，低聚/聚炔的合成用于模拟难以捉摸的卡炔。由空间位阻末端基，特别是3,5-双（3,5-二- oligoynes的化学稳定化叔-丁基苯基）吡啶基是组装一系列稳定低聚炔的关键。该系列的最后一个成员是迄今为止分离和表征的最长的单分散聚炔，具有 24 个连续的炔烃单元（48 个碳）。光谱和 X 射线晶体学分析表明，端基会影响低聚炔衍生物的性质，但这种影响会随着长度向聚炔/碳炔极限增加而减弱。例如，使用紫外-可见光谱，分子对称性清楚地记录了从低聚炔到聚炔（其中不存在端基效应）的特征演变。组合的实验数据用于改进对_碳炔的D _∞h结构的预测。