Bottom-Up Formation of Antiaromatic Cyclobutadiene (c-C4H4) in Interstellar Ice Analogs,The Journal of Physical Chemistry Letters

当前位置： X-MOL 学术 › J. Phys. Chem. Lett. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Bottom-Up Formation of Antiaromatic Cyclobutadiene (c-C4H4) in Interstellar Ice Analogs
The Journal of Physical Chemistry Letters ( IF 4.8 ) Pub Date : 2024-01-25 , DOI: 10.1021/acs.jpclett.3c03524
Jia Wang _{1,

2} , Joshua H Marks _{1,

2} , André K Eckhardt ₃ , Ralf I Kaiser _{1,

2}

Affiliation

Antiaromatic cyclobutadiene (c-C₄H₄) is the simplest prototype of [n]annulenes and a key reactive intermediate with significant ring strain, serving as the model compound for antiaromatic systems in organic chemistry. Here, we report the first bottom-up formation of cyclobutadiene in low-temperature acetylene (C₂H₂) ices exposed to energetic electrons. Cyclobutadiene was isolated and detected in the gas phase upon sublimation utilizing vacuum ultraviolet photoionization reflectron time-of-flight mass spectrometry along with ultraviolet photolysis studies. These findings advance our fundamental understanding of the exotic chemistry and preparation of highly strained antiaromatic cycles through non-equilibrium chemistry in interstellar environments, thus affording a possible route for the formation of highly strained molecules such as the hitherto elusive tetrahedrane (C₄H₄). Because acetylene is a major product of the photolysis and radiolysis of methane (CH₄) ice, an abundant component of interstellar ices, our results suggest that cyclobutadiene can likely be formed in methane-rich ices of cold molecular clouds.

中文翻译：

星际冰类似物中抗芳香环丁二烯 (c-C4H4) 的自下而上形成

反芳香环丁二烯 ( c -C ₄ H ₄ ) 是[ n ]轮烯的最简单原型，也是具有显着环张力的关键反应中间体，是有机化学中反芳香体系的模型化合物。在这里，我们报告了在暴露于高能电子的低温乙炔（C ₂ H ₂ ）冰中首次自下而上形成环丁二烯。利用真空紫外光电离反射飞行时间质谱法以及紫外光解研究，在升华时分离并检测气相中的环丁二烯。这些发现推进了我们对奇异化学的基本理解，以及通过星际环境中的非平衡化学制备高应变反芳香循环，从而为形成高应变分子（例如迄今为止难以捉摸的四面体（C ₄ H ₄ ））提供了可能的途径。。由于乙炔是甲烷（CH ₄ ）冰（星际冰的丰富成分）光解和辐射解的主要产物，因此我们的结果表明环丁二烯很可能在冷分子云的富含甲烷的冰中形成。

更新日期：2024-01-25

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南