Cyclopropenylidenes: From interstellar space to an isolated derivative in the laboratory
Cyclopropenylidenes: From interstellar space to an isolated derivative in the laboratory
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DOI：
10.1126/science.1126675
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发表时间：
2006-05-05
期刊：
影响因子：
56.9
通讯作者：
Bertrand, G
中科院分区：
文献类型：
--
作者：
Lavallo, V;Canac, Y;Bertrand, G
像许多在星际介质中发现的分子物种一样，单态卡宾环丙烯叉（C3 H2）被认为太不稳定，无法在实验室中分离。然而，通过将π-供电子氨基附加到三角形骨架上，我们制备了在室温下稳定的亚环丙烯基衍生物。与先前分离的卡宾相比，该化合物不需要与缺电子碳相邻的杂原子来赋予稳定性。尽管存在的氨基，环状骨架的几何参数，揭示了X-射线晶体学，只有轻微的扰动相对于那些未取代的环亚丙基的计算结构。稳定的亚环丙烯衍生物因此可以作为模型，更好地了解星际介质中含碳分子的形成。
Like many of the molecular species that have been detected in the interstellar medium, the singlet carbene cyclopropenylidene (C3H2) has been presumed to be too unstable to isolate in the laboratory. However, by appending pi-electron-donating amino groups to the triangular skeleton, we prepared a cyclopropenylidene derivative that is stable at room temperature. In contrast to previously isolated carbenes, this compound does not require a heteroatom adjacent to the electron-deficient carbon to confer stability. Despite the presence of amino groups, the geometric parameters of the cyclic skeleton, revealed by x-ray crystallography, are only slightly perturbed relative to those of the calculated structure of unsubstituted cyclopropenylidene. Stable cyclopropenylidene derivatives might thus serve as models for a better understanding of the formation of carbon-bearing molecules in the interstellar medium.