Homo-coupling of terminal alkynes on a noble metal surface
Homo-coupling of terminal alkynes on a noble metal surface
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DOI：
10.1038/ncomms2291
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发表时间：
2012-12-01
影响因子：
16.6
通讯作者：
Barth, Johannes V.
中科院分区：
文献类型：
--
作者：
Zhang, Yi-Qi;Kepcija, Nenad;Barth, Johannes V.
乙炔的共价连接为制造新型碳基支架和不同于石墨烯的二维材料提供了重要途径。到目前为止，很少有人试图在定义明确的界面或单层模板实施这一策略。在这里，我们展示了通过真实的空间直接可视化和操纵结合X射线光电子能谱和密度泛函理论计算的银表面介导的末端炔C-sp - H键的激活和伴随的同质耦合的过程中正式想起经典的B-H型反应。炔均偶联反应是在真空条件下，在Ag（111）贵金属表面上进行的，反应过程中没有过渡金属催化剂的存在，副产物为挥发性的H-2。与所采用的多主题乙炔物种，我们证明了一个分层的反应途径，提供离散的化合物或聚合物网络具有共轭骨架。这为表面共价化学和二维富碳或全碳聚合物的实现提供了一种新的方法。
The covalent linking of acetylenes presents an important route for the fabrication of novel carbon-based scaffolds and two-dimensional materials distinct from graphene. To date few attempts have been reported to implement this strategy at well-defined interfaces or monolayer templates. Here we demonstrate through real space direct visualization and manipulation in combination with X-ray photoelectron spectroscopy and density functional theory calculations the Ag surface-mediated terminal alkyne C-sp - H bond activation and concomitant homo-coupling in a process formally reminiscent of the classical Glaser-Hay type reaction. The alkyne homo-coupling takes place on the Ag(111) noble metal surface in ultrahigh vacuum under soft conditions in the absence of conventionally used transition metal catalysts and with volatile H-2 as the only by-product. With the employed multitopic ethynyl species, we demonstrate a hierarchic reaction pathway that affords discrete compounds or polymeric networks featuring a conjugated backbone. This presents a new approach towards on-surface covalent chemistry and the realization of two-dimensional carbon-rich or all-carbon polymers.