CAS Key Laboratory of Molecular Nanostructure and Nanotechnology and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing, 100190, China.
College of Chemistry, Chemical Engineering and Materials Science Key Laboratory of Molecular and Nano Probes Ministry of Education, Shandong Normal University, Jinan, Shandong, 250014, China.
Chem Asian J. 2020 Sep 1;15(17):2627-2630. doi: 10.1002/asia.202000593. Epub 2020 Aug 3.
The on-surface coupling reactions of terminal alkynes catalyzed by exogenous cupric ions on chemically inert highly oriented pyrolytic graphite (HOPG) surface have been investigated by scanning tunnelling microscopy. In the presence of exogenous cupric ions, diyne-linked nanostructures generated via homocoupling of terminal alkynes are the exclusive products, whereas no coupling reaction occurs for the terminal alkynes on the surface in the absence of the cupric ions, suggesting that exogenous cupric ions are efficient to catalyze the highly chemoselective on-surface reaction of terminal alkynes. The HOPG surface displays a template effect to the growth and alignment of the products on the surface. As a result, 2D arrays of diyne-linked zigzag polymers and 2D diyne-linked porous polymers are fabricated from ditopic monomer 3,6-diethynylcarbazole and tritopic monomer 1,3,5-tris-(4-ethynylphenyl) benzene, respectively. This synthetic strategy combining the high selectivity of cupric ion catalyst as well as the template effect of on-surface synthesis approach could be a general strategy to fabricate diyne-linked nanostructures and nanomaterials on solid surfaces.
在化学惰性的高取向热解石墨（HOPG）表面上，通过扫描隧道显微镜研究了外源铜离子催化末端炔烃的表面偶联反应。在外源铜离子存在的情况下，通过末端炔烃的同偶联生成的二炔键连接的纳米结构是唯一的产物，而在没有铜离子的情况下，表面上的末端炔烃不发生偶联反应，这表明外源铜离子有效地催化了末端炔烃的高化学选择性表面反应。HOPG 表面对产物在表面上的生长和排列具有模板效应。因此，分别由双功能单体 3,6-二乙炔基咔唑和三功能单体 1,3,5-三（4-乙炔基苯基）苯合成了二维二炔键连接的锯齿聚合物和二维二炔键连接的多孔聚合物阵列。这种将铜离子催化剂的高选择性与表面合成方法的模板效应相结合的合成策略可能是在固体表面上制备二炔键纳米结构和纳米材料的通用策略。
