Steering Surface Reaction Dynamics with a Self-Assembly Strategy: Ullmann Coupling on Metal Surfaces
Steering Surface Reaction Dynamics with a Self-Assembly Strategy: Ullmann Coupling on Metal Surfaces
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通过自组装策略控制表面反应动力学：金属表面上的乌尔曼耦合
DOI：
10.1002/anie.201705018
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Shao X
中科院分区：
文献类型：
--
作者：
Zhou Xiong;Zhang Yajie;Cheng Fang;He Yang;Shen Qian;Shang Jian;Wu Kai;Wang Chenguang;Ji Wei;Shao Xiang;Chen Wei;Xu Guoqin;Wu K;Ji W;Shao X
用扫描隧道显微镜和理论计算研究了4-溴联苯在Ag(111)，Cu(111)和Cu(100)表面上的热催化Ullmann偶联反应。详细的实验证据表明，有机金属中间体在表面的初始形成，无论是作为自组装结构还是稀疏分散的物种，都是由随后的反应途径决定的。具体地说，在全覆盖下，组装的有机金属中间体经历了单势垒过程，直接转化为最终的偶联产物；而在低覆盖率下，稀疏分散的中间体在形成最终偶联产物之前，通过新发现的三叶草形状的中间体经历了双势垒过程。这些发现表明，自组装策略可以有效地控制表面反应路径和动力学。
Ullmann coupling of 4‐bromobiphenyl thermally catalyzed on Ag(111), Cu(111), and Cu(100) surfaces was scrutinized by scanning tunneling microscopy as well as theoretical calculations. Detailed experimental evidence showed that initial formation of organometallic intermediates on the surface, as self‐assembled structures or sparsely dispersed species, is determined by the subsequent reaction pathway. Specifically, the assembled organometallic intermediates at full coverage underwent a single‐barrier process to directly convert into the final coupling products, while the sparsely dispersed intermediates at low coverage went through a double‐barrier process via newly identified clover‐shaped intermediates prior to formation of the final coupling products. These findings demonstrate that a self‐assembly strategy can efficiently steer surface reaction pathways and dynamics.