文献类型：期刊文献

英文题名：On-surface synthesis of 2D COFs on Cu(111) via the formation of thermodynamically stable organometallic networks as the template

作者：Wang, Cheng-Xin;Chen, Jian-Le;Shu, Chen-Hui[1];Shi, Ke-Ji;Liu, Pei-Nian[1]

机构：[1]East China Univ Sci & Technol, Shanghai Key Lab Funct Mat Chem, State Key Lab Chem Engn, 130 Meilong Rd, Shanghai 200237, Peoples R China; East China Univ Sci & Technol, Sch Chem & Mol Engn, 130 Meilong Rd, Shanghai 200237, Peoples R China

年份：2019

卷号：21

期号：24

起止页码：13222

外文期刊名：PHYSICAL CHEMISTRY CHEMICAL PHYSICS

收录：;EI(收录号：20201708549054);WOS:【SCI-EXPANDED(收录号:WOS:000472214000048)】；

基金：This work was supported by the National Natural Science Foundation of China (Project No. 21561162003, 21672059 and 91845110), the Program of the Shanghai Committee of Sci. & Tech. (Project No. 18520760700) and the Program for Eastern Scholar Distinguished Professor. The calculations were performed on TianHe-1 (A) at the National Supercomputer Center in Tianjin.

语种：英文

外文关键词：Copper compounds - Temperature - Bromine compounds - Chlorine compounds - Molecules - Chemical activation - Annealing

摘要：Template-directed polymerization is an effective approach used to afford regular 2D covalent organic frameworks (COFs), thus the regularity of the template is crucial for the quality of the resulting 2D COFs. For the Ullmann reactions on Cu(111), aryl iodides and bromides are activated at low temperature to form organometallic C-Cu-C structures, which lead to kinetic trapping and irregular organometallic networks. Therefore, the subsequent annealing step can only afford irregular 2D COFs. In this manuscript, the molecule 4,4 ''-dibromo-5 '-(4-chlorophenyl)-1,1 ':3 ',1 ''-terphenyl incorporated two Br terminals and one Cl terminal has been used to demonstrate different reactivities of a C-Cl bond and a C-Br bond via the hierarchical activation of the C-Br bond and the C-Cl bond on Cu(111). At room temperature, zigzag, armchair, and ring-like organometallic chains formed due to the activation of the C-Br bond to generate a C-Cu-C structure while C-Cl remained intact, illustrating that the C-Cl bond is more stable than C-Br. Further annealing at 433 K activated the C-Cl bond to produce regular organometallic networks as the thermodynamic product. Using the simpler molecule 1,3,5-tris(4-chlorophenyl)benzene as the precursor, the self-assembly of the intact molecules was observed on Cu(111) at 300 K without activation of the C-Cl bond. After annealing at 433 K, similar thermodynamically stable organometallic networks formed directly, which were used as a template to generate regular 2D COFs upon further annealing at 510 K.