文献类型：期刊文献

英文题名：Suppressing the Conductance of Single-Molecule Junctions Fabricated by sp2 C-H Bond Metalation

作者：Li, Yunpeng[1];Zhang, Zekai[1];Wang, Rui[1];Tang, Ajun[1];Ma, Chaoqi[1];Lian, Cheng[1];Tian, He[1];Li, Hongxiang[1]

机构：[1]East China Univ Sci & Technol, Feringa Nobel Prize Scientist Joint Res Ctr, Frontiers Sci Ctr Materiobiol & Dynam Chem, Key Lab Adv Mat,Inst Fine Chem,Sch Chem & Mol Eng, Shanghai 200237, Peoples R China

年份：2024

卷号：16

期号：12

起止页码：15426

外文期刊名：ACS APPLIED MATERIALS & INTERFACES

收录：;EI(收录号：20241215790533);WOS:【SCI-EXPANDED(收录号:WOS:001187254700001)】；

基金：This work was supported by the National Natural Science Foundation of China (21875279, 52273176, and 22075080), Shanghai Municipal Science and Technology Major Project (grant 2018SHZDZX03), the Fundamental Research Funds for the Central Universities, the Program of Introducing Talents of Discipline to Universities (grant B16017), and Program of Shanghai Academic/Technology Research Leader (19XD1421100).

语种：英文

外文关键词：C-H bond metalation; single-moleculejunction; single-molecule insulators; Au-Cbond; electronic coupling

摘要：High-conducting single-molecule junctions have attracted a great deal of attention, but insulating single-molecule junctions, which are critical in molecular circuits, have been less investigated due to the long-standing challenges. Herein, the in situ formation of a Au-C linker via electrical-potential-mediated sp(2 )C-H bond metalation of polyfluoroarenes with the assistance of scanning tunneling microscope-based break junction technique is reported. This metalation process is bias-dependent and occurs with an electropositive electrode, and the formed junction is highly oriented. Surprisingly, these polyfluoroarenes exhibit unexpected low conductance even under short molecular lengths and are superior molecular insulators. Flicker noise analysis and DFT calculations confirm that the insulating properties of polyfluoroarenes are ascribed to their multiple fluorine substituents. Our results pave a way for constructing oriented asymmetric molecular junctions and provide an efficient strategy to suppress the single-molecule conductance, which will aid in the design of molecular insulators and advance the development of self-integrating functional molecular circuits.