文献类型：期刊文献

英文题名：Probing Electronic Superexchange Coupling at Isolated Poly-p-phenylene Molecules

作者：Wang, Weihua[3];Wang, Shiyong[3];Li, Xiuyuan[3];Collin, Jean-Paul[4];Liu, Jun[1,2];Liu, Pei Nian[1,2];Lin, Nian[3]

机构：[1]E China Univ Sci & Technol, Key Lab Adv Mat, Shanghai 200237, Peoples R China;[2]E China Univ Sci & Technol, Inst Fine Chem, Shanghai 200237, Peoples R China;[3]Hong Kong Univ Sci & Technol, Dept Phys, Hong Kong, Hong Kong, Peoples R China;[4]Univ Strasbourg, CNRS, Inst Chim, UMR 7177, F-67070 Strasbourg, France

年份：2010

卷号：132

期号：25

起止页码：8774

外文期刊名：JOURNAL OF THE AMERICAN CHEMICAL SOCIETY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000279196500042)】；

基金：This work was supported financially by Grant RPC07/08.SC11 from the Hong Kong University of Science and Technology, by the NSFC (Project No. 20902020), and by the Shanghai Pujiang Talent Program (Project No. 09PJ1403500).

语种：英文

摘要：Superexchange coupling in poly-p-phenylene molecular wires was probed using scanning tunneling microscopy/spectroscopy at cryogenic temperatures. The coupling strength was characterized by measuring the energy splitting between the molecular states constructed by symmetric and antisynnmetric dimerization of molecular fragments' orbitals. The results confirm the theoretically predicted exponential decay behavior of the superexchange coupling on a single-molecule level. A decay constant of 0.10 +/- 0.02 angstrom(-1), was obtained. Owing to the high spatial resolution of scanning tunneling microscopy, the molecules' internal states (e.g., molecular conformation) as well as external states (e.g., interaction with foreign atoms or molecules) were elucidated with atomic precision at the mean time of characterizing the superexchange coupling. This method provides a new approach to quantify how intramolecular charge transfer is influenced by molecular conformation and interaction with the surroundings.