Stoll Paul, Lotze Christian, Ladenthin Janina N, Umbach Tobias R, Fernández-Torrente Isabel, Franke Katharina J
Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, 14195 Berlin, Germany.
J Phys Condens Matter. 2018 Nov 14;30(45):454002. doi: 10.1088/1361-648X/aae502.
A Kondo resonance has been observed on purely organic molecules in several combinations of charge transfer complexes on a metal surface. It has been regarded as a fingerprint of the transfer of one electron from the donor to the extended π orbital of the acceptor's LUMO. Here, we investigate the stoichiometric checkerboard structure of tetrathiafulvalene (TTF) and tetracyanoethylene (TCNE) on a Au(1 1 1) surface using scanning tunneling and atomic force microscopy at 4.8 K. We find a bistable state of the TCNE molecules with distinct structural and electronic properties. The two states represent different conformations of the TCNE within the structure. One of them exhibits a Kondo resonance, whereas the other one does not, despite of both TCNE types being singly charged.
在金属表面电荷转移复合物的几种组合中，已在纯有机分子上观察到近藤共振。它被视为一个电子从供体转移到受体最低未占分子轨道（LUMO）的扩展π轨道的标志。在此，我们在4.8 K下使用扫描隧道显微镜和原子力显微镜研究了金（111）表面上四硫富瓦烯（TTF）和四氰基乙烯（TCNE）的化学计量棋盘结构。我们发现TCNE分子具有双稳态，其具有不同的结构和电子性质。这两种状态代表了结构内TCNE的不同构象。其中一种表现出近藤共振，而另一种则没有，尽管两种类型的TCNE均带单电荷。
