Yu Xin, Li Xin, Lin Haiping, Liu Mengxi, Cai Liangliang, Qiu Xia, Yang Dandan, Fan Xing, Qiu Xiaohui, Xu Wei
Interdisciplinary Materials Research Center, College of Materials Science and Engineering, Tongji University, Shanghai 201804, People's Republic of China.
CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China.
J Am Chem Soc. 2020 May 6;142(18):8085-8089. doi: 10.1021/jacs.0c01925. Epub 2020 Apr 27.
The structural transformation from symmetric cumulene to broken-symmetry polyyne within a one-dimensional (1-D) atomic carbon chain is a signature of Peierls distortion. Direct observation of such a structural transformation with single-bond resolution is, however, still challenging. Herein, we design a molecule with a cumulene moiety (BrC═C═C═CBr) and employ STM tip manipulation to achieve the molecular skeleton rearrangement from a cumulene to a diyne moiety (Br-C≡C-C≡C-Br). Furthermore, by an on-surface reaction strategy, thermally induced entire debromination (:C═C═C═C:) leads to the formation of a 1-D organometallic polyyne (-C≡C-C≡C-Au-) with a semiconducting characteristic, which implies that a Peierls-like transition may occur in a rationally designed molecular system with limited length.
在一维（1-D）原子碳链中从对称累积烯到破缺对称聚炔的结构转变是派尔斯畸变的一个标志。然而，以单键分辨率直接观察这种结构转变仍然具有挑战性。在此，我们设计了一种带有累积烯部分（BrC═C═C═CBr）的分子，并采用扫描隧道显微镜（STM）针尖操纵来实现分子骨架从累积烯到二炔部分（Br-C≡C-C≡C-Br）的重排。此外，通过表面反应策略，热诱导的完全脱溴（:C═C═C═C:）导致形成具有半导体特性的一维有机金属聚炔（-C≡C-C≡C-Au-），这意味着在具有有限长度的合理设计的分子体系中可能发生类似派尔斯的转变。
