Chi Qijin, Zhang Jingdong, Ulstrup Jens
Department of Chemistry and NanoDTU, Technical University of Denmark, DK-2800 Kgs, Lyngby, Denmark.
J Phys Chem B. 2006 Jan 26;110(3):1102-6. doi: 10.1021/jp056356k.
The tert-butanethiol self-assembled monolayers (SAMs) on Au(111) surfaces were prepared from various solvents and investigated by a combination of scanning tunneling microscopy (STM) and electrochemistry in aqueous environments. High-resolution STM images reveal a (radical(7) x radical(7))R19 degrees surface lattice structure, in contrast with the conventional lattice (radical(3) x radical(3))R30 degrees structure for straight-chain alkanethiol SAMs. Interestingly, such a branched monolayer shows electrochemical rectification toward redox probes. We suggest that electrochemical rectification could be a general characteristic of short-chain branched alkanthiol SAMs, and originate in localized electronic effects.
通过多种溶剂制备了金（111）表面上的叔丁硫醇自组装单分子层（SAMs），并在水性环境中结合扫描隧道显微镜（STM）和电化学方法对其进行了研究。高分辨率STM图像揭示了一种（√7×√7）R19°的表面晶格结构，这与直链烷硫醇SAMs的传统（√3×√3）R30°晶格结构形成对比。有趣的是，这种支链单分子层对氧化还原探针表现出电化学整流作用。我们认为，电化学整流可能是短链支链烷硫醇SAMs的一个普遍特征，并且起源于局部电子效应。
