Direct Observation of 4-Mercaptopyridine and Bis(4-pyridyl) Disulfide Monolayers on Au(111) in Perchloric Acid Solution Using In Situ Scanning Tunneling Microscopy
Direct Observation of 4-Mercaptopyridine and Bis(4-pyridyl) Disulfide Monolayers on Au(111) in Perchloric Acid Solution Using In Situ Scanning Tunneling Microscopy
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DOI：
10.1021/la980031w
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发表时间：
1998-05
期刊：
影响因子：
3.9
通讯作者：
T. Sawaguchi;F. Mizutani;I. Taniguchi
中科院分区：
文献类型：
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作者：
T. Sawaguchi;F. Mizutani;I. Taniguchi
用电化学扫描隧道显微镜（STM）研究了高氯酸溶液中4-巯基吡啶（PySH）和二硫代吡啶（PySSPy）在Au（111）电极上的自组装膜. PySH和PySSPy在Au（111）表面形成的单分子膜具有相同的表面特征，呈梯形结构。对于PySH和PySSPy单层，一致地观察到分子间距离为0.49和1.42 nm的有序结构，可以描述为Au（111）−SPy，这可以通过p（5 × R-30°）的矩形晶胞来解释。高分辨率的STM图像揭示了化学吸附的吡啶硫醇分子的内部结构和微取向。它们的取向与吡啶环的分子平面大多垂直于表面，但分子轴相对于表面法线相当大地倾斜。同时还发现，两个巯基吡啶分子之间通过硫部分存在分子间相互作用。
Organic monolayers of 4-mercaptopyridine (PySH) and bis(4-pyridyl) disulfide (PySSPy) self-assembled on an Au(111) electrode in perchloric acid solution were studied using electrochemical scanning tunneling microscopy (STM). Both monolayers formed from PySH and PySSPy exhibited the same surface feature on Au(111), appearing as a ladderlike structure. An ordered structure with intermolecular distances of 0.49 and 1.42 nm was consistently observed for the PySH and PySSPy monolayers describable as Au(111)−SPy, which was explained by a rectangular unit cell of p(5 × R-30°). High-resolution STM images revealed the internal structures and micro-orientation of chemisorbed pyridinethiolate molecules. They were oriented with the molecular plane of the pyridine rings mostly perpendicular to the surface, but the molecular axis considerably tilted with respect to the surface normal. It was also found that intermolecular interactions through the sulfur portions were thought to exist between two pyridinethiolate molecu...