Observation of redox-state-dependent reversible local structural change of ferrocenyl-terminated molecular island by electrochemical frequency modulation AFM.
Observation of redox-state-dependent reversible local structural change of ferrocenyl-terminated molecular island by electrochemical frequency modulation AFM.
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通过电化学调频 AFM 观察二茂铁基封端分子岛的氧化还原态依赖性可逆局部结构变化。
DOI：
10.1021/la904797h
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
K. Fukui
中科院分区：
文献类型：
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作者：
Kenichi Umeda;K. Fukui
用电化学调频原子力显微镜(EC-FM-AFM)研究了在0.1MHClO(4)水溶液中，二茂铁基十一硫醇(FCC(11)H(22)SH)自组装单分子膜(SAM)在Au(111)表面的电活性。随着末端FC基团的氧化，表面FC岛的表观高度增加了约0.44 nm。这种依赖于电位的可逆变化可以通过形成离子双层来解释，其中ClO(4)(-)离子强烈地结合在FC(+)基团上。同时测量的能量耗散(对应于保持悬臂振动幅度恒定的能量)显示，FC基团的氧化状态在大小上发生了明显的变化。这些结果表明，使用EC-FM-AFM可以识别电极/电解液界面上的局域电荷，并获得界面上双电层的微观信息。
Electroactive ferrocenylundecanethiol (FcC(11)H(22)SH) islands embedded in an n-decanethiol (C(10)H(21)SH) self-assembled monolayer (SAM) matrix on Au(111) were studied under potential control in 0.1 M HClO(4) aqueous solution using newly developed electrochemical frequency-modulation atomic force microscopy (EC-FM-AFM). The apparent height of the Fc islands from the surface of the matrix SAM increased by about 0.44 nm accompanied by the oxidation of the terminal Fc groups. This potential-dependent reversible change can be explained by formation of an ionic double layer where ClO(4)(-) ions are strongly bound on the Fc(+) groups. Simultaneous measurements of energy dissipation, which corresponds to the energy to keep the cantilever's vibrational amplitude constant, revealed distinct change in the magnitude by the oxidation state of the Fc groups. These results indicate that localized charge at an electrode/electrolyte solution interface can be identified, and microscopic information on the electric double layer at the interface is available by using EC-FM-AFM.