Formation of oriented molecular nanowires on mica surface
Formation of oriented molecular nanowires on mica surface
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DOI：
10.1073/pnas.082644299
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发表时间：
2002-04-16
影响因子：
11.1
通讯作者：
Becher, J
中科院分区：
文献类型：
--
作者：
Akutagawa, T;Ohta, T;Becher, J
采用Langmuir-Blodgett技术在云母基质上构建了由双四噻吩取代大环和四氟四氰醌二甲烷的电荷转移配合物组成的分子“纳米线”结构。从稀氯化钾水溶液亚相转移的纳米线的典型尺寸为2.5 nm X 50 nm X 1 nm。纳米线的取向与云母表面六重对称的钾离子阵列方向一致。当使用稀水氯化铷亚相时，也观察到纳米线与衬底表面之间的这种相关性。另一方面，当亚相中含有二价阳离子时，这种相关性完全消失，表明分子纳米线通过识别云母表面的单位阵列来定向。垂直浸渍法形成的纳米线与单分子层共存。然而，当我们采用水平提升方法时，只观察到纳米线结构。根据相关配合物的晶体结构，提出了一种可能的纳米线结构。纳米线的电导率估计为10(-3)S(.)cm（-1）量级。纳米线形成了特定的（规则的）结构，如t形结，这表明它们在未来分子纳米级器件的构建中有应用。
Molecular "nanowire" structures composed of the charge transfer complex of a bis-tetrathiafulvalene substituted macrocycle and tetrafluorotetracyanoquinodimethane were constructed on mica substrates by employing the Langmuir-Blodgett technique. The nanowires transferred from a dilute aqueous potassium chloride subphase had typical dimensions of 2.5 nm X 50 nm X 1 mum. The nanowires are oriented to specific directions, corresponding to the directions of the potassium-ion array on the mica surface having sixfold symmetry. Such correlation between the nanowires and the substrate surface was also observed when a dilute aqueous rubidium chloride subphase was used. On the other hand, the correlation completely disappeared when the subphase contained divalent cations, indicating that the molecular nanowires orient by recognizing the monocation array on the mica surface. The nanowires formed by the vertical dipping method coexist with the monolayers. Only nanowire structures are, however, observed when we apply the horizontal lifting method. Based on the crystal structure of a related complex, a possible structure of the nanowires is presented. The conductivity of the nanowires was estimated to be of the order of 10(-3) S(.)cm(-1). The nanowires formed specific (regular) structures such as T-shape junctions, suggesting their use in construction of future molecular nanoscale devices.