Electrochemically grafted single molecule junctions exploiting a chemical protection strategy
Electrochemically grafted single molecule junctions exploiting a chemical protection strategy
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DOI：
10.1016/j.electacta.2016.10.095
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发表时间：
2016-12-01
影响因子：
6.6
通讯作者：
Nichols, Richard J.
中科院分区：
文献类型：
--
作者：
Liang, Jinghong;Smith, Robert E. G.;Nichols, Richard J.
制备了适于单分子电导研究的重氮接枝低聚亚苯基乙炔（OPE）单分子膜。表面结合的OPE由氨基二苯乙炔，4-（2-（4-（2-（三异丙基甲硅烷基）乙炔基）苯基）乙炔基）苄胺制备，其原位转化为重氮衍生物，随后使用常规阴极电化学接枝连接到金基底。通过大体积的三异丙基甲硅烷基（TIPS）保护的乙炔基的存在避免多层形成。在通过用氟化物处理去除TIPS基团后，现在带有暴露的末端乙炔部分的膜通过使用Sonogashira偶联化学与1-碘-4-乙酰基硫代苯反应进一步官能化，以产生带有强烈亲金性顶部接触基团的位点。使用拉曼光谱（分别采用金纳米颗粒和SiO2涂覆的金纳米颗粒的间隙模式和SHINERS）证实这些表面反应的成功。结果表明，这样的硫醇盐改性，重氮接枝的单层膜是适合STM为基础的分子结电导测量。(C)2016作者爱思唯尔有限公司出版
Diazonium grafted oligo(phenylene ethynylene) (OPE) monolayers suitable for single molecule conductance studies have been prepared. The surface-bound OPE is prepared from the amino tolan, 4-(2-(4-(2-(triisopropylsilyl)ethynyl)phenyl)ethynyl)benzamine, which is converted to the diazonium derivative in situ, and subsequently attached to a gold substrate using conventional cathodic electrochemical grafting. Multilayer formation is avoided by the presence of the bulky triisopropylsilyl (TIPS) protected ethynyl group. After removal of the TIPS group by treatment with fluoride, the film, now bearing exposed terminal acetylene moieties, is further functionalised by reaction with 1-iodo-4-acetylthiobenzene using Sonogashira coupling chemistry, to create sites bearing a strongly aurophilic top-contacting group. The success of these surface reactions is confirmed using Raman spectroscopy (gap-mode and SHINERS, employing gold nanoparticles and SiO2 coated gold nanoparticles, respectively). It is shown that such thiolate-modified, diazonium-grafted monolayers are suitable for STM-based molecular junction conductance measurements. (C) 2016 The Authors. Published by Elsevier Ltd.