Single molecule vs. large area design of molecular electronic devices incorporating an efficient 2-aminepyridine double anchoring group
Single molecule vs. large area design of molecular electronic devices incorporating an efficient 2-aminepyridine double anchoring group
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DOI：
10.1039/c9nr05662a
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发表时间：
2019-09-14
期刊：
影响因子：
6.7
通讯作者：
Cea, P.
中科院分区：
文献类型：
--
作者：
Herrer, L.;Ismael, A.;Cea, P.
当分子通过末端锚基团与外部电极结合时，后者在确定所得分子结的电导率方面至关重要。在这里，我们探索了具有双齿锚基团的分子，即4，4 '-（1，4-亚苯基双（乙炔-2，1-二基））双（吡啶-2-胺），在大面积器件和单分子水平上的电学性质。我们发现单分子和单分子的电导率分别为0.6 × 10（-4）G（0）和1.2 × 10（-4）G（0）。这些值比具有相同分子骨架的单齿材料所报道的值高大约一个数量级。理论和实验相结合，了解具有这种新的多齿锚组的单层和单分子电结的电导。我们的研究结果表明，该分子有一个30度的倾斜角相对于正常的表面在单层，而在单分子结的断裂长度发生的分子有一个倾斜角估计为40度，这将占他们的电导值的差异，每个分子。双齿2-氨基吡啶锚作为接触基团受到普遍关注，因为该末端官能化芳环有利于吸附物与金属接触的结合，从而导致电导值提高。
When a molecule is bound to external electrodes by terminal anchor groups, the latter are of paramount importance in determining the electrical conductance of the resulting molecular junction. Here we explore the electrical properties of a molecule with bidentate anchor groups, namely 4,4 '-(1,4-phenylenebis(ethyne-2,1-diyl))bis(pyridin-2-amine), in both large area devices and at the single molecule level. We find an electrical conductance of 0.6 x 10(-4)G(0) and 1.2 x 10(-4)G(0) for the monolayer and for the single molecule, respectively. These values are approximately one order of magnitude higher than those reported for monodentate materials having the same molecular skeleton. A combination of theory and experiments is employed to understand the conductance of monolayer and single molecule electrical junctions featuring this new multidentate anchor group. Our results demonstrate that the molecule has a tilt angle of 30 degrees with respect to the normal to the surface in the monolayer, while the break-off length in the single molecule junction occurs for molecules having a tilt angle estimated as 40 degrees, which would account for the difference in their conductance values per molecule. The bidentate 2-aminepyridine anchor is of general interest as a contact group, since this terminal functionalized aromatic ring favours binding of the adsorbate to the metal contact resulting in enhanced conductance values.