The Education Ministry Key Lab of Resource Chemistry, Joint International Research Laboratory of Resource Chemistry, Ministry of Education, Shanghai Key Laboratory of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai 200234, China.
The State Key Laboratory of Refractories and Metallurgy, the Institute of Advanced Materials and Nanotechnology, Wuhan University of Science and Technology, Wuhan, Hubei 430081, China.
Nano Lett. 2021 Dec 22;21(24):10333-10340. doi: 10.1021/acs.nanolett.1c03565. Epub 2021 Dec 7.
Here, six phenanthrene (the smallest arm-chair graphene nanoribbon) derivatives with dithiomethyl substitutions at different positions as the anchoring groups were synthesized. Scanning tunneling microscopy break junction technique was used to measure their single molecule conductances between gold electrodes, which showed a difference as much as 20-fold in the range of ∼10 G to ∼10 G following the trend of G > G > G > G > G > G. DFT calculations agree well with this measured trend and indicate that the single molecule conductances are a combination of energy alignment, electronic coupling, and quantum effects. This significant regio- and steric effect on the single molecule conductance of phenanthrene model molecules shows the complexity in the practice of graphene nanoribbons as building blocks for future carbon-based electronics in one hand but also provides good conductance tunability on the other hand.
在这里，我们合成了六个具有不同位置二硫甲基取代作为锚固基团的菲（最小的扶手椅石墨烯纳米带）衍生物。使用扫描隧道显微镜断键技术在金电极之间测量它们的单分子电导率，在 ∼10 G 到 ∼10 G 的范围内，遵循 G > G > G > G > G > G 的趋势，差异高达 20 倍。DFT 计算与这一测量趋势吻合良好，并表明单分子电导率是能量排列、电子耦合和量子效应的组合。这种对菲模型分子单分子电导的显著区域和空间位阻效应表明，石墨烯纳米带作为未来基于碳的电子学的构建块在实践中具有复杂性，但另一方面也提供了良好的电导可调性。
