Not So Innocent After All: Interfacial Chemistry Determines Charge-Transport Efficiency in Single-Molecule Junctions
Not So Innocent After All: Interfacial Chemistry Determines Charge-Transport Efficiency in Single-Molecule Junctions
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DOI：
10.1002/anie.202302150
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发表时间：
2023-05-04
影响因子：
16.6
通讯作者：
Sangtarash, Sara
中科院分区：
文献类型：
--
作者：
Daaoub, Abdalghani;Morris, James M. F.;Sangtarash, Sara
分子电子学的大部分研究都集中在改变分子线的主干来调整整个结的电学性质。然而，经常被忽视的是，将分子锚定在金属电极上的基团的化学结构会影响整个系统的电子结构，从而影响其电导率。我们合成了接受电子的二硫磷氧化物衍生物，并制作了它们的单分子结。我们发现锚基团对电荷传输效率有显著影响：在我们的研究中，缺电子的4-吡啶触点抑制电导，而富电子的4-硫代异唑末端促进有效传输。我们的计算表明，这是由于电荷分布的微小变化，在电极界面探测。我们的发现为有效的分子结设计提供了一个框架，特别是对具有强吸电子/给电子主干的化合物有价值。
Most studies in molecular electronics focus on altering the molecular wire backbone to tune the electrical properties of the whole junction. However, it is often overlooked that the chemical structure of the groups anchoring the molecule to the metallic electrodes influences the electronic structure of the whole system and, therefore, its conductance. We synthesised electron-accepting dithienophosphole oxide derivatives and fabricated their single-molecule junctions. We found that the anchor group has a dramatic effect on charge-transport efficiency: in our case, electron-deficient 4-pyridyl contacts suppress conductance, while electron-rich 4-thioanisole termini promote efficient transport. Our calculations show that this is due to minute changes in charge distribution, probed at the electrode interface. Our findings provide a framework for efficient molecular junction design, especially valuable for compounds with strong electron withdrawing/donating backbones.