Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, 321004, Jinhua, China.
Zhejiang Engineering Laboratory for Green Syntheses and Applications of Fluorine-Containing Specialty Chemicals, Institute of Advanced Fluorine-Containing Materials, Zhejiang Normal University, 321004, Jinhua, China.
Nat Commun. 2023 Jun 9;14(1):3397. doi: 10.1038/s41467-023-39206-w.
The nature of molecule-electrode interface is critical for the integration of atomically precise molecules as functional components into circuits. Herein, we demonstrate that the electric field localized metal cations in outer Helmholtz plane can modulate interfacial Au-carboxyl contacts, realizing a reversible single-molecule switch. STM break junction and I-V measurements show the electrochemical gating of aliphatic and aromatic carboxylic acids have a conductance ON/OFF behavior in electrolyte solution containing metal cations (i.e., Na, K, Mg and Ca), compared to almost no change in conductance without metal cations. In situ Raman spectra reveal strong molecular carboxyl-metal cation coordination at the negatively charged electrode surface, hindering the formation of molecular junctions for electron tunnelling. This work validates the critical role of localized cations in the electric double layer to regulate electron transport at the single-molecule level.
分子-电极界面的性质对于将原子精度的分子作为功能组件集成到电路中至关重要。本文中，我们证明了局域在外亥姆霍兹平面的金属阳离子的电场可以调制界面上的 Au-羧基接触，实现了可逆的单分子开关。STM 断键和 I-V 测量表明，与没有金属阳离子时的电导几乎没有变化相比，在外加金属阳离子（即 Na、K、Mg 和 Ca）的电解质溶液中，脂肪族和芳香族羧酸的电化学门控具有电导 ON/OFF 行为。原位拉曼光谱揭示了在带负电荷的电极表面上强的分子羧基-金属阳离子配位，阻碍了电子隧穿的分子结的形成。这项工作验证了局域化阳离子在外双电层中在单分子水平上调节电子输运的关键作用。
