To explore solvent gating of single-molecule electrical conductance due to solvent-molecule interactions, charge transport through single-molecule junctions with different anchoring groups in various solvent environments was measured by using the mechanically controllable break junction technique. We found that the conductance of single-molecule junctions can be tuned by nearly an order of magnitude by varying the polarity of solvent. Furthermore, gating efficiency due to solvent–molecule interactions was found to be dependent on the choice of the anchor group. Theoretical calculations revealed that the polar solvent shifted the molecular-orbital energies, based on the coupling strength of the anchor groups. For weakly coupled molecular junctions, the polar solvent–molecule interaction was observed to reduce the energy gap between the molecular orbital and the Fermi level of the electrode and shifted the molecular orbitals. This resulted in a more significant gating effect than that of the strongly coupled molecules. This study suggested that solvent–molecule interaction can significantly affect the charge transport through single-molecule junctions.

为了探索由于溶剂-分子相互作用而导致的单分子电导的溶剂门控，使用机械可控断裂连接技术测量了在各种溶剂环境中通过具有不同锚定基团的单分子连接的电荷传输。我们发现，通过改变溶剂的极性，可以将单分子结的电导调节近一个数量级。此外，发现由于溶剂-分子相互作用而产生的门控效率取决于锚定基团的选择。理论计算表明，极性溶剂根据锚定基团的耦合强度改变了分子轨道能量。对于弱耦合分子结，观察到极性溶剂-分子相互作用减少了分子轨道与电极费米能级之间的能隙并移动了分子轨道。这导致比强耦合分子更显着的门控效应。这项研究表明溶剂-分子相互作用可以显着影响通过单分子连接的电荷传输。