Liu Xiaolin, Yang Hao, Harb Hassan, Samajdar Rajarshi, Woods Toby J, Lin Oliver, Chen Qian, Romo Adolfo I B, Rodríguez-López Joaquín, Assary Rajeev S, Moore Jeffrey S, Schroeder Charles M
Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, IL, USA.
Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, IL, USA.
Nat Chem. 2024 Nov;16(11):1772-1780. doi: 10.1038/s41557-024-01619-5. Epub 2024 Aug 26.
Molecular electronic devices require precise control over the flow of current in single molecules. However, the electron transport properties of single molecules critically depend on dynamic molecular conformations in nanoscale junctions. Here we report a unique strategy for controlling molecular conductance using shape-persistent molecules. Chemically diverse, charged ladder molecules, synthesized via a one-pot multicomponent ladderization strategy, show a molecular conductance (d[log(G/G)]/dx ≈ -0.1 nm) that is nearly independent of junction displacement, in stark contrast to the nanogap-dependent conductance (d[log(G/G)]/dx ≈ -7 nm) observed for non-ladder analogues. Ladder molecules show an unusually narrow distribution of molecular conductance during dynamic junction displacement, which is attributed to the shape-persistent backbone and restricted rotation of terminal anchor groups. These principles are further extended to a butterfly-like molecule, thereby demonstrating the strategy's generality for achieving gap-independent conductance. Overall, our work provides important avenues for controlling molecular conductance using shape-persistent molecules.
分子电子器件需要对单分子中的电流流动进行精确控制。然而，单分子的电子传输特性严重依赖于纳米级结中的动态分子构象。在此，我们报告了一种使用形状持久分子控制分子电导的独特策略。通过一锅多组分阶梯化策略合成的化学性质多样的带电阶梯分子，其分子电导（d[log(G/G)]/dx ≈ -0.1 nm）几乎与结位移无关，这与非阶梯类似物所观察到的依赖于纳米间隙的电导（d[log(G/G)]/dx ≈ -7 nm）形成鲜明对比。在动态结位移过程中，阶梯分子的分子电导分布异常狭窄，这归因于形状持久的主链和末端锚定基团的受限旋转。这些原理进一步扩展到一种蝴蝶状分子，从而证明了该策略实现与间隙无关电导的通用性。总体而言，我们的工作为使用形状持久分子控制分子电导提供了重要途径。
