Au Yeung Kwan Ho, Kühne Tim, Eisenhut Frank, Kleinwächter Michael, Gisbert Yohan, Robles Roberto, Lorente Nicolas, Cuniberti Gianaurelio, Joachim Christian, Rapenne Gwénaël, Kammerer Claire, Moresco Francesca
CEMES, Université de Toulouse, CNRS, 31055 Toulouse, France.
Centro de Fisica de Materiales CFM/MPC (CSIC-UPV/EHU), 20018 Donostia-San Sebastián, Spain.
J Phys Chem Lett. 2020 Aug 20;11(16):6892-6899. doi: 10.1021/acs.jpclett.0c01747. Epub 2020 Aug 11.
The realization of a train of molecule-gears working under the tip of a scanning tunneling microscope (STM) requires a stable anchor of each molecule to the metal surface. Such an anchor can be promoted by a radical state of the molecule induced by a dissociation reaction. Our results, rationalized by density functional theory calculations, reveal that such an open radical state at the core of star-shaped pentaphenylcyclopentadiene (PPCP) favors anchoring. Furthermore, to allow the transmission of motion by STM manipulation, the molecule-gears should be equipped with specific groups facilitating the tip-molecule interactions. In our case, a -butyl group positioned at one tooth end of the gear benefits both the tip-induced manipulation and the monitoring of rotation. With this optimized molecule, we achieve reproducible and stepwise rotations of the single gears and transmit rotations for up to three interlocked units.
要实现一系列在扫描隧道显微镜（STM）针尖下工作的分子齿轮，需要每个分子在金属表面有稳定的固定。由解离反应诱导的分子自由基态可促进这种固定。我们的结果经密度泛函理论计算得到合理解释，结果表明，星形五苯基环戊二烯（PPCP）核心处的这种开放自由基态有利于固定。此外，为了通过STM操纵实现运动传递，分子齿轮应配备有助于针尖 - 分子相互作用的特定基团。在我们的例子中，位于齿轮一个齿端的丁基基团有利于针尖诱导的操纵和旋转监测。利用这种优化的分子，我们实现了单个齿轮可重复的逐步旋转，并将旋转传递到多达三个互锁单元。
