Chiaravalloti Franco, Gross Leo, Rieder Karl-Heinz, Stojkovic Sladjana M, Gourdon André, Joachim Christian, Moresco Francesca
Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany.
Nat Mater. 2007 Jan;6(1):30-3. doi: 10.1038/nmat1802. Epub 2006 Dec 10.
Molecular machines, and in particular molecular motors with synthetic molecular structures and fuelled by external light, voltage or chemical conversions, have recently been reported. Most of these experiments are carried out in solution with a large ensemble of molecules and without access to one molecule at a time, a key point for future use of single molecular machines with an atomic scale precision. Therefore, to experiment on a single molecule-machine, this molecule has to be adsorbed on a surface, imaged and manipulated with the tip of a scanning tunnelling microscope (STM). A few experiments of this type have described molecular mechanisms in which a rotational movement of a single molecule is involved. However, until now, only uncontrolled rotations or indirect signatures of a rotation have been reported. In this work, we present a molecular rack-and-pinion device for which an STM tip drives a single pinion molecule at low temperature. The pinion is a 1.8-nm-diameter molecule functioning as a six-toothed wheel interlocked at the edge of a self-assembled molecular island acting as a rack. We monitor the rotation of the pinion molecule tooth by tooth along the rack by a chemical tag attached to one of its cogs.
最近有报道称出现了分子机器，特别是具有合成分子结构并由外部光、电压或化学转化提供能量的分子马达。这些实验大多是在含有大量分子的溶液中进行的，无法一次获取单个分子，而这对于未来使用具有原子尺度精度的单分子机器至关重要。因此，为了对单个分子机器进行实验，该分子必须吸附在表面上，用扫描隧道显微镜（STM）的针尖进行成像和操纵。这类实验中的一些已经描述了涉及单个分子旋转运动的分子机制。然而，到目前为止，只报道了不受控制的旋转或旋转的间接特征。在这项工作中，我们展示了一种分子齿条齿轮装置，在低温下，STM针尖驱动单个小齿轮分子。小齿轮是一个直径为1.8纳米的分子，其作用类似于一个六齿齿轮，在作为齿条的自组装分子岛的边缘处相互锁定。我们通过附着在其一个齿上的化学标签，逐个监测小齿轮分子沿着齿条的旋转。
