基于充电态和氢键构筑表面安装的超分子马达

分子马达是指把外界的化学能，光能或电能转换为定向转动的纳米机器。在超分子马达中，定子和转子之间不存在共价键，而是以力的形式相连接，因而具有很低的转动能垒。另一方面，自然界中的分子马达都工作在界面附近，因此研究表面安装的分子马达更具有应用前景。一个重要的问题是，能否制造出一种表面安装的的超分子马达？如果能的话，定子和转子靠什么力相结合？用什么方式和能量来驱动转子的转动？本项目将围绕这些问题，在半金属和绝缘表面上制备乙醇超分子马达。首先，利用STM针尖施加电压脉冲给乙醇团簇充电，使其作为马达的定子；利用氢键自组装生长乙醇分子链，使其作为马达的转子；定子和转子通过静电吸引相连接。我们可以利用STM针尖输出的非弹性隧穿电子来驱动分子链的转动。利用隧穿电流-时间谱和分子动力学模拟研究马达的转动频率与转动能垒之间的关系，从分子尺度上理解超分子马达的运转机制，为设计和制造新一代分子马达提供新的思路。

Molecular motors are nano-scale machines that can convert external chemical, light, or electrical energies into controlled mechanical movement. In supramolecular motors, the rotator and stator are connected through mechanic interaction, and thus reveal very low energy barrier. On the other hand, in nature, motors operate at interface, surface-mounted motors offer the most potential in application. One question arises that is it possible to fabricate surface-mounted supramolecular motor? If yes, what kind of force exists between the rotator and stator? Furthermore, what kind of energy and means will be used by the supramolecular motor? In present proposal, we will address these questions by fabricating ethanol supramolecular motors on semimetal and insulating surface. First, we apply voltage pulses through a STM tip to charge the individual ethanol clusters, serving as a stator. Then the self-assembled ethanol chains driven by hydrogen bond will be sued as rotator. It is the electrostatic interaction that connect the rotator and stator. The inelastic tunneling electrons from STM tip will be used to drive the rotation of rotator. Moreover, we will used the I-t spectrum and molecule dynamic simulation to reveal the relation between the rotation rate and energy barrier, and understand the mechanism of supramolecular motor at the molecule level, and provide a new way for designing and constructing new type of motor.