Institute of Computational and Theoretical Studies & Department of Physics , Hong Kong Baptist University , Hong Kong SAR , China.
Department of Physics and Materials Science , City University of Hong Kong , Hong Kong SAR , China.
ACS Nano. 2018 Mar 27;12(3):3020-3029. doi: 10.1021/acsnano.8b00784. Epub 2018 Feb 26.
While molecular machines play an increasingly significant role in nanoscience research and applications, there remains a shortage of investigations and understanding of the molecular gear (cogwheel), which is an indispensable and fundamental component to drive a larger correlated molecular machine system. Employing ab initio calculations, we investigate model systems consisting of molecules adsorbed on metal or graphene surfaces, ranging from very simple triple-arm gears such as PF and NH to larger multiarm gears based on carbon rings. We explore in detail the transmission of slow rotational motion from one gear to the next by these relatively simple molecules, so as to isolate and reveal the mechanisms of the relevant intermolecular interactions. Several characteristics of molecular gears are discussed, in particular the flexibility of the arms and the slipping and skipping between interlocking arms of adjacent gears, which differ from familiar macroscopic rigid gears. The underlying theoretical concepts suggest strongly that other analogous structures may also exhibit similar behavior which may inspire future exploration in designing large correlated molecular machines.
虽然分子机器在纳米科学研究和应用中扮演着越来越重要的角色，但对于分子齿轮（齿轮）的研究和理解仍然不足，而分子齿轮是驱动更大相关分子机器系统的不可或缺的基本组成部分。我们采用从头算计算方法，研究了由吸附在金属或石墨烯表面上的分子组成的模型体系，这些分子从非常简单的三臂齿轮（如 PF 和 NH）到基于碳环的更大的多臂齿轮不等。我们详细研究了相对简单的分子将缓慢旋转运动从一个齿轮传递到另一个齿轮的过程，从而分离并揭示相关分子间相互作用的机制。我们讨论了分子齿轮的几个特性，特别是臂的灵活性以及相邻齿轮的互锁臂之间的滑动和跳跃，这与常见的宏观刚性齿轮不同。底层理论概念强烈表明，其他类似结构也可能表现出类似的行为，这可能为设计大型相关分子机器的未来探索提供启示。
