Abstract：
Molecular gearing systems are technomimetic nanoscale analogues to complex geared machinery in the macroscopic world. They are defined as systems incorporating intermeshed movable parts which perform correlated rotational motions by mechanical engagement. Only recently, new methods to actively drive molecular gearing motions instead of relying on passive thermal activation have been developed. Further progress in this endeavor will pave the way for unidirectional molecular gearing devices with a distinct type of molecular machine awaiting its realization. Within this work an essential step towards this goal is achieved by evidencing directional biases for the light-induced rotations in our molecular photogear system. Using a custom-designed LED-coupled chiral cryo-HPLC setup for the in situ irradiation of enantiomeric analytes, an intrinsic selectivity for clockwise or counterclockwise rotations was elucidated experimentally. Significant directional biases in the photogearing processes and light-induced single bond rotations (SBRs) are observed for our photogear with directional preferences of up to 4.8 : 1. Harnessing these effects will allow to rationally design and construct a fully directional molecular gearing motor in the future.
摘要：
分子齿轮系统是宏观世界中复杂齿轮机械的技术模拟纳米级类似物，同样被定义为包含通过机械接合执行相关旋转运动的相互啮合元素的系统。只是最近,已经开发了主动驱动分子齿轮运动而不是依靠被动热激活的新方法。这项工作的进一步进展将为单向分子齿轮装置铺平道路，该装置具有等待实现的独特类型的分子机器。在这项工作中，通过证明分子光凝胶系统1中光诱导旋转的方向偏差，实现了实现这一目标的重要步骤。使用定制设计的LED耦合手性低温HPLC设置对映体分析物的原位辐照，通过实验阐明了顺时针或逆时针旋转的固有选择性。对于光凝胶1，观察到光凝胶过程和光诱导的单键旋转（SBR）中的显着方向偏差，方向偏好高达4.8：1。利用这些效应将允许在未来合理地设计和构造完全定向的分子齿轮传动马达。
