分子柔性侧链对Au(111)表面超分子配位自组装的调控 Tuning the Supramolecular Coordination Self-Assembly on Au(111) Surface by Molecular Flexible Side Chains

在本文中，我们借助超高真空–扫描隧道显微镜(UHV-STM)，研究了分子柔性侧链(flexible side chain)对金属表面超分子配位自组装的调控作用。有机分子L由带吡啶基(pyridyl(py))的咔唑骨架和一条十四烷基侧链构成。在预先沉积了Cu的Au(111)表面上，分子L可以通过py-Cu-py配位方式连接成链。STM研究显示，室温下有机分子L的十四烷基链由于自身热能而在衬底表面高速摆动。实验发现这种由侧链的摆动引起的空间位阻(steric hindrance)效应能够调控金属有机配位分子链的间距。本实验对于理解和利用柔性侧链在表面自组装结构中的调控作用具有重要的意义。 In this paper, we studied the effect of molecular flexible side chains on the supramolecular coor-dination self-assembly on metal surface, by using an ultra-high vacuum-scanning tunneling mi-croscope (UHV-STM). The organic molecule L is composed of a carbazole skeleton with two pyridyl group and a tetradecyl side chain. On the Au (111) surface with predeposited Cu atoms, the molecules L coordinate with Cu via the pyridyl terminals into chains, while. STM study shows that the tetradecyl side chain of the molecule L oscillates on the surface due to its thermal energy at room temperature. Analysis based on high-resolution images reveals that the steric hindrance caused by the side chain oscillation regulates the arrangement of the assembled metal-organic coordination chains. This experiment is of great significance for understanding and using the flexible side chains in the surface self-assembly structure.