金属-有机配位键模板法制备表面共价纳米结构

通过有机分子间的表面共价反应合成低维共价有机纳米结构是表面物理化学领域近年来的研究热点。此方法合成的有机纳米结构具有原子级的精确性，呈现出丰富的纳米尺寸相关的电子、自旋特性，有着巨大的应用前景。但是，由于大多数共价反应不具有选择性，反应过程也不可逆，导致了合成的结构往往包含过多缺陷或反应副产物，严重阻碍其在功能纳米材料和器件中的应用。与之相反的是，籍由配位键优异的自选择、自辨识和成键可逆性，表面配位自组装已经成功地用于构筑大面积有序的表面纳米结构。该项目拟将配位键引入到表面共价反应体系中，利用超高真空扫描隧道显微镜等表征手段，考察配位键的构型、键能、配位数等特性对表面共价反应的热力学动力学的控制，实现反应路径的模板诱导，最终合成特定的表面共价纳米结构。可控生成的表面共价纳米结构在结构和化学上的新颖特性（掺杂、多孔、周期性）有望能为人们设计合成新型功能性有机纳米材料和器件提供实验基础。

In the past decades, bottom-up construction of the low-dimensional covalent organic nanostructures, via on-surface reactions between organic molecular building blocks, has attracted intense interests. The on-surface synthesis can provide single-atomic precision with the resultant nanostructures, which exhibit various electronic/spintronic novelties, and demonstrate great application potentials. Nevertheless, covalent bonds generally are non-selective and non-reversible, leading to the on-surface synthesized structures being of many defects and side-products, hindering their applications. In contrast, owing to the excellent self-selection, self-recognition and reversibility of the metal-organic coordination bonds, the on-surface coordination self-assembly has been well established to direct the regular arrangements of molecules at large scales. Our project is to introduce the coordination bonding motifs into the covalent coupling systems, exploring the template effect of the coordinative bonding to the covalent coupling. We will combine the scanning tunneling microscopy and other surface-sensitive techniques and theoretical simulations, to investigate the control over the reaction pathways of covalent couplings based on the template effect of coordination bonds that are of various conformations, bond energy and coordination numbers. This approach may result in a variety of covalent organic nanostructures with tunable doping or periodicity. Investigation of the structural and chemical novelties may provide insightful information for the synthesis and design of new functional nanomaterials and nanodevices.