“自下而上”的纳米结构制备法是一种在原子或分子水平上构筑纳米结构的方法;相比于“自上而下”的蚀刻技术,其可实现更小尺寸的半导体器件的制备。因此,这种“自下而上”制备法将是纳米技术未来的重发展方向。然而,其中一个存在己久的关键问题是如何实现对所构筑的纳米拓扑结构进行精确控制。此文综述了近期关于如何调控由表面乌尔曼反应合成的纳米材料拓扑结构的研究。其中包括以下三个方面:首先,利用纳米结构与衬底晶格参数之间的匹配关系控制金属有机链的形状;其次,利用超栅格或者超分子模板对长链进行有效剪裁;最后,利用纳米结构与衬底之间对称性的匹配来调控环状和链状产物的形成。另外,我们对寻求普适性模板以调控更广泛类型的纳米材料的拓扑结构进行了展望。
The future of nanotechnology lies in the "bottom up" approach, which aims at building nanostructures at an atomic or molecular level so as to minimize the sizes of chips and other nano-devices. However, one of the long-term unresolved issues for "bottom up" nanotechnology is the precise control of the topologies of fabricated nanostructures. In this contibution, we review recent studies with regard to the control of the topologies of nanostructures formed via the on-surface UIImann reaction of haloarenes. This includes three aspects: control of the shape of the organometallic chain via lattice matching between the adsorbate nanostructure and the substrate; tailoring the chains by employing super-gratings or supramolecular templates; and steering the covalent ring-chain competition in the reaction of precursors towards ring formation through adsorbate-substrate symmetry matching. Further, we present future directions for the development of more general templates for the regulation of the topologies of a broader range of nanostructures.