Constructing low-dimensional covalent assemblies with tailored size and connectivity is challenging yet often key for applications in molecular electronics where optical and electronic properties of the quantum materials are highly structure dependent. We present a versatile approach for building such structures block by block on bilayer sodium chloride (NaCl) films on Cu(111) with the tip of an atomic force microscope, while tracking the structural changes with single-bond resolution. Covalent homo-dimers in cis and trans configurations and homo-/hetero-trimers were selectively synthesized by a sequence of dehalogenation, translational manipulation and intermolecular coupling of halogenated precursors. Further demonstrations of structural build-up include complex bonding motifs, like carbon–iodine–carbon bonds and fused carbon pentagons. This work paves the way for synthesizing elusive covalent nanoarchitectures, studying structural modifications and revealing pathways of intermolecular reactions.

构建具有定制尺寸和连接性的低维共价组件具有挑战性，但对于量子材料的光学和电子特性高度依赖于结构的分子电子学应用来说，这通常是关键。我们提出了一种通用方法，可以用原子力显微镜的尖端在 Cu(111) 上的双层氯化钠 (NaCl) 膜上逐块构建这种结构，同时用单键分辨率跟踪结构变化。顺式和反式共价同源二聚体通过卤化前体的一系列脱卤、平移操作和分子间偶联选择性地合成构型和同源/异源三聚体。结构构建的进一步演示包括复杂的键合基序，如碳-碘-碳键和稠合碳五边形。这项工作为合成难以捉摸的共价纳米结构、研究结构修饰和揭示分子间反应的途径铺平了道路。