One of the most appealing topics in the study of metal-organic networks is the growth mechanism. However, its study is still considered a significant challenge. Herein, using scanning tunneling microscopy, the growth mechanisms of metal-alkynyl networks on Ag(111) and Au(111) surfaces were investigated at the atomic scale. During the reaction of 1,3,5-tris(chloroethynyl)benzene on Ag(111), honeycomb Ag-alkynyl networks formed at 393 K, and only short chain intermediates were observed. By contrast, the same precursor formed honeycomb Au-alkynyl networks on Au(111) at 503 K. Progression annealing led to a stepwise evolution process, in which the sequential activation of three Cl-alkynyl bonds led to the formation of dimers, zigzag chains, and novel chiral networks as the intermediates. Moreover, density functional theory calculations indicate that chlorine atoms are crucial in assisting the breakage of metal-alkynyl bonds to form Cl-metal-alkynyl, which guarantees the reversibility of the break/formation equilibration as the key to forming regular large-scale organometallic networks.

中文翻译：

---

表面金属-炔基网络逐步生长机制的原子级可视化

金属有机网络研究中最吸引人的主题之一是生长机制。然而，它的研究仍然被认为是一个重大挑战。在这里，使用扫描隧道显微镜，在原子尺度上研究了 Ag(111) 和 Au(111) 表面上金属-炔基网络的生长机制。在 1,3,5-三（氯乙炔基）苯在 Ag(111) 上的反应过程中，蜂窝状 Ag-炔基网络在 393 K 下形成，仅观察到短链中间体。相比之下，相同的前体在 503 K 下在 Au(111) 上形成蜂窝状 Au-炔基网络。 渐进退火导致逐步进化过程，其中三个 Cl-炔基键的顺序激活导致形成二聚体，锯齿形链，以及作为中间体的新型手性网络。而且，