The dehalogenative homocoupling of DBTP molecules on Au(111) surface has been investigated at a single molecular level by scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. The length and morphology of the carbon-carbon coupling chain are adjusted by stepwise thermal excitation. Gradual annealing of the sample at 323 and 353 K promotes the dehalogenative homocoupling, resulting in the formation of oligomer and long straight chains that branch out or form combs. Such straight chains show an obvious zipper-like double-chain structure when annealed at 373 K. Our results show that Br-H bonds between straight chains play a stabilizing role in the zipper structure. During further annealing to a maximum of 453 K, both dehalogenative homocoupling and cross-coupling occur between the chains. The number of monomers in the molecular chains formed at 453 K is 16–20, accounting for the largest proportion.

通过扫描隧道显微镜 (STM) 和密度泛函理论 (DFT) 计算，在单分子水平上研究了 Au(111) 表面上 DBTP 分子的脱卤自偶联。通过逐步热激发来调节碳-碳偶联链的长度和形态。样品在 323 和 353 K 下逐渐退火可促进脱卤自偶联，从而形成低聚物和分支或形成梳状的长直链。当在373 K退火时，这种直链表现出明显的拉链状双链结构。我们的结果表明，直链之间的Br-H键在拉链结构中起着稳定作用。在进一步退火至最高 453 K 的过程中，链之间会发生脱卤自偶联和交叉偶联。