Site Selectivityof the σ‑Bond Metathesison a Persilylated Decaethynyldiphenyl

The selective functionalization of organic molecules is a cornerstone in chemistry, enabling the design and assembly of tailored molecular architectures. The controlled, site-selective functionalization of the same chemical groups within one molecule is challenging and hinders the synthesis of specific organic nanostructures, especially in on-surface chemistry. Here, using low-temperature scanning tunneling microscopy and density functional theory calculation, the site-selective desilylation at <i>para</i>, <i>meta</i>, and <i>ortho</i> positions of persilylated decaethynyldiphenyl in the σ-bond metathesis reaction with 2,6-naphthalenedicarboxylic acid on the Ag(111) surface is reported. The site selectivity observed stems from the varying bulky silyl configurations at different molecular positions, leading to distinct reaction barriers in the σ-bond metathesis. These findings provide insight into the on-surface site-selective activation of large aromatic compounds.