Unusual Scaffold Rearrangement in Polyaromatic Hydrocarbons Driven by Concerted Action of Single Gold Atoms on a Gold Surface.

Chemical transformation of polyaromatic hydrocarbon (PAH) molecules following different reaction strategies has always been the focus of organic synthesis. In this work, we report the synthesis of a PAH molecule, formation of which consists of an unusual C-C bond cleavage accompanied by a complex π-conjugated molecular scaffold rearrangement. We demonstrate that the complex chemical transformation is steered by concerted motion of individual Au gold atoms on a supporting Au(111) surface. This observation underpins the importance of single-atom catalysis mediated by adatoms in on-surface synthesis as well as catalytic activity of single Au atoms facilitating cleavage of covalent carbon bonds.