Adsorption orientation and STM imaging of meta-benzyne resolved by scanning tunnelling microscopy and ab initio calculations

Dissociative adsorption of doubly substituted benzene molecules leads to a molecule with two missing hydrogen atoms. We use scanning tunnelling microscopy at 5 K and density functional theory to investigate these benzyne molecules on Cu(1 1 1). Benzyne is either imaged as a depression, as a ring-shaped protrusion, or as a circular protrusion at different tunnelling parameters. Submolecular resolution and ab initio calculations give information on the adsorption properties about the in-situ formed biradical species.