Quinone-Facilitated Coordinated Bipyrene and Polypyrene on Au(111) by Capture of Gold Adatoms

Precise "bottom-up" synthesis by surface-assisted chemical reaction provides advanced approaches for the fabrication of two-dimensional (2D) robust covalent nanostructures, which are bound to contain defects due to the irreversible properties of covalent bonds. The further introduction of metal-organic coordination interactions possessing self-correction abilities and yielding comparable stabilities would be a strategically advanced supplement for the construction of well-ordered complex covalent networks. In this report, the on-surface synthesis of Au-coordinated bipyrenes and polypyrenes is achieved on Au(111) by a combination of triggering surface-assisted dehalogenative coupling and capture of Au adatoms. The resulting nanostructures are characterized using a scanning tunneling microscope and X-ray photoelectron spectroscopy analysis and further verified by density functional theory calculations. Quinone group functionality present in the pyrene precursor molecules is the key by which the formation of O-Au-O coordination bonds is facilitated, in turn forcing the expulsion of bromine atoms from the thus formed 2D nanostructures.