title: Dehalogenation and coupling of a polycyclic hydrocarbon on an atomically thin insulator.
abstract: Catalytic activity is of pivotal relevance in enabling efficient and selective synthesis processes. Recently, covalent coupling reactions catalyzed by solid metal surfaces opened the rapidly evolving field of on-surface chemical synthesis. Tailored molecular precursors in conjunction with the catalytic activity of the metal substrate allow the synthesis of novel, technologically highly relevant materials such as atomically precise graphene nanoribbons. However, the reaction path on the metal substrate remains unclear in most cases, and the intriguing question is how a specific atomic configuration between reactant and catalyst controls the reaction processes. In this study, we cover the metal substrate with a monolayer of hexagonal boron nitride (h-BN), reducing the reactivity of the metal, and gain unique access to atomistic details during the activation of a polyphenylene precursor by sequential dehalogenation and the subsequent coupling to extended oligomers. We use scanning tunneling microscopy and density functional theory to reveal a reaction site anisotropy, induced by the registry mismatch between the precursor and the nanostructured h-BN monolayer.
authors.affiliation: nanotech@surfaces Laboratory, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Dienel
authors.forename: Jaime
authors.initials: J
authors.lastname: Gómez-Díaz
authors.forename: Ari P
authors.initials: AP
authors.lastname: Seitsonen
authors.forename: Roland
authors.initials: R
authors.lastname: Widmer
authors.forename: Marcella
authors.initials: M
authors.lastname: Iannuzzi
authors.forename: Kevin
authors.initials: K
authors.lastname: Radican
authors.forename: Hermann
authors.initials: H
authors.lastname: Sachdev
authors.forename: Klaus
authors.initials: K
authors.lastname: Müllen
authors.forename: Jürg
authors.initials: J
authors.lastname: Hutter
authors.forename: Oliver
authors.initials: O
authors.lastname: Gröning