title: Fusing tetrapyrroles to graphene edges by surface-assisted covalent coupling.
abstract: Surface-assisted covalent linking of precursor molecules enables the fabrication of low-dimensional nanostructures, which include graphene nanoribbons. One approach to building functional multicomponent systems involves the lateral anchoring of organic heteromolecules to graphene. Here we demonstrate the dehydrogenative coupling of single porphines to graphene edges on the same metal substrate as used for graphene synthesis. The covalent linkages are visualized by scanning probe techniques with submolecular resolution, which directly reveals bonding motifs and electronic features. Distinct configurations are identified that can be steered towards entities predominantly fused to graphene edges through two pyrrole rings by thermal annealing. Furthermore, we succeeded in the concomitant metallation of the macrocycle with substrate atoms and the axial ligation of adducts. Such processes combined with graphene-nanostructure synthesis has the potential to create complex materials systems with tunable functionalities.
authors.affiliation: Physik-Department E20, Technische Universität München, James-Franck-Straße 1, D-85748 Garching, Germany.|Institute for Advanced Study, Technische Universität München, Lichtenbergstraße 2a, D-85748 Garching, Germany.
authors.forename: Yuanqin
authors.initials: Y
authors.lastname: He
authors.affiliation: Physik-Department E20, Technische Universität München, James-Franck-Straße 1, D-85748 Garching, Germany.
authors.forename: Manuela
authors.initials: M
authors.lastname: Garnica
authors.affiliation: Physik-Department E20, Technische Universität München, James-Franck-Straße 1, D-85748 Garching, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Bischoff
authors.affiliation: Physik-Department E20, Technische Universität München, James-Franck-Straße 1, D-85748 Garching, Germany.
authors.forename: Jacob
authors.initials: J
authors.lastname: Ducke
authors.affiliation: Department of Chemistry, UMR ENS-CNRS-UPMC 8640, Ecole Normale Supérieure, F-75005 Paris, France.
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Bocquet
authors.affiliation: Institute for Advanced Study, Technische Universität München, Lichtenbergstraße 2a, D-85748 Garching, Germany.|Department of Physics, University of South Florida, Tampa, Florida 33620, USA.
authors.forename: Matthias
authors.initials: M
authors.lastname: Batzill
authors.affiliation: Physik-Department E20, Technische Universität München, James-Franck-Straße 1, D-85748 Garching, Germany.
authors.forename: Willi
authors.initials: W
authors.lastname: Auwärter
authors.affiliation: Physik-Department E20, Technische Universität München, James-Franck-Straße 1, D-85748 Garching, Germany.
authors.forename: Johannes V
authors.initials: JV
authors.lastname: Barth