Dresden 2017 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 45: Organic-Inorganic Hybrid Systems and Organic Films

O 45.12: Poster

Dienstag, 21. März 2017, 18:30–20:30, P1A

Topologically Different Aromatic Isomers on Metal Surfaces: A Molecular Model System for 5-7 Defects in Graphene — •Katharina K. Greulich¹, Benedikt P. Klein¹, Nadine van der Heijden¹, Claudio K. Krug², Stefan R. Kachel¹, Maik Schöniger¹, Phil Rosenow¹, Martin Schmid¹, Ralf Tonner¹, Ingmar Swart², and J. Michael Gottfried¹ — ¹Fachbereich Chemie, Philipps-Universität Marburg, Germany — ²Debye Institute for Nanomaterial Science, Utrecht University, The Netherlands

While conjugated systems with alternant topologies and their interaction with metal surfaces have been subject to intensive investigation, much less is known about their non-alternant isomers. A conjugated system with non-alternant topology occurs in the 5-7 defects of graphene. As a molecular model system for these defects, we investigated azulene and compared it to naphthalene as a model for the regular 6-6 motif. Both molecules were studied on Cu(111) and Ag(111) surfaces with PES, NEXAFS, TPD, nc-AFM, STM and periodic DFT calculations. The non-alternant topology causes non-uniform charge distribution and more localized frontier orbitals, resulting in a much stronger and more localized interaction with both metal surfaces. Manifestations of the stronger interaction of the non-alternant molecule with the surface include interfacial charge transfer and substantial in-plane and out-of-plane deformations. The latter result from the donation of electron density into the LUMO of the non-alternant molecule.