Structure Formation and Coupling Reactions of Hexaphenylbenzene and Its Brominated Analog

Authors

Jacob D Teeter, University of Nebraska - LincolnFollow
Paulo S. Costa, University of Nebraska - LincolnFollow
Christoph Dobner, Universität Bayreuth
Mamun Sarker, University of Nebraska - LincolnFollow
Alexander Sinitskii, University of Nebraska - LincolnFollow
Axel Enders, Universität BayreuthFollow

Date of this Version

2021

Citation

ChemPhysChem 2021, 22, 1769– 1773

Comments

© 2021 The Authors. ChemPhysChem published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution License

Abstract

The on-surface coupling of the prototypical precursor molecule for graphene nanoribbon synthesis, 6,11-dibromo-1,2,3,4-tetraphenyltriphenylene (C₄₂Br₂H₂₆, TPTP), and its non-brominated analog hexaphenylbenzene (C₄₂H₃₀, HPB), was investigated on coinage metal substrates as a function of thermal treatment. For HPB, which forms non-covalent 2D monolayers at room temperature, a thermally induced transition of the monolayer’s structure could be achieved by moderate annealing, which is likely driven by π-bond formation. It is found that the dibrominated carbon positions of TPTP do not guide the coupling if the growth occurs on a substrate at temperatures that are sufficient to initiate C􀀀 H bond activation. Instead, similar one-dimensional molecular structures are obtained for both types of precursors, HPB and TPTP.