Tracking and removing Br during the on-surface synthesis of a graphene nanoribbon
2015 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 119, no 1, 486-493 p.Article in journal (Refereed) Published
The fabrication of graphene nanoribbons (GNRs) requires a high degree of precision due to the sensitivity of the electronic structure on the edge shape. Using Br-substituted molecular precursors, this atomic precision can be achieved in a thermally induced two-step reaction following Br dissociation on a Au(111) surface. Using DFT, we find evidence that the Br atoms are bound to the intermediate polyanthrylene chains. We employ temperature-programmed desorption to demonstrate the associative desorption of HBr and molecular hydrogen during the final cyclodehydrogenation step of the reaction. Both processes are found to have similar activation barriers. Furthermore, we are able to remove Br atoms from the polyanthrylene chains by providing molecular hydrogen. The subsequent formation of GNR via a cyclodehydrogenation demonstrates that Br does not influence this part of the overall reaction.
Place, publisher, year, edition, pages
2015. Vol. 119, no 1, 486-493 p.
IdentifiersURN: urn:nbn:se:liu:diva-114462DOI: 10.1021/jp5106218ISI: 000347744700053OAI: oai:DiVA.org:liu-114462DiVA: diva2:789921
We thank Jorg Meyer of the University of Leiden for fruitful discussions and gratefully acknowledge funding by the German Research Foundation (DFG) through collaborative research center SFB658 and the Project TE479/3-1 as well as by the Freie Universitat Berlin through the FocusArea Nanoscale. Computational resources were allocated at the National Supercomputer Centre, Sweden, through SNIC.2015-02-202015-02-202015-03-02