Stabilizing edge fluorination in graphene nanoribbons
Panighel, Mirco (Institut Català de Nanociència i Nanotecnologia)
Peña, Diego (Universidade de Santiago de Compostela. Departamento de Química Orgánica)
Brandimarte Mendonça, Pedro (Donostia International Physics Center)
Moreno, Cesar (Institut Català de Nanociència i Nanotecnologia)
Garcia-Lekue, Aran (Ikerbasque)
Vilas-Varela, Manuel (Universidade de Santiago de Compostela. Departamento de Química Orgánica)
Rey, Dulce (Universidade de Santiago de Compostela. Departamento de Química Orgánica)
Sauthier, Guillaume (Institut Català de Nanociència i Nanotecnologia)
Ceballos, Gustavo (Institut Català de Nanociència i Nanotecnologia)
Mugarza, Aitor (Institut Català de Nanociència i Nanotecnologia)

Date:	2020
Abstract:	The on-surface synthesis of edge-functionalized graphene nanoribbons (GNRs) is challenged by the stability of the functional groups throughout the thermal reaction steps of the synthetic pathway. Edge fluorination is a particularly critical case in which the interaction with the catalytic substrate and intermediate products can induce the complete cleavage of the otherwise strong C-F bonds before the formation of the GNR. Here, we demonstrate how a rational design of the precursor can stabilize the functional group, enabling the synthesis of edge-fluorinated GNRs. The survival of the functionalization is demonstrated by tracking the structural and chemical transformations occurring at each reaction step with complementary X-ray photoelectron spectroscopy and scanning tunneling microscopy measurements. In contrast to previous attempts, we find that the C-F bond survives the cyclodehydrogenation of the intermediate polymers, leaving a thermal window where GNRs withhold more than 80% of the fluorine atoms. We attribute this enhanced stability of the C-F bond to the particular structure of our precursor, which prevents the cleavage of the C-F bond by avoiding interaction with the residual hydrogen originated in the cyclodehydrogenation. This structural protection of the linking bond could be implemented in the synthesis of other sp2-functionalized GNRs.
Grants:	European Commission 863098 European Commission 600385 Ministerio de Economía y Competitividad SEV-2017-0706 Agencia Estatal de Investigación FIS2017-83780-P Ministerio de Economía y Competitividad MAT2016-78293-C6
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Language:	Anglès
Document:	Article ; recerca ; Versió sotmesa a revisió
Subject:	Graphene nanoribbons ; On-surface synthesis ; Edge-functionalization ; Fluorination ; Scanning tunneling microscopy ; Density functional theory ; Self-assembly
Published in:	ACS nano, Vol. 14, issue 9 (Sep. 2020) , p. 11120-11129, ISSN 1936-086X

DOI: 10.1021/acsnano.0c01837

Preprint 30 p, 2.2 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles