×

Indexed by

Reaction pathway towards 7-atom-wide armchair graphene nanoribbon formation and identification of intermediate species on Au(111)

Sebastian Thussing1, Sebastian Flade1, Kristjan Eimre2, Carlo A. Pignedoli2*, Roman Fasel2,3*, Peter Jakob1

1 Fachbereich Physik und Wissenschaftliches Zentrum für Materialwissenschaften, Philipps-Universität Marburg, Renthof 5, 35032 Marburg, Germany

2 Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Switzerland

3 Department of Chemistry and Biochemistry, University of Bern, 3012 Bern, Switzerland

* Corresponding authors emails: carlo.pignedoli@empa.ch, roman.fasel@empa.ch
DOI10.24435/materialscloud:wy-bn [version v1]

Publication date: Oct 14, 2020

How to cite this record

Sebastian Thussing, Sebastian Flade, Kristjan Eimre, Carlo A. Pignedoli, Roman Fasel, Peter Jakob, Reaction pathway towards 7-atom-wide armchair graphene nanoribbon formation and identification of intermediate species on Au(111), Materials Cloud Archive 2020.120 (2020), doi: 10.24435/materialscloud:wy-bn.

Description

In this record we provide data supporitng our recent results discussed in the characterization of the fabrication process of graphene nanoribbons. The prototypical surface reaction of 10,10′-dibromo-9,9′-bianthryl (DBBA) toward the seven-atom-wide armchair graphene nanoribbon (7-AGNR) on the Au(111) surface has been investigated by means of vibrational spectroscopy, thermal desorption spectroscopy, and density functional theory. Specifically, a direct correlation between annealing temperature and the formation of various intermediate species is derived. By comparison of IR spectra with results from DFT calculations, an identification of reaction intermediates has been achieved, allowing for a precise mapping of individual reaction steps. Thereby, we identify a prior unknown partially dehalogenated and strongly tilted DBBA* monoradical species (DBBA-1Br) after mild annealing (380–450 K). This inclined adsorption geometry stabilizes the second Br atom, preventing full dehalogenation. According to our calculations, dimerization of DBBA-1Br reverses this inclination and provides an efficient way to enable abstraction of the second Br atom and initiate polyanthracene chain formation by means of DBBA* addition. As a competitive process to dimerization, a small number of the DBBA* monoradicals recombine with previously released bromine atoms, leading to associative DBBA desorption. In the course of thermal processing, hydrogen release signals planarization of the twisted anthracene units of DBBA by means of cyclodehydrogenation and formation of the final 7-AGNR. Based on the results of this work, an in-depth understanding of the on-surface synthesis of 7-AGNR on Au(111), starting with a DBBA molecular precursor, has been attained.

Materials Cloud sections using this data

No Explore or Discover sections associated with this archive record.

Files

File name Size Description
ReadMe.yaml
MD5md5:228e84bddc30c4ae3f25860ca848c6d7
1.5 KiB ReadMe file in yaml format listing all files contained in the record
geometry_optimizations.aiida
MD5md5:073327e5f445d0ec0f39d688ed6e82e9
30.8 MiB Archive of calculation nodes for calculations performed with AiiDA
data.tgz
MD5md5:3949feb17b108c1012a8d5293571290d
117.6 MiB Archive file containing data for all calculations not performed with AiiDA

License

Files and data are licensed under the terms of the following license: Creative Commons Attribution 4.0 International.
Metadata, except for email addresses, are licensed under the Creative Commons Attribution Share-Alike 4.0 International license.

Keywords

graphene nanoribbons MARVEL/DD3 SNSF CSCS DFG on surface synthesis IR spectroscopy

Version history:

2020.120 (version v1) [This version] Oct 14, 2020 DOI10.24435/materialscloud:wy-bn