Real-Time Imaging of On-Surface Ullmann Polymerization Reveals an Inhibiting Effect of Adatoms
Ullmann coupling is a widely used reaction for the on-surface growth of low-dimensional carbon nanomaterials. The irreversible nature of this reaction prevents the "self-healing" of defects, and a detailed knowledge of its mechanism is therefore essential to enable the growth of extended ordered structures. However, the dynamics of the Ullmann polymerization remain largely unexplored, as coupling events occur on a timescale faster than conventional scanning probe microscopy imaging frequencies. Here, we reveal the dynamics of these surface events using high-speed variable-temperature scanning tunneling microscopy (STM) (10 frames per second). Performing the measurements at the onset reaction temperatures provides an unprecedented description of the evolution of organometallic (OM) and covalent surface species during the Ullmann polymerization of <i>para</i>-dibromobenzene on Cu(110). Our results demonstrate the existence of an intermediate OM phase with Cu adatoms that inhibits the polymerization. These observations now complete the picture of the pathways of on-surface Ullmann polymerization, which includes the complex interplay of the phenylene moieties and metal atoms. Our work demonstrates the unique capability of high-speed STM to capture the dynamics of molecular self-assembly and coupling.
Authors
- Stefano Fabris (ORCID: https://orcid.org/0000-0003-2562-8788)
- Mirco Panighel (ORCID: https://orcid.org/0000-0001-8413-5196)
- Gianluca Galeotti (ORCID: https://orcid.org/0000-0002-9992-1971)
- Cristina Africh (ORCID: https://orcid.org/0000-0002-1922-2557)
- Oliver MacLean (ORCID: https://orcid.org/0000-0003-3632-5010)
- Dominik Dettmann (ORCID: https://orcid.org/0000-0002-4310-7866)
- Dmitrii F. Perepichka (ORCID: https://orcid.org/0000-0003-2233-416X)
- G. Contini (ORCID: https://orcid.org/0000-0002-6248-9716)
- Federico Rosei (ORCID: https://orcid.org/0000-0001-8479-6955)
- Matteo Farnesi Camellone (ORCID: https://orcid.org/0000-0001-9180-0115)
- Tarnjit Kaur Johal
- Navathej Preetha Genesh (ORCID: https://orcid.org/0000-0003-2899-5495)
Institutions
- University of Rome Tor Vergata (IT)
- Scuola Internazionale Superiore di Studi Avanzati (IT)
- University of Trieste (IT)
- Jilin Normal University (CN)
- AREA Science Park (IT)
- Institut National de la Recherche Scientifique (CA)
- Istituto Officina dei Materiali (IT)
- Institute of Structure of Matter (IT)
- National Research Council (IT)
- McGill University (CA)
Publication Details
- Journal
- Journal of the American Chemical Society
- Published
- 2024-08-21
- DOI
- https://doi.org/10.1021/jacs.4c06994
- Citations
- 6
- Primary Topic
- Surface Chemistry and Catalysis
- Type
- article
- Field-Weighted Citation Impact
- 1.11
Funders
- Compute Canada
- Government of Ontario
- European Commission
- University of Toronto
- Ministero degli Affari Esteri e della Cooperazione Internazionale
- Regione Lazio
- Alliance de recherche numérique du Canada
- Horizon 2020 Framework Programme
- Natural Sciences and Engineering Research Council of Canada
- Fonds de recherche du Québec – Nature et technologies
- FP7 International Cooperation