Inter- and Intramolecular On-Surface Synthesis of Porphyrin-Based Nanostructures on Au(111) and Cu(111)
(2025) In ACS Applied Nano Materials 8(24). p.12608-12618- Abstract
Surface-confined synthesis provides alternative reaction pathways to those utilized within solution-phase chemistry and offers a route to extended molecular architectures with nanoscale dimensions and fascinating magnetic, electronic, and catalytic properties. However, these reaction pathways can be complex multistep processes, containing multiple reactive intermediates. Optimizing the selectivity and efficiency of such synthetic routes should be underpinned by detailed mechanistic insight, which requires submolecular spatial resolution in combination with details of chemical evolution throughout the reaction process. A key challenge is the application of an experimental methodology that allows in-depth study of multistep reactions.... (More)
Surface-confined synthesis provides alternative reaction pathways to those utilized within solution-phase chemistry and offers a route to extended molecular architectures with nanoscale dimensions and fascinating magnetic, electronic, and catalytic properties. However, these reaction pathways can be complex multistep processes, containing multiple reactive intermediates. Optimizing the selectivity and efficiency of such synthetic routes should be underpinned by detailed mechanistic insight, which requires submolecular spatial resolution in combination with details of chemical evolution throughout the reaction process. A key challenge is the application of an experimental methodology that allows in-depth study of multistep reactions. Here, we combine the spatial resolution of scanning tunneling microscopy with temperature-programmed photoelectron spectroscopies and present a comprehensive characterization of a multistep on-surface reaction utilizing a brominated porphyrin species. The porphyrin species employed is a highly functionalizable “molecular building block” from which nanostructured materials can be built, and within this work we identify key differences between the reaction on Cu(111) and Au(111). Intermolecular Ullmann-type coupling as well as intramolecular ring-closing and self-metalation are observed: specifically, on Au(111) we characterize self-metalation within covalently coupled assemblies of ring-closed TPP. Our results highlight the differing reactivity of Au(111) and Cu(111) and the strong influence of the substrate upon the reaction pathway and preferred products, and we provide spectroscopic and topographical characterization for all reaction steps.
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- author
- Frampton, Eleanor S. LU ; Clarke, Michael ; Edmondson, Matthew ; Gray, Ailish ; Bradford, Jonathan ; Warwick, Liv ; Pearce, Nicholas ; Champness, Neil R. and Saywell, Alex
- organization
- publishing date
- 2025-06-20
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Near-Edge X-ray Adsorption Fine Structure (NEXAFS), On-Surface Synthesis, Photoelectron Spectroscopy (PES), Porphyrins, Scanning Tunneling Microscopy (STM), Temperature-Programmed X-ray Photoelectron Spectroscopy (TP-XPS)
- in
- ACS Applied Nano Materials
- volume
- 8
- issue
- 24
- pages
- 11 pages
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- pmid:40567904
- scopus:105008141950
- ISSN
- 2574-0970
- DOI
- 10.1021/acsanm.5c01525
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2025 The Authors. Published by American Chemical Society.
- id
- b7eb49a4-91d2-45ab-b5ca-f15d7a5cd46d
- date added to LUP
- 2025-12-16 13:04:36
- date last changed
- 2025-12-17 03:00:20
@article{b7eb49a4-91d2-45ab-b5ca-f15d7a5cd46d,
abstract = {{<p>Surface-confined synthesis provides alternative reaction pathways to those utilized within solution-phase chemistry and offers a route to extended molecular architectures with nanoscale dimensions and fascinating magnetic, electronic, and catalytic properties. However, these reaction pathways can be complex multistep processes, containing multiple reactive intermediates. Optimizing the selectivity and efficiency of such synthetic routes should be underpinned by detailed mechanistic insight, which requires submolecular spatial resolution in combination with details of chemical evolution throughout the reaction process. A key challenge is the application of an experimental methodology that allows in-depth study of multistep reactions. Here, we combine the spatial resolution of scanning tunneling microscopy with temperature-programmed photoelectron spectroscopies and present a comprehensive characterization of a multistep on-surface reaction utilizing a brominated porphyrin species. The porphyrin species employed is a highly functionalizable “molecular building block” from which nanostructured materials can be built, and within this work we identify key differences between the reaction on Cu(111) and Au(111). Intermolecular Ullmann-type coupling as well as intramolecular ring-closing and self-metalation are observed: specifically, on Au(111) we characterize self-metalation within covalently coupled assemblies of ring-closed TPP. Our results highlight the differing reactivity of Au(111) and Cu(111) and the strong influence of the substrate upon the reaction pathway and preferred products, and we provide spectroscopic and topographical characterization for all reaction steps.</p>}},
author = {{Frampton, Eleanor S. and Clarke, Michael and Edmondson, Matthew and Gray, Ailish and Bradford, Jonathan and Warwick, Liv and Pearce, Nicholas and Champness, Neil R. and Saywell, Alex}},
issn = {{2574-0970}},
keywords = {{Near-Edge X-ray Adsorption Fine Structure (NEXAFS); On-Surface Synthesis; Photoelectron Spectroscopy (PES); Porphyrins; Scanning Tunneling Microscopy (STM); Temperature-Programmed X-ray Photoelectron Spectroscopy (TP-XPS)}},
language = {{eng}},
month = {{06}},
number = {{24}},
pages = {{12608--12618}},
publisher = {{The American Chemical Society (ACS)}},
series = {{ACS Applied Nano Materials}},
title = {{Inter- and Intramolecular On-Surface Synthesis of Porphyrin-Based Nanostructures on Au(111) and Cu(111)}},
url = {{http://dx.doi.org/10.1021/acsanm.5c01525}},
doi = {{10.1021/acsanm.5c01525}},
volume = {{8}},
year = {{2025}},
}