A5011386674- Surface Chemistry and Catalysis
- Molecular Junctions and Nanostructures
- Graphene research and applications
- Covalent Organic Framework Applications
- Surface and Thin Film Phenomena
- Nanocluster Synthesis and Applications
- Advanced Chemical Physics Studies
- Supramolecular Self-Assembly in Materials
- Block Copolymer Self-Assembly
- nanoparticles nucleation surface interactions
- Advanced Polymer Synthesis and Characterization
- Synthesis and Properties of Aromatic Compounds
- Advanced Physical and Chemical Molecular Interactions
- Theoretical and Computational Physics
- Force Microscopy Techniques and Applications
- CO2 Reduction Techniques and Catalysts
- Porphyrin and Phthalocyanine Chemistry
- Mesoporous Materials and Catalysis
- 2D Materials and Applications
- Electron and X-Ray Spectroscopy Techniques
- Adhesion, Friction, and Surface Interactions
- Photochromic and Fluorescence Chemistry
- Topological Materials and Phenomena
- Gold and Silver Nanoparticles Synthesis and Applications
- Photonic Crystals and Applications
Institut National de la Recherche Scientifique
2014-2024
Deutsches Museum
2020-2024
Technical University of Munich
2024
Institute of Structure of Matter
2019-2021
Centre National pour la Recherche Scientifique et Technique (CNRST)
2017-2019
Varian Medical Systems (Switzerland)
2017-2019
Abstract On-surface covalent self-assembly of organic molecules is a very promising bottom–up approach for producing atomically controlled nanostructures. Due to their highly tuneable properties, these structures may be used as building blocks in electronic carbon-based molecular devices. Following this idea, here we report on the structure an ordered array poly(para-phenylene) nanowires produced by surface-catalysed dehalogenative reaction. By scanning tunnelling spectroscopy follow...
Surface-confined polymerization via Ullmann coupling is a promising route to create one- and two-dimensional covalent π-conjugated structures, including the bottom-up growth of graphene nanoribbons. Understanding mechanism reaction necessary provide platform for rationally controlling formation these materials. We use fast X-ray photoelectron spectroscopy (XPS) in kinetic measurements epitaxial surface 1,4-dibromobenzene on Cu(110) devise model based mean field rate equations, involving...
Ullmann coupling is the most common approach to form surface-confined one- and two-dimensional conjugated structures from haloaryl derivatives. The dimensions of formed nanostructures can be controlled by number location halogens within molecular precursors. Our study illustrates that type halogen plays an essential role in design, orientation, extent organometallic polymeric nanostructures. We performed a comparative analysis five 1,4-dihalobenzene molecules containing chlorine, bromine,...
Temperature mapping of the different molecular phases tribromoterthienobenzene on (111) coinage metals.
Ullmann coupling or, more generally, dehalogenative aryl-aryl coupling, is one of the most widely exploited chemical reactions to obtain one- and two-dimensional polymers on metal surfaces. It generally described as a two-step reaction: (i) dehalogenation, resulting in formation stable intermediate organometallic phase subsequent (ii) C-C coupling. The topology polymer depends number positions halogen atoms haloaromatic precursor, although its orientation order are determined by structure...
The temporal evolution of the reactant concentrations as measured by XPS for different temperature profiles reveals that debromination organic molecules on Ag(111) is activated Ag adatoms.
Ullmann coupling is a widely used reaction for the on-surface growth of low-dimensional carbon nanomaterials. The irreversible nature this prevents "self-healing" defects, and detailed knowledge its mechanism therefore essential to enable extended ordered structures. However, dynamics polymerization remain largely unexplored, as events occur on timescale faster than conventional scanning probe microscopy imaging frequencies. Here, we reveal these surface using high-speed variable-temperature...
The ability of catecholamines to undergo oxidative self-polymerization provides an attractive route for preparation coatings biotechnology and biomedicine applications. However, efforts toward developing a complete understanding the mechanism that underpins polymerization have been hindered by multiple catechol crosslinking reaction pathways occur during reaction. Scanning tunneling microscopy allows investigation small molecules in reduced-complexity environment, providing important insight...
Two-dimensional conjugated polymers (2DCPs) are an emerging class of materials that exhibit properties similar to graphene yet do not have the limitation zero bandgap. On-surface synthesis provides exceptional control on polymerization reaction, allowing tailoring by choosing suitable monomers. Heteroatom-substituted triangulene 2DCPs constitute a playing ground for such design and predicted graphene-like band structures with high charge mobility characteristic Dirac cones in conduction or...
Abstract To facilitate C−C coupling in on‐surface synthesis on inert surfaces, we devised a radical deposition source (RDS) for the direct of aryl radicals onto arbitrary substrates. Its core piece is heated reactive drift tube through which halogenated precursors are deposited and en route converted into radicals. For proof concept study 4,4′′‐diiodo‐ p ‐terphenyl (DITP) iodine‐passivated metal surfaces. Deposition with RDS at room temperature results highly regular structures comprised...
On-surface Ullmann coupling is an established method for the synthesis of 1D and 2D organic structures. A key limitation to obtaining ordered polymers uncertainty in final structure via random diffusion reactants over substrate, which leads polymorphism defects. Here, a topotactic polymerization on Cu(110) series differently-halogenated para-phenylenes identified, where self-assembled organometallic (OM) diiodobenzene couple directly into single, deterministic product, whereas other...
Quantification of the effect partial dehalogenation on SAMN a bromo-substituted heterotriangulene molecule by comprehensive DFT/MC model.
Investigating two-dimensional (2D) self-assembled structures of biological monomers governed by intermolecular interactions is a prerequisite to understand the self-assembly more complex biomolecular systems. 5,6-Dihydroxyindole carboxylic acid (DHICA) one building blocks eumelanin - an irregular heteropolymer and most common form melanin which has potential applications in organic electronics bioelectronics. By means scanning tunneling microscopy, density functional theory Monte Carlo...
Abstract While surface‐confined Ullmann‐type coupling has been widely investigated for its potential to produce π‐conjugated polymers with unique properties, the pathway of this reaction in presence adsorbed oxygen yet be explored. Here, effect adsorption between different steps polymerization is studied, revealing an unexpected transformation 1D organometallic (OM) chains 2D OM networks by annealing, rather than polymer obtained on pristine surfaces. Characterization scanning tunneling...
The two-dimensional (2D) surface-directed self-assembly of dibenzonitrile diacetylene (DBDA) on Ag(111) under ultrahigh vacuum (UHV) conditions was investigated by combining scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS) and theoretical simulations based density functional theory (DFT) calculations. molecule consists two benzonitrile groups (-C6H4-C[triple bond, length as m-dash]N) each side a (-C[triple m-dash]C-C[triple m-dash]C-) backbone. terminating nitrile...
Regular and robust 2D conjugated organogold networks with anthra-tetrathiophene repeat units are synthesized by debrominative coupling on iodine-passivated Au(111). Dynamic error correction becomes feasibly through iodine-induced bond reversibility.
Abstract Zur Realisierung von C‐C‐Kupplungen in der Oberflächensynthese auf inerten Oberflächen haben wir eine Radikal‐Abscheidungs‐Quelle (RAQ) für die direkte Abscheidung Aryl Radikalen beliebige Substrate entwickelt. Das Herzstück ist ein beheiztes reaktives Drift‐Rohr, durch das halogenierte Vorläufer abgeschieden und dabei en route Radikale umgewandelt werden. Den Machbarkeitsbeweis erbringen mit 4,4′′‐Diiod‐ p ‐terphenyl (DITP)‐Vorläufern Iod‐passivierten Metall‐Oberflächen. Aus RAQ...
The development of widely applicable methods for the synthesis C-C-bonded nanostructures on inert and insulating surfaces is a challenging yet rewarding milestone in field on-surface synthesis. This would enable studies nearly unperturbed covalent with unique electronic properties as graphene nanoribbons (GNR) π-conjugated 2D polymers. prevalent Ullmann-type couplings are almost exclusively carried out metal to lower temperature required initial dehalogenation well below desorption...