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4 results on '"Seddigheh Nikipar"'

1. Tuning the conductance of a molecular wire by the interplay of donor and acceptor units

Author

Tim Erdmann, Dmitry Skidin, Florian Günther, Sibylle Gemming, Justus Krüger, Seddigheh Nikipar, Frank Eisenhut, Christian Joachim, Dmitry A. Ryndyk, Gianaurelio Cuniberti, Francesca Moresco, Anton Kiriy, Brigitte Voit, Max Bergmann Center of Biomaterials Dresden, Center for Advancing Electronics in Dresden (CFAED), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Leibniz-Institut für Polymerforschung Dresden e.V. (IPF), Leibniz Association, Institute of Ion Beam Physics and Materials Research [Dresden], Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Chemnitz University of Technology / Technische Universität Chemnitz, Universität Bremen, Groupe NanoSciences (CEMES-GNS), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Dresden Center for Computational Materials Science, Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, molecular electronics, band structure, STM, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Molecular physics, law.invention, Molecular wire, chemistry.chemical_compound, law, molecular wire, Thiophene, General Materials Science, Electronic band structure, Spectroscopy, Quantum tunnelling, [PHYS]Physics [physics], DA polymer, Conductance, 021001 nanoscience & nanotechnology, density-functional, Acceptor, 0104 chemical sciences, chemistry, Scanning tunneling microscope, 0210 nano-technology, conductance, donor-acceptor polymer
Abstract

International audience; We investigate the conductance of optimized donor–acceptor–donor molecular wires obtained by on-surface synthesis on the Au(111) surface. A careful balance between acceptors and donors is achieved using a diketopyrrolopyrrole acceptor and two thiophene donors per unit along the wire. Scanning tunneling microscopy imaging, spectroscopy, and conductance measurements done by pulling a single molecular wire at one end are presented. We show that the conductance of the obtained wires is among the highest reported so far in a tunneling transport regime, with an inverse decay length of 0.17 Å−1. Using complex band structure calculations, different donor and acceptor groups are discussed, showing how a balanced combination of donor and acceptor units along the wire can further minimize the decay of the tunneling current with length.

Published
2018
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2. On-surface synthesis of nitrogen-doped nanographenes with 5-7 membered rings

Author

Reinhard Berger, Marcus Richter, Frank Eisenhut, Gianaurelio Cuniberti, Francesca Moresco, Seddigheh Nikipar, Justus Krüger, Dmitry A. Ryndyk, Xinliang Feng, and Dmitry Skidin

Subjects
Surface (mathematics), Condensed Matter - Materials Science, Materials science, 010405 organic chemistry, Scanning tunneling spectroscopy, Metals and Alloys, Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, Nitrogen doped, General Chemistry, 010402 general chemistry, 01 natural sciences, Catalysis, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, law.invention, Crystallography, law, Materials Chemistry, Ceramics and Composites, Scanning tunneling microscope, Electronic properties
Abstract

We report on the formation of nitrogen-doped nanographenes containing five- and seven-membered rings by thermally induced cyclodehydrogenation on the Au(111) surface. Using scanning tunneling microscopy and supported by calculations, we investigated the structure of the precursor and targets, as well as of intermediates. Scanning tunneling spectroscopy shows that the electronic properties of the target nanographenes are strongly influenced by the additional formation of non-hexagonal rings.

Published
2020
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3. Hexacene generated on passivated silicon

Author

Gianaurelio Cuniberti, Justus Krüger, Frank Eisenhut, Diego Peña, Seddigheh Nikipar, Dmitry Skidin, Dmitry A. Ryndyk, Jose M. Alonso, Enrique Guitián, Francesca Moresco, and Dolores Pérez

Subjects
Materials science, Silicon, Spintronics, Dangling bond, chemistry.chemical_element, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Hexacene, 0104 chemical sciences, law.invention, chemistry.chemical_compound, Chemical bond, chemistry, law, Chemical physics, Molecule, General Materials Science, Density functional theory, Scanning tunneling microscope, 0210 nano-technology
Abstract

On-surface synthesis represents a successful strategy to obtain designed molecular structures on an ultra-clean metal substrate. While metal surfaces are known to favor adsorption, diffusion, and chemical bonding between molecular groups, on-surface synthesis on non-metallic substrates would allow the electrical decoupling of the resulting molecule from the surface, favoring application to electronics and spintronics. Here, we demonstrate the on-surface generation of hexacene by surface-assisted reduction on a H-passivated Si(001) surface. The reaction, observed by scanning tunneling microscopy and spectroscopy, is probably driven by the formation of Si-O complexes at dangling bond defects. Supported by density functional theory calculations, we investigate the interaction of hexacene with the passivated silicon surface, and with single silicon dangling bonds.

Published
2018

4. On-Surface Annulation Reaction Cascade for the Selective Synthesis of Diindenopyrene

Author

Andreas Viertel, Seddigheh Nikipar, Francesca Moresco, Dmitry A. Ryndyk, Gianaurelio Cuniberti, Justus Krüger, Stefan Hecht, Frank Eisenhut, Christian Joachim, Thomas Lehmann, Dmitry Skidin, Max Bergmann Center of Biomaterials Dresden, Humboldt State University (HSU), IRIS Adlershof, Berlin, Germany, Groupe NanoSciences (CEMES-GNS), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics], Annulation, Reaction mechanism, General Engineering, General Physics and Astronomy, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Ring (chemistry), Photochemistry, 01 natural sciences, 0104 chemical sciences, 3. Good health, law.invention, chemistry.chemical_compound, chemistry, law, Molecule, Pyrene, General Materials Science, Scanning tunneling microscope, 0210 nano-technology, Spectroscopy, Benzene
Abstract

cited By 0; International audience; We investigated the thermally induced on-surface cyclization of 4,10-bis(2′-bromo-4′-methylphenyl)-1,3-dimethylpyrene to form the previously unknown, nonalternant polyaromatic hydrocarbon diindeno[1,2,3-cd:1′,2′,3′-mn]pyrene on Au(111) using scanning tunneling microscopy and spectroscopy. The observed unimolecular reaction involves thermally induced debromination followed by selective ring closure to fuse the neighboring benzene moieties via a five-membered ring. The structure of the product has been verified experimentally as well as theoretically. Our results demonstrate that on-surface reactions give rise to unusual chemical reactivities and selectivities and provide access to nonalternant polyaromatic molecules.

Published
2017
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