1
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Wisman DL, Kim H, Kim C, Morris TW, Lee D, Tait SL. Variations in Complementary Hydrogen Bonds Direct Assembly Patterns of Isosteric Polyheteroaromatics at Surfaces. Chemistry 2021; 27:13887-13893. [PMID: 34232531 DOI: 10.1002/chem.202101611] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Indexed: 11/12/2022]
Abstract
Intermolecular interactions guide self-assembly on the surface. Precise control over these interactions by rational design of the molecule should allow fine control over the self-assembly patterns. Functional groups installed for electronic modulation often induce significant changes in the molecular dimensions, thereby disrupting the original assembly pattern. To overcome this challenge, we have employed a family of isosteric phenazine derivatives, DHP, DAP, and DBQD, to investigate the impacts of hydrogen bonding on two-dimensional molecular self-assembly. While these molecules are similar in size and chemical composition, the strength and directionality of hydrogen bonding differ significantly depending on the chemical structure of donor-acceptor pairs and prototropic tautomerization from positional isomerism. Scanning tunneling microscopy (STM) characterization of the assembled structures on Ag(111), Au(111), and Cu(100) surfaces revealed that minimal changes in molecular structure have a profound impact on the self-assembly patterns. While DHP exhibits highly ordered and robust assemblies, DAP and DBQD show either spatially confined or ill-defined assemblies. In conjunction with hydrogen bonding, prototropic tautomerism is a potent strategy to modulate molecular 2D lattices on surfaces.
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Affiliation(s)
- David L Wisman
- Department of Chemistry, Indiana University, Bloomington, Indiana, 47405, USA.,NAVSEA Crane, Crane, Indiana, 47522, USA
| | - Heechan Kim
- Department of Chemistry, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Korea
| | - Chungryeol Kim
- Department of Chemistry, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Korea
| | - Tobias W Morris
- Department of Chemistry, Indiana University, Bloomington, Indiana, 47405, USA
| | - Dongwhan Lee
- Department of Chemistry, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Korea
| | - Steven L Tait
- Department of Chemistry, Indiana University, Bloomington, Indiana, 47405, USA
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2
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Rothe K, Mehler A, Néel N, Kröger J. Scanning tunneling microscopy and spectroscopy of rubrene on clean and graphene-covered metal surfaces. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2020; 11:1157-1167. [PMID: 32821640 PMCID: PMC7418095 DOI: 10.3762/bjnano.11.100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 07/23/2020] [Indexed: 06/11/2023]
Abstract
Rubrene (C42H28) was adsorbed with submonolayer coverage on Pt(111), Au(111), and graphene-covered Pt(111). Adsorption phases and vibronic properties of C42H28 consistently reflect the progressive reduction of the molecule-substrate hybridization. Separate C42H28 clusters are observed on Pt(111) as well as broad molecular resonances. On Au(111) and graphene-covered Pt(111) compact molecular islands with similar unit cells of the superstructure characterize the adsorption phase. The highest occupied molecular orbital of C42H28 on Au(111) exhibits weak vibronic progression while unoccupied molecular resonances appear with a broad line shape. In contrast, vibronic subbands are present for both frontier orbitals of C42H28 on graphene. They are due to different molecular vibrational quanta with distinct Huang-Rhys factors.
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Affiliation(s)
- Karl Rothe
- Institut für Physik, Technische Universität Ilmenau, D-98693 Ilmenau, Germany
| | - Alexander Mehler
- Institut für Physik, Technische Universität Ilmenau, D-98693 Ilmenau, Germany
| | - Nicolas Néel
- Institut für Physik, Technische Universität Ilmenau, D-98693 Ilmenau, Germany
| | - Jörg Kröger
- Institut für Physik, Technische Universität Ilmenau, D-98693 Ilmenau, Germany
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3
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van Buel R, Spitzer D, Berac CM, van der Schoot P, Besenius P, Jabbari-Farouji S. Supramolecular copolymers predominated by alternating order: Theory and application. J Chem Phys 2019; 151:014902. [PMID: 31272178 DOI: 10.1063/1.5097577] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
We investigate the copolymerization behavior of a two-component system into quasilinear self-assemblies under conditions that interspecies binding is favored over identical species binding. The theoretical framework is based on a coarse-grained self-assembled Ising model with nearest neighbor interactions. In Ising language, such conditions correspond to the antiferromagnetic case giving rise to copolymers with predominantly alternating configurations. In the strong coupling limit, we show that the maximum fraction of polymerized material and the average length of strictly alternating copolymers depend on the stoichiometric ratio and the activation free energy of the more abundant species. They are substantially reduced when the stoichiometric ratio noticeably differs from unity. Moreover, for stoichiometric ratios close to unity, the copolymerization critical concentration is remarkably lower than the homopolymerization critical concentration of either species. We further analyze the polymerization behavior for a finite and negative coupling constant and characterize the composition of supramolecular copolymers. Our theoretical insights rationalize experimental results of supramolecular polymerization of oppositely charged monomeric species in aqueous solutions.
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Affiliation(s)
- Reinier van Buel
- Institute of Physics, Johannes Gutenberg-University, Staudingerweg 7-9, 55128 Mainz, Germany
| | - Daniel Spitzer
- Institute of Organic Chemistry, Johannes Gutenberg-University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Christian Marijan Berac
- Institute of Organic Chemistry, Johannes Gutenberg-University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Paul van der Schoot
- Theory of Polymer and Soft Matter Group, Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Pol Besenius
- Institute of Organic Chemistry, Johannes Gutenberg-University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Sara Jabbari-Farouji
- Institute of Physics, Johannes Gutenberg-University, Staudingerweg 7-9, 55128 Mainz, Germany
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4
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Cui D, Ebrahimi M, Macleod JM, Rosei F. Template-Driven Dense Packing of Pentagonal Molecules in Monolayer Films. NANO LETTERS 2018; 18:7570-7575. [PMID: 30403353 DOI: 10.1021/acs.nanolett.8b03126] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The integration of molecules with irregular shape into a long-range, dense and periodic lattice represents a unique challenge for the fabrication of engineered molecular scale architectures. The tiling of pentagonal molecules on a two-dimensional (2D) plane can be used as a proof-of-principle investigation to overcome this problem because basic geometry dictates that a 2D surface cannot be filled with a periodic arrangement of pentagons, a fundamental limitation that suggests that pentagonal molecules may not be suitable as building blocks for dense films. However, here we show that the 2D covalent organic framework (COF) known as COF-1 can direct the growth of pentagonal guest molecules as dense crystalline films at the solution/solid interface. We find that the pentagonal molecule corannulene adsorbs at two different sites on the COF-1 lattice, and that multiple molecules can adsorb into well-defined clusters patterned by the COF. Two types of these dense periodic packing motifs lead to a five-fold symmetry reduction compatible with translational symmetry, one of which gives an unprecedented high molecular density of 2.12 molecules/nm2.
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Affiliation(s)
- Daling Cui
- Centre Énergie, Matériaux et Télécommunications , Institut National de la Recherche Scientifique , 1650 Boulevard Lionel-Boulet , Varennes , Québec J3X 1S2 , Canada
| | - Maryam Ebrahimi
- Centre Énergie, Matériaux et Télécommunications , Institut National de la Recherche Scientifique , 1650 Boulevard Lionel-Boulet , Varennes , Québec J3X 1S2 , Canada
- Physics Department E20 , Technical University of Munich James-Franck-Strasse1 , D-85748 Garching , Germany
| | - Jennifer M Macleod
- Centre Énergie, Matériaux et Télécommunications , Institut National de la Recherche Scientifique , 1650 Boulevard Lionel-Boulet , Varennes , Québec J3X 1S2 , Canada
- School of Chemistry, Physics, and Mechanical Engineering , Queensland University of Technology , Brisbane , 4000 QLD Australia
| | - Federico Rosei
- Centre Énergie, Matériaux et Télécommunications , Institut National de la Recherche Scientifique , 1650 Boulevard Lionel-Boulet , Varennes , Québec J3X 1S2 , Canada
- Institute of Fundamental and Frontier Science , University of Electronic Science and Technology of China , Chengdu 610054 People's Republic of China
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5
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Neff JL, Richter A, Söngen H, Venturini C, Gourdon A, Bechstein R, Kühnle A. Generic nature of long-range repulsion mechanism on a bulk insulator? Faraday Discuss 2017; 204:419-428. [PMID: 28766624 DOI: 10.1039/c7fd00089h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Dynamic atomic force microscopy measurements are reported that provide evidence for the presence of long-range repulsion in molecular self-assembly on a bulk insulator surface. We present the structures formed from four different benzoic acid derivatives on the (10.4) cleavage plane of calcite kept in ultra-high vacuum. These molecules have in common that they self-assemble into molecular stripes when deposited onto the surface held at room temperature. For all molecules tested, a detailed analysis of the stripe-to-stripe distance distribution reveals a clear deviation from what would be expected for randomly placed, non-interacting stripes (i.e., geometric distribution). When excluding kinetic effects during growth, this result gives evidence for a long-range repulsion mechanism acting during the assembly of these stripes. The fact that this finding is robust against changes in the molecular structure indicates a generic nature of the observed mechanism, implying a ubiquitous origin such as electrostatic repulsion. Finally, we discuss parameters that might affect the unambiguous observation of this generic repulsion under specific experimental conditions.
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Affiliation(s)
- J L Neff
- Institute of Physical Chemistry, Johannes Gutenberg University Mainz, 55099 Mainz, Germany.
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6
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Xia H, Fu H, Zhang Y, Shih KC, Ren Y, Anuganti M, Nieh MP, Cheng J, Lin Y. Supramolecular Assembly of Comb-like Macromolecules Induced by Chemical Reactions that Modulate the Macromolecular Interactions In Situ. J Am Chem Soc 2017; 139:11106-11116. [DOI: 10.1021/jacs.7b04986] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
| | | | - Yanfeng Zhang
- Department
of Materials Science and Engineering, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | | | | | | | | | - Jianjun Cheng
- Department
of Materials Science and Engineering, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
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7
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Della Pia A, Riello M, Stassen D, Jones TS, Bonifazi D, De Vita A, Costantini G. Two-dimensional core-shell donor-acceptor assemblies at metal-organic interfaces promoted by surface-mediated charge transfer. NANOSCALE 2016; 8:19004-19013. [PMID: 27808341 DOI: 10.1039/c6nr06527a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Organic charge transfer (CT) complexes obtained by combining molecular electron donors and acceptors have attracted much interest due to their potential applications in organic opto-electronic devices. In order to work, these systems must have an electronic matching - the highest occupied molecular orbital (HOMO) of the donor must couple with the lowest unoccupied molecular orbital (LUMO) of the acceptor - and a structural matching, so as to allow direct intermolecular CT. Here it is shown that, when molecules are adsorbed on a metal surface, novel molecular organizations driven by surface-mediated CT can appear that have no counterpart in condensed phase non-covalent assemblies of donor and acceptor molecules. By means of scanning tunneling microscopy and spectroscopy it is demonstrated that the electronic and self-assembly properties of an electron acceptor molecule can change dramatically in the presence of an additional molecular species with marked electron donor character, leading to the formation of unprecedented core-shell assemblies. DFT and classical force-field simulations reveal that this is a consequence of charge transfer from the donor to the acceptor molecules mediated by the metallic substrate.
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Affiliation(s)
- A Della Pia
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK.
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8
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Jeon S, Doak PW, Sumpter BG, Ganesh P, Maksymovych P. Thermodynamic Control of Two-Dimensional Molecular Ionic Nanostructures on Metal Surfaces. ACS NANO 2016; 10:7821-7829. [PMID: 27458890 DOI: 10.1021/acsnano.6b03492] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Bulk molecular ionic solids exhibit fascinating electronic properties, including electron correlations, phase transitions, and superconducting ground states. In contrast, few of these phenomena have been observed in low-dimensional molecular structures, including thin films, nanoparticles, and molecular blends, not in the least because most of such structures have been composed of nearly closed-shell molecules. It is therefore desirable to develop low-dimensional ionic molecular structures that can capture potential applications. Here, we present detailed analysis of monolayer-thick structures of the canonical TTF-TCNQ (tetrathiafulvalene 7,7,8,8-tetracyanoquinodimethane) system grown on low-index gold and silver surfaces. The most distinctive property of the epitaxial growth is the wide abundance of stable TTF/TCNQ ratios, in sharp contrast to the predominance of a 1:1 ratio in the bulk. We propose the existence of the surface phase diagram that controls the structures of TTF-TCNQ on the surfaces and demonstrate phase transitions that occur upon progressively increasing the density of TCNQ while keeping the surface coverage of TTF fixed. Based on direct observations, we propose the binding motif behind the stable phases and infer the dominant interactions that enable the existence of the rich spectrum of surface structures. Finally, we also show that the surface phase diagram will control the epitaxy beyond monolayer coverage. Multiplicity of stable surface structures, the corollary rich phase diagram, and the corresponding phase transitions present an interesting opportunity for low-dimensional molecular systems, particularly if some of the electronic properties of the bulk can be preserved or modified in the surface phases.
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Affiliation(s)
- Seokmin Jeon
- Center for Nanophase Materials Sciences and ‡Computer Science & Mathematics Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Peter W Doak
- Center for Nanophase Materials Sciences and ‡Computer Science & Mathematics Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Bobby G Sumpter
- Center for Nanophase Materials Sciences and ‡Computer Science & Mathematics Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Panchapakesan Ganesh
- Center for Nanophase Materials Sciences and ‡Computer Science & Mathematics Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Petro Maksymovych
- Center for Nanophase Materials Sciences and ‡Computer Science & Mathematics Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
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9
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Della Pia A, Riello M, Lawrence J, Stassen D, Jones TS, Bonifazi D, De Vita A, Costantini G. Two-Dimensional Ketone-Driven Metal-Organic Coordination on Cu(111). Chemistry 2016; 22:8105-12. [PMID: 27071489 PMCID: PMC5074249 DOI: 10.1002/chem.201600368] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Indexed: 12/02/2022]
Abstract
Two-dimensional metal-organic nanostructures based on the binding of ketone groups and metal atoms were fabricated by depositing pyrene-4,5,9,10-tetraone (PTO) molecules on a Cu(111) surface. The strongly electronegative ketone moieties bind to either copper adatoms from the substrate or codeposited iron atoms. In the former case, scanning tunnelling microscopy images reveal the development of an extended metal-organic supramolecular structure. Each copper adatom coordinates to two ketone ligands of two neighbouring PTO molecules, forming chains that are linked together into large islands through secondary van der Waals interactions. Deposition of iron atoms leads to a transformation of this assembly resulting from the substitution of the metal centres. Density functional theory calculations reveal that the driving force for the metal substitution is primarily determined by the strength of the ketone-metal bond, which is higher for Fe than for Cu. This second class of nanostructures displays a structural dependence on the rate of iron deposition.
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Affiliation(s)
- Ada Della Pia
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK
| | - Massimo Riello
- Department of Physics, King's College London, Strand, London, WC2R 2LS, UK
| | - James Lawrence
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK
| | - Daphne Stassen
- Namur Research College (NARC) and Department of Chemistry, University of Namur (UNamur), 5000, Belgium
| | - Tim S Jones
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK
| | - Davide Bonifazi
- Namur Research College (NARC) and Department of Chemistry, University of Namur (UNamur), 5000, Belgium.
- School of Chemistry, Cardiff University, Park Place, CF10 3AT, Cardiff, UK.
| | - Alessandro De Vita
- Department of Physics, King's College London, Strand, London, WC2R 2LS, UK.
| | - Giovanni Costantini
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK.
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10
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11
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Sun H, Ryno S, Zhong C, Ravva MK, Sun Z, Körzdörfer T, Brédas JL. Ionization Energies, Electron Affinities, and Polarization Energies of Organic Molecular Crystals: Quantitative Estimations from a Polarizable Continuum Model (PCM)-Tuned Range-Separated Density Functional Approach. J Chem Theory Comput 2016; 12:2906-16. [DOI: 10.1021/acs.jctc.6b00225] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Haitao Sun
- Solar & Photovoltaics Engineering Research Center, Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
- State
Key Laboratory of Precision Spectroscopy, School of Physics and Materials
Science, East China Normal University (ECNU), Shanghai 200062, People’s Republic of China
| | - Sean Ryno
- Solar & Photovoltaics Engineering Research Center, Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Cheng Zhong
- Solar & Photovoltaics Engineering Research Center, Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Mahesh Kumar Ravva
- Solar & Photovoltaics Engineering Research Center, Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Zhenrong Sun
- State
Key Laboratory of Precision Spectroscopy, School of Physics and Materials
Science, East China Normal University (ECNU), Shanghai 200062, People’s Republic of China
| | | | - Jean-Luc Brédas
- Solar & Photovoltaics Engineering Research Center, Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
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12
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Floris A, Haq S, In’t Veld M, Amabilino DB, Raval R, Kantorovich L. Driving Forces for Covalent Assembly of Porphyrins by Selective C–H Bond Activation and Intermolecular Coupling on a Copper Surface. J Am Chem Soc 2016; 138:5837-47. [DOI: 10.1021/jacs.5b11594] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Andrea Floris
- Department
of Physics, King’s College London, London, Strand WC2R 2LS, United Kingdom
- School
of Mathematics and Physics, University of Lincoln, Brayford Pool, Lincoln LN6 7TS, United Kingdom
| | - Sam Haq
- Surface
Science Research Center and Department of Chemistry, University of Liverpool, Liverpool L69 3BX, United Kingdom
| | - Mendel In’t Veld
- Surface
Science Research Center and Department of Chemistry, University of Liverpool, Liverpool L69 3BX, United Kingdom
| | - David B. Amabilino
- School
of Chemistry, The University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Rasmita Raval
- Surface
Science Research Center and Department of Chemistry, University of Liverpool, Liverpool L69 3BX, United Kingdom
| | - Lev Kantorovich
- Department
of Physics, King’s College London, London, Strand WC2R 2LS, United Kingdom
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13
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Tuca E, Paci I. Fundamental aspects in surface self-assembly: theoretical implications of molecular polarity and shape. Phys Chem Chem Phys 2016; 18:6498-508. [PMID: 26864632 DOI: 10.1039/c5cp04479k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We investigate fundamental aspects of structure formation in molecular self-assembly, by examining the emergence of order upon adsorption of a series of model molecules. It is known that strongly polar diatomic molecules form three-dimensional crystals in the absence of a substrate. This tendency can be disrupted upon assembly on a solid surface, and various other types of order may arise. Depending on the relative strength of the interactions, disordered phases, two-dimensional crystals commensurate to the surface, and unmodified crystals were observed upon adsorption of simple dipoles in the present work. Introduction of steric features, in the form of a longer backbone or substituents external to the polar pair, led to even richer phase diagrams. The formation of two-dimensional phases with nematic (parallel) or antiparallel alignment was accomplished by altering the polarity of the end groups on needle-like molecules, whereas embedded charged groups made two-dimensional structure unstable for even very long molecules. These molecules preferred to align in long, often desorbed, molecular wires. The wealth of phases observed here parallel the results of experimental systematic or incidental studies of the relationships between molecular interactions and self-assembled patterns, and provide some insight into the molecular handles that self-assembly researchers can wield to guide the process towards a desired structural outcome.
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Affiliation(s)
- Emilian Tuca
- Department of Chemistry and the Centre for Advanced Materials and Related Technology, University of Victoria, Victoria, BC V8W 3V6, Canada.
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14
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Jin W, Liu Q, Dougherty DB, Cullen WG, Reutt-Robey JE, Weeks J, Robey SW. C60 chain phases on ZnPc/Ag(111) surfaces: Supramolecular organization driven by competing interactions. J Chem Phys 2015; 142:101910. [DOI: 10.1063/1.4906044] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- W. Jin
- Department of Chemistry and Biochemistry, University of Maryland at College Park, College Park, Maryland 20742, USA
| | - Q. Liu
- Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, USA
| | - D. B. Dougherty
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - W. G. Cullen
- Department of Physics, University of Maryland at College Park, College Park, Maryland 20742, USA
| | - J. E. Reutt-Robey
- Department of Chemistry and Biochemistry, University of Maryland at College Park, College Park, Maryland 20742, USA
| | - J. Weeks
- Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, USA
| | - S. W. Robey
- National Institute of Standards and Technology, Gaithersburg, Maryland 20878-8372, USA
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15
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Pivetta M, Pacchioni GE, Fernandes E, Brune H. Temperature-dependent self-assembly of NC–Ph5–CN molecules on Cu(111). J Chem Phys 2015; 142:101928. [DOI: 10.1063/1.4909518] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Marina Pivetta
- Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Giulia E. Pacchioni
- Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Edgar Fernandes
- Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Harald Brune
- Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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16
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Zhao H, Zhang S, Li S, Song X, Liu W, Liu B, Dong M. Investigation of the non-covalent interactions of molecular self-assembly by scanning tunneling microscopy using the association of aromatic structures in pyrene-4,5,9,10-tetraone and phenanthrene-9,10-dione molecules. RSC Adv 2015. [DOI: 10.1039/c5ra20316c] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The self-assembled monolayers of aromatic molecules (pyrene-4,5,9,10-tetraone and phenanthrene-9,10-dione) were investigated at the liquid/solid (1-phenyloctane/graphite) interface using scanning tunneling microscopy, respectively.
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Affiliation(s)
- Huiling Zhao
- Institute of Photo-biophysics
- School of Physics and Electronics
- Henan University
- China
- Interdisciplinary Nanoscience Center (iNANO)
| | - Shuai Zhang
- Interdisciplinary Nanoscience Center (iNANO)
- Aarhus University
- DK 8000 Aarhus C
- Denmark
| | - Shuang Li
- School of Materials Science and Engineering
- Nanjing University of Science and Technology
- China
| | - Xin Song
- Interdisciplinary Nanoscience Center (iNANO)
- Aarhus University
- DK 8000 Aarhus C
- Denmark
| | - Wei Liu
- School of Materials Science and Engineering
- Nanjing University of Science and Technology
- China
| | - Bo Liu
- Institute of Photo-biophysics
- School of Physics and Electronics
- Henan University
- China
| | - Mingdong Dong
- Interdisciplinary Nanoscience Center (iNANO)
- Aarhus University
- DK 8000 Aarhus C
- Denmark
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17
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Della Pia A, Riello M, Floris A, Stassen D, Jones TS, Bonifazi D, De Vita A, Costantini G. Anomalous coarsening driven by reversible charge transfer at metal-organic interfaces. ACS NANO 2014; 8:12356-64. [PMID: 25419580 PMCID: PMC4278690 DOI: 10.1021/nn505063w] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 11/24/2014] [Indexed: 05/20/2023]
Abstract
The unique electronic properties and functional tunability of polycyclic aromatic hydrocarbons have recently fostered high hopes for their use in flexible, green, portable, and cheap technologies. Most applications require the deposition of thin molecular films onto conductive electrodes. The growth of the first few molecular layers represents a crucial step in the device fabrication since it determines the structure of the molecular film and the energy level alignment of the metal-organic interface. Here, we explore the formation of this interface by analyzing the interplay between reversible molecule-substrate charge transfer, yielding intermolecular repulsion, and van der Waals attractions in driving the molecular assembly. Using a series of ad hoc designed molecules to balance the two effects, we combine scanning tunnelling microscopy with atomistic simulations to study the self-assembly behavior. Our systematic analysis identifies a growth mode characterized by anomalous coarsening that we anticipate to occur in a wide class of metal-organic interfaces and which should thus be considered as integral part of the self-assembly process when depositing a molecule on a conducting surface.
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Affiliation(s)
- Ada Della Pia
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, United Kingdom
| | - Massimo Riello
- Department of Physics, King’s College London, Strand, London WC2R 2LS, United Kingdom
| | - Andrea Floris
- Department of Physics, King’s College London, Strand, London WC2R 2LS, United Kingdom
| | - Daphne Stassen
- Namur Research College (NARC) and Department of Chemistry, University of Namur (UNamur), Namur, Belgium B-5000
| | - Tim S. Jones
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, United Kingdom
| | - Davide Bonifazi
- Namur Research College (NARC) and Department of Chemistry, University of Namur (UNamur), Namur, Belgium B-5000
- Department of Pharmaceutical and Chemical Sciences and INSTM UdR di Trieste, University of Trieste, Trieste, Italy I-34127
- Address correspondence to , ,
| | - Alessandro De Vita
- Department of Physics, King’s College London, Strand, London WC2R 2LS, United Kingdom
- Department of Engineering and Architecture, University of Trieste, Trieste, Italy I-34127
- Address correspondence to , ,
| | - Giovanni Costantini
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, United Kingdom
- Address correspondence to , ,
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18
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Sumpter BG, Liang L, Nicolaï A, Meunier V. Interfacial properties and design of functional energy materials. Acc Chem Res 2014; 47:3395-405. [PMID: 24963787 DOI: 10.1021/ar500180h] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
CONSPECTUS: The vital importance of energy to society continues to demand a relentless pursuit of energy responsive materials that can bridge fundamental chemical structures at the molecular level and achieve improved functionality and performance. This demand can potentially be realized by harnessing the power of self-assembly, a spontaneous process where molecules or much larger entities form ordered aggregates as a consequence of predominately noncovalent (weak) interactions. Self-assembly is the key to bottom-up design of molecular devices, because the nearly atomic-level control is very difficult to realize in a top-down, for example, lithographic, approach. However, while function in simple systems such as single crystals can often be evaluated a priori, predicting the function of the great variety of self-assembled molecular architectures is complicated by the lack of understanding and control over nanoscale interactions, mesoscale architectures, and macroscale order. To establish a foundation toward delivering practical solutions, it is critical to develop an understanding of the chemical and physical mechanisms responsible for the self-assembly of molecular and hybrid materials on various support substrates. Typical molecular self-assembly involves noncovalent intermolecular and substrate-molecule interactions. These interactions remain poorly understood, due to the combination of many-body interactions compounded by local or collective influences from the substrate atomic lattice and electronic structure. Progress toward unraveling the underlying physicochemical processes that control the structure and macroscopic physical, chemical, mechanical, electrical, and transport properties of materials increasingly requires tight integration of theory, modeling, and simulation with precision synthesis, advanced experimental characterization, and device measurements. Theory, modeling, and simulation can accelerate the process of materials understanding and design by providing atomic level understanding of the underlying physicochemical phenomena (illuminating connections between experiments). It can also provide the ability to explore new materials and conditions before they are realized in the laboratory. With tight integration and feedback with experiment, it becomes feasible to identify promising materials or processes for targeted energy applications. In this Account, we highlight recent advances and success in using an integrated approach based on electronic structure simulations and scanning probe microscopy techniques to study and design functional materials formed from the self-assembly of molecules into supramolecular or polymeric architectures on substrates.
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Affiliation(s)
- Bobby G. Sumpter
- Center for Nanophase Materials Sciences and Computer Science & Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Liangbo Liang
- Department
of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Adrien Nicolaï
- Department
of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Vincent Meunier
- Department
of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
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19
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Cirera B, Zhang YQ, Björk J, Klyatskaya S, Chen Z, Ruben M, Barth JV, Klappenberger F. Synthesis of extended graphdiyne wires by vicinal surface templating. NANO LETTERS 2014; 14:1891-7. [PMID: 24564910 DOI: 10.1021/nl4046747] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Surface-assisted covalent synthesis currently evolves into an important approach for the fabrication of functional nanostructures at interfaces. Here, we employ scanning tunneling microscopy to investigate the homocoupling reaction of linear, terminal alkyne-functionalized polyphenylene building-blocks on noble metal surfaces under ultrahigh vacuum. On the flat Ag(111) surface, thermal activation triggers a variety of side-reactions resulting in irregularly branched polymeric networks. Upon alignment along the step-edges of the Ag(877) vicinal surface drastically improves the chemoselectivity of the linking process permitting the controlled synthesis of extended-graphdiyne wires with lengths reaching 30 nm. The ideal hydrocarbon scaffold is characterized by density functional theory as a 1D, direct band gap semiconductor material with both HOMO and LUMO-derived bands promisingly isolated within the electronic structure. The templating approach should be applicable to related organic precursors and different reaction schemes thus bears general promise for the engineering of novel low-dimensional carbon-based materials.
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Affiliation(s)
- Borja Cirera
- Physik Department E20, Technische Universität München , James-Franck-Straße, 85748 Garching, Germany
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20
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Golze D, Iannuzzi M, Nguyen MT, Passerone D, Hutter J. Simulation of Adsorption Processes at Metallic Interfaces: An Image Charge Augmented QM/MM Approach. J Chem Theory Comput 2013; 9:5086-97. [DOI: 10.1021/ct400698y] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dorothea Golze
- Institute of Physical Chemistry, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Marcella Iannuzzi
- Institute of Physical Chemistry, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Manh-Thuong Nguyen
- The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, I-34151 Trieste, Italy
| | - Daniele Passerone
- Empa, Swiss Federal Laboratories for Materials Science and Technology, nanotech@surfaces Laboratory, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
| | - Jürg Hutter
- Institute of Physical Chemistry, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
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21
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Floris A, Comisso A, De Vita A. Fine-tuning the electrostatic properties of an alkali-linked organic adlayer on a metal substrate. ACS NANO 2013; 7:8059-65. [PMID: 23968290 DOI: 10.1021/nn403274s] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The performance of modern organic electronic devices is often determined by the electronic level alignment at a metal-organic interface. This property can be controlled by introducing an interfacial electrostatic dipole via the insertion of a stable interlayer between the metallic and the organic phases. Here, we use density functional theory to investigate the electrostatic properties of an assembled structure formed by alkali metals coadsorbed with 7,7,8,8-tetracyanoquinodimethane (TCNQ) molecules on a Ag(100) substrate. We find that the interfacial dipole buildup is regulated by the interplay of adsorption energetics, steric constraints and charge transfer effects, so that choosing chemical substitutions within TCNQ and different alkali metals provides a rich playground to control the systems' electrostatics and in particular fine-tune its work-function shift.
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Affiliation(s)
- Andrea Floris
- Department of Physics, King's College London , London, Strand WC2R 2LS, United Kingdom
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22
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Bischoff F, Seufert K, Auwärter W, Joshi S, Vijayaraghavan S, Écija D, Diller K, Papageorgiou AC, Fischer S, Allegretti F, Duncan DA, Klappenberger F, Blobner F, Han R, Barth JV. How surface bonding and repulsive interactions cause phase transformations: ordering of a prototype macrocyclic compound on Ag(111). ACS NANO 2013; 7:3139-3149. [PMID: 23521075 DOI: 10.1021/nn305487c] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We investigated the surface bonding and ordering of free-base porphine (2H-P), the parent compound of all porphyrins, on a smooth noble metal support. Our multitechnique investigation reveals a surprisingly rich and complex behavior, including intramolecular proton switching, repulsive intermolecular interactions, and density-driven phase transformations. For small concentrations, molecular-level observations using low-temperature scanning tunneling microscopy clearly show the operation of repulsive interactions between 2H-P molecules in direct contact with the employed Ag(111) surface, preventing the formation of islands. An increase of the molecular coverage results in a continuous decrease of the average intermolecular distance, correlated with multiple phase transformations: the system evolves from an isotropic, gas-like configuration via a fluid-like phase to a crystalline structure, which finally gives way to a disordered layer. Herein, considerable site-specific molecule-substrate interactions, favoring an exclusive adsorption on bridge positions of the Ag(111) lattice, play an important role. Accordingly, the 2D assembly of 2H-P/Ag(111) layers is dictated by the balance between adsorption energy maximization while retaining a single adsorption site counteracted by the repulsive molecule-molecule interactions. The long-range repulsion is associated with a charge redistribution at the 2H-P/Ag(111) interface comprising a partial filling of the lowest unoccupied molecular orbital, resulting in long-range electrostatic interactions between the adsorbates. Indeed, 2H-P molecules in the second layer that are electronically only weakly coupled to the Ag substrate show no repulsive behavior, but form dense-packed islands.
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Affiliation(s)
- Felix Bischoff
- Physik Department E20, Technische Universität München, James Franck Straße 1, D-85748 Garching, Germany
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23
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Zhang C, Du C, Yan H, Yuan S, Chi L. Influence of self-assembled monolayers on the growth and crystallization of rubrene films: a molecular dynamics study. RSC Adv 2013. [DOI: 10.1039/c3ra41085d] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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24
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25
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Müllegger S, Rashidi M, Fattinger M, Koch R. Interactions and Self-Assembly of Stable Hydrocarbon Radicals on a Metal Support. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2012; 116:22587-22594. [PMID: 23378866 PMCID: PMC3557927 DOI: 10.1021/jp3068409] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 09/03/2012] [Indexed: 06/01/2023]
Abstract
Stable hydrocarbon radicals are able to withstand ambient conditions. Their combination with a supporting surface is a promising route toward novel functionalities or carbon-based magnetic systems. This will remain elusive until the interplay of radical-radical interactions and interface effects is fundamentally explored. We employ the tip of a low-temperature scanning tunneling microscope as a local probe in combination with density functional theory calculations to investigate with atomic precision the electronic and geometric effects of a weakly interacting metal support on an archetypal hydrocarbon radical model system, i.e., the exceptionally stable spin-1/2 radical α,γ-bisdiphenylene-β-phenylallyl (BDPA). Our study demonstrates the self-assembly of stable and regular one- and two-dimensional radical clusters on the Au(111) surface. Different types of geometric configurations are found to result from the interplay between the highly anisotropic radical-radical interactions and interface effects. We investigate the interaction mechanisms underlying the self-assembly processes and utilize the different configurations as a geometric design parameter to demonstrate energy shifts of up to 0.6 eV of the radicals' frontier molecular orbitals responsible for their electronic, magnetic, and chemical properties.
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Affiliation(s)
- Stefan Müllegger
- Institute
of Semiconductor and Solid State Physics, Johannes Kepler
University Linz, 4040 Linz, Austria
| | - Mohammad Rashidi
- Institute
of Semiconductor and Solid State Physics, Johannes Kepler
University Linz, 4040 Linz, Austria
| | - Michael Fattinger
- Institute
of Semiconductor and Solid State Physics, Johannes Kepler
University Linz, 4040 Linz, Austria
| | - Reinhold Koch
- Institute
of Semiconductor and Solid State Physics, Johannes Kepler
University Linz, 4040 Linz, Austria
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26
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Iacovita C, Fesser P, Vijayaraghavan S, Enache M, Stöhr M, Diederich F, Jung TA. Controlling the dimensionality and structure of supramolecular porphyrin assemblies by their functional substituents: dimers, chains, and close-packed 2D assemblies. Chemistry 2012; 18:14610-3. [PMID: 23065935 DOI: 10.1002/chem.201201037] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Revised: 08/29/2012] [Indexed: 11/05/2022]
Abstract
Repulsive interactions: a staging of supramolecular aggregation from (0D) clusters to (1D) chains and (2D) assemblies as a function of molecular coverage of dipolar porphyrins adsorbed on the Ag(111) surface is described. It displays a complex interplay of both attractive and repulsive molecule-molecule interactions, the emergence of chirality, and the registry of the substrate.
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27
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Abdurakhmanova N, Floris A, Tseng TC, Comisso A, Stepanow S, De Vita A, Kern K. Stereoselectivity and electrostatics in charge-transfer Mn- and Cs-TCNQ₄ networks on Ag(100). Nat Commun 2012; 3:940. [PMID: 22760639 DOI: 10.1038/ncomms1942] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 05/29/2012] [Indexed: 11/09/2022] Open
Abstract
Controlling supramolecular self-assembly is a fundamental step towards molecular nanofabrication, which involves a formidable reverse engineering problem. It is known that a variety of structures are efficiently obtained by assembling appropriate organic molecules and transition metal atoms on well-defined substrates. Here we show that alkali atoms bring in new functionalities compared with transition metal atoms because of the interplay of local chemical bonding and long-range forces. Using atomic-resolution microscopy and theoretical modelling, we investigate the assembly of alkali (Cs) and transition metals (Mn) co-adsorbed with 7,7,8,8-tetracyanoquinodimethane (TCNQ) molecules, forming chiral superstructures on Ag(100). Whereas Mn-TCNQ(4) domains are achiral, Cs-TCNQ(4) forms chiral islands. The specific behaviour is traced back to the different nature of the Cs- and Mn-TCNQ bonding, opening a novel route for the chiral design of supramolecular architectures. Moreover, alkali atoms provide a means to modify the adlayer electrostatic properties, which is important for the design of metal-organic interfaces.
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Affiliation(s)
- Nasiba Abdurakhmanova
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
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28
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Duhm S, Xin Q, Hosoumi S, Fukagawa H, Sato K, Ueno N, Kera S. Charge reorganization energy and small polaron binding energy of rubrene thin films by ultraviolet photoelectron spectroscopy. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2012; 24:901-905. [PMID: 22403829 DOI: 10.1002/adma.201103262] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The hole–phonon coupling of a rubrene monolayer on graphite is measured by means of angle resolved ultraviolet photoelectron spectroscopy. Thus, the charge reorganization energy λ and the small polaron binding energy is determined, which allows insight into the nature of charge transport in condensed rubrene.
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Affiliation(s)
- Steffen Duhm
- Graduate School of Advanced Integration Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, Japan.
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29
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Walch H, Dienstmaier J, Eder G, Gutzler R, Schlögl S, Sirtl T, Das K, Schmittel M, Lackinger M. Extended two-dimensional metal-organic frameworks based on thiolate-copper coordination bonds. J Am Chem Soc 2011; 133:7909-15. [PMID: 21534586 DOI: 10.1021/ja200661s] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Self-assembly and surface-mediated reactions of 1,3,5-tris(4-mercaptophenyl)benzene--a three-fold symmetric aromatic trithiol--are studied on Cu(111) by means of scanning tunneling microscopy (STM) under ultrahigh-vacuum (UHV) conditions. In order to reveal the nature of intermolecular bonds and to understand the specific role of the substrate for their formation, these studies were extended to Ag(111). Room-temperature deposition onto either substrate yields densely packed trigonal structures with similar appearance and lattice parameters. Yet, thermal annealing reveals distinct differences between both substrates: on Cu(111) moderate annealing temperatures (~150 °C) already drive the emergence of two different porous networks, whereas on Ag(111) higher annealing temperatures (up to ~300 °C) were required to induce structural changes. In the latter case only disordered structures with characteristic dimers were observed. These differences are rationalized by the contribution of the adatom gas on Cu(111) to the formation of metal-coordination bonds. Density functional theory (DFT) methods were applied to identify intermolecular bonds in both cases by means of their bond distances and geometries.
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Affiliation(s)
- Hermann Walch
- Department for Earth and Environmental Sciences and Center for NanoScience, Ludwig-Maximilians-Universität, Theresienstrasse 41, 80333 München, Germany
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