1
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Seibel J, Anggara K, Delbianco M, Rauschenbach S. Scanning Probe Microscopy Characterization of Biomolecules enabled by Mass-Selective, Soft-landing Electrospray Ion Beam Deposition. Chemphyschem 2024:e202400419. [PMID: 38945838 DOI: 10.1002/cphc.202400419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 06/26/2024] [Accepted: 06/27/2024] [Indexed: 07/02/2024]
Abstract
Scanning probe microscopy (SPM), in particular at low temperature (LT) under ultra-high vacuum (UHV) conditions, offers the possibility of real-space imaging with resolution reaching the atomic level. However, its potential for the analysis of complex biological molecules has been hampered by requirements imposed by sample preparation. Transferring molecules onto surfaces in UHV is typically accomplished by thermal sublimation in vacuum. This approach however is limited by the thermal stability of the molecules, i. e. not possible for biological molecules with low vapour pressure. Bypassing this limitation, electrospray ionisation offers an alternative method to transfer molecules from solution to the gas-phase as intact molecular ions. In soft-landing electrospray ion beam deposition (ESIBD), these molecular ions are subsequently mass-selected and gently landed on surfaces which permits large and thermally fragile molecules to be analyzed by LT-UHV SPM. In this concept, we discuss how ESIBD+SPM prepares samples of complex biological molecules at a surface, offering controls of the molecular structural integrity, three-dimensional shape, and purity. These achievements unlock the analytical potential of SPM which is showcased by imaging proteins, peptides, DNA, glycans, and conjugates of these molecules, revealing details of their connectivity, conformation, and interaction that could not be accessed by any other technique.
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Affiliation(s)
- Johannes Seibel
- Institute of Physical Chemistry, Karlsruhe Institute of Technology, Fritz-Haber Weg 2, D-76131, Karlsruhe, Germany
| | - Kelvin Anggara
- Nanoscale Science Department, Max Planck Institute for Solid State Research, Heisenbergstr. 1, D-70569, Stuttgart, Germany
| | - Martina Delbianco
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, D-14476, Potsdam, Germany
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2
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Bauer A, Birk T, Paschke F, Fuhrberg A, Diegel J, Becherer AK, Vogelsang L, Maier M, Schosser WM, Pauly F, Zilberberg O, Winter RF, Fonin M. Fully Reprogrammable 2D Array of Multistate Molecular Switching Units. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2401662. [PMID: 38749066 DOI: 10.1002/adma.202401662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 04/23/2024] [Indexed: 07/21/2024]
Abstract
Integration of molecular switching units into complex electronic circuits is considered to be the next step toward the realization of novel logic and memory devices. This paper reports on an ordered 2D network of neighboring ternary switching units represented by triazatruxene (TAT) molecules organized in a honeycomb lattice on a Ag(111) surface. Using low-temperature scanning tunneling microscopy, the bonding configurations of individual TAT molecules can be controlled, realizing up to 12 distinct states per molecule. The switching between those states shows a strong bias dependence ranging from tens of millivolts to volts. The low-bias switching behavior is explored in active units consisting of two and more interacting TAT molecules that are purposefully defined (programmed) by high-bias switching within the honeycomb lattice. Within such a unit the low-bias switching can be triggered and accessed by single-point measurements on a single TAT molecule, demonstrating up to 9 and 19 distinguishable states in a dyad and a tetrad of coupled molecules, respectively. High experimental control over the desired state, owing to bias-dependent hierarchical switching and pronounced switching directionality, as well as full reversibility, make this system particularly appealing, paving the way to design complex molecule-based memory systems.
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Affiliation(s)
- Anja Bauer
- Fachbereich Physik, Universität Konstanz, 78457, Konstanz, Germany
| | - Tobias Birk
- Fachbereich Physik, Universität Konstanz, 78457, Konstanz, Germany
| | - Fabian Paschke
- Fachbereich Physik, Universität Konstanz, 78457, Konstanz, Germany
| | - Andreas Fuhrberg
- Fachbereich Physik, Universität Konstanz, 78457, Konstanz, Germany
| | - Josefine Diegel
- Fachbereich Physik, Universität Konstanz, 78457, Konstanz, Germany
| | | | - Lars Vogelsang
- Fachbereich Chemie, Universität Konstanz, 78457, Konstanz, Germany
| | - Markus Maier
- Fachbereich Chemie, Universität Konstanz, 78457, Konstanz, Germany
| | - Werner M Schosser
- Institute of Physics and Centre for Advanced Analytics and Predictive Sciences, University of Augsburg, 86159, Augsburg, Germany
| | - Fabian Pauly
- Institute of Physics and Centre for Advanced Analytics and Predictive Sciences, University of Augsburg, 86159, Augsburg, Germany
| | - Oded Zilberberg
- Fachbereich Physik, Universität Konstanz, 78457, Konstanz, Germany
| | - Rainer F Winter
- Fachbereich Chemie, Universität Konstanz, 78457, Konstanz, Germany
| | - Mikhail Fonin
- Fachbereich Physik, Universität Konstanz, 78457, Konstanz, Germany
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3
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Tang C, Stuyver T, Lu T, Liu J, Ye Y, Gao T, Lin L, Zheng J, Liu W, Shi J, Shaik S, Xia H, Hong W. Voltage-driven control of single-molecule keto-enol equilibrium in a two-terminal junction system. Nat Commun 2023; 14:3657. [PMID: 37339947 DOI: 10.1038/s41467-023-39198-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 05/30/2023] [Indexed: 06/22/2023] Open
Abstract
Keto-enol tautomerism, describing an equilibrium involving two tautomers with distinctive structures, provides a promising platform for modulating nanoscale charge transport. However, such equilibria are generally dominated by the keto form, while a high isomerization barrier limits the transformation to the enol form, suggesting a considerable challenge to control the tautomerism. Here, we achieve single-molecule control of a keto-enol equilibrium at room temperature by using a strategy that combines redox control and electric field modulation. Based on the control of charge injection in the single-molecule junction, we could access charged potential energy surfaces with opposite thermodynamic driving forces, i.e., exhibiting a preference for the conducting enol form, while the isomerization barrier is also significantly reduced. Thus, we could selectively obtain desired and stable tautomers, which leads to significant modulation of the single-molecule conductance. This work highlights the concept of single-molecule control of chemical reactions on more than one potential energy surface.
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Affiliation(s)
- Chun Tang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
- Shenzhen Grubbs Institute, Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, P. R. China
| | - Thijs Stuyver
- Institute of Chemistry, Edmond J. Safra Campus at Givat Ram, The Hebrew University, Jerusalem, 91904, Israel
- Ecole Nationale Supérieure de Chimie de Paris, Université PSL, CNRS, Institute of Chemistry for Life and Health Sciences, 75 005, Paris, France
| | - Taige Lu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Junyang Liu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Yiling Ye
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Tengyang Gao
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Luchun Lin
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Jueting Zheng
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Wenqing Liu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Jia Shi
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Sason Shaik
- Institute of Chemistry, Edmond J. Safra Campus at Givat Ram, The Hebrew University, Jerusalem, 91904, Israel.
| | - Haiping Xia
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China.
- Shenzhen Grubbs Institute, Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, P. R. China.
| | - Wenjing Hong
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China.
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4
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Christ A, Bode M, Leisegang M. Real-space resolved surface reactions: deprotonation and metalation of phthalocyanine. Phys Chem Chem Phys 2023; 25:7681-7687. [PMID: 36857662 DOI: 10.1039/d2cp05716f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Upon deposition on a surface, molecules can undergo a plethora of changes, such as reactions with adsorbates and surface atoms and catalytic decomposition. Since different reaction pathways may coexist, spatially averaging techniques can be insufficient for the characterization and distinction of all on-surface products. Here, we present a study of single phthalocyanine molecules on a Cu(111) surface which was performed using high-resolution low-temperature STM. Upon deposition of metal-free H2Pc, we can identify three distinct molecular species. A thorough investigation reveals that temperature-driven on-surface reactions partially convert H2Pc into H0Pc and CuPc. The individual species are differentiated by their topographic appearance and can unambiguously be identified by their STM-induced rotational behavior. While H2Pc shows a switching between two orientations at low energies, a third orientation can be observed above E > 800 meV, which is induced by tautomerization. Around the Fermi level, the rotational behavior is asymmetric, owing to the excitation of vibrational modes in unoccupied states whereas resonant tunneling occurs in occupied states. A two-step deprotonation of H2Pc confirms that the second species is H0Pc. By comparison with CuPc evaporated on Cu(111), we unambiguously reveal that the third species is indeed CuPc, which exhibits an exceptionally low threshold for rotational switching accompanied by an asymmetric behavior around the Fermi level. Varying the post-annealing temperature, we found a sharp threshold for the H2Pc → CuPc on-surface metalation at around 100 °C. In contrast, the competing process of thermal decomposition from H2Pc to H0Pc only increases weakly.
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Affiliation(s)
- Andreas Christ
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Matthias Bode
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany. .,Wilhelm Conrad Röntgen-Center for Complex Material Systems (RCCM), Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Markus Leisegang
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
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5
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Rascon EC, Riss A, Matěj A, Wiengarten A, Mutombo P, Soler D, Jelinek P, Auwärter W. On-Surface Synthesis of Square-Type Porphyrin Tetramers with Central Antiaromatic Cyclooctatetraene Moiety. J Am Chem Soc 2023; 145:967-977. [PMID: 36580274 DOI: 10.1021/jacs.2c10088] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The synthesis of two-dimensionally extended polycyclic heteroatomic molecules keeps attracting considerable attention. In particular, frameworks bearing planar cyclooctatetraenes (COT) moieties can display intriguing properties, including antiaromaticity. Here, we present an on-surface chemistry route to square-type porphyrin tetramers with a central COT ring, coexisting with other oligomers. This approach employing temperature-induced dehydrogenative porphyrin homocoupling in an ultrahigh vacuum environment provides access to surface-supported, unsubstituted porphyrin tetramers that are not easily achievable by conventional synthesis means. Specifically, monomeric free-base (2H-P) and Zn-metalated (Zn-P) porphines (P) were employed to form square-type free-base and Zn-functionalized tetramers on Ag(100). An atomic-level characterization by bond-resolved atomic force microscopy and scanning tunneling microscopy and spectroscopy is provided, identifying the molecular structures. Complemented by density functional theory modeling, the electronic structure is elucidated, indeed revealing antiaromaticity induced by the COT moiety. The present study thus gives access, and insights, to a porphyrin oligomer, representing both a model system for directly fused porphyrins and a potential building block for conjugated, extended two-dimensional porphyrin sheets.
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Affiliation(s)
- Eduardo Corral Rascon
- Physics Department E20, Technical University of Munich, James-Franck Str. 1, 85748 Garching, Germany
| | - Alexander Riss
- Physics Department E20, Technical University of Munich, James-Franck Str. 1, 85748 Garching, Germany
| | - Adam Matěj
- Institute of Physics, Czech Academy of Sciences, 162 00 Prague, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacky University in Olomouc, 779 00 Olomouc, Czech Republic.,Department of Physical Chemistry, Faculty of Science, Palacky University in Olomouc, 779 00 Olomouc, Czech Republic
| | - Alissa Wiengarten
- Physics Department E20, Technical University of Munich, James-Franck Str. 1, 85748 Garching, Germany
| | - Pingo Mutombo
- Institute of Physics, Czech Academy of Sciences, 162 00 Prague, Czech Republic
| | - Diego Soler
- Institute of Physics, Czech Academy of Sciences, 162 00 Prague, Czech Republic
| | - Pavel Jelinek
- Institute of Physics, Czech Academy of Sciences, 162 00 Prague, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacky University in Olomouc, 779 00 Olomouc, Czech Republic
| | - Willi Auwärter
- Physics Department E20, Technical University of Munich, James-Franck Str. 1, 85748 Garching, Germany
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6
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Rothe K, Néel N, Bocquet ML, Kröger J. Extraction of Chemical Reactivity and Structural Relaxations of an Organic Dye from the Short-Range Interaction with a Molecular Probe. J Phys Chem Lett 2022; 13:8660-8665. [PMID: 36084075 DOI: 10.1021/acs.jpclett.2c02140] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
A CO-functionalized atomic force microscope tip is used to locally probe local chemical reactivity and subtle structural relaxations of a single phthalocyanine molecule at different stages of pyrrolic-H abstraction. Spatially resolved vertical force spectroscopy unveils a variation of the maximum short-range attraction between CO and intramolecular sites, which is interpreted as a measure for the local chemical reactivity. In addition, the vertical position of the point of maximum attraction is observed to vary across the molecules. These changes follow the calculated adsorption heights of the probed molecular atoms.
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Affiliation(s)
- Karl Rothe
- Institut für Physik, Technische Universität Ilmenau, D-98693 Ilmenau, Germany
| | - Nicolas Néel
- Institut für Physik, Technische Universität Ilmenau, D-98693 Ilmenau, Germany
| | - Marie-Laure Bocquet
- Laboratoire de Physique de l'École Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris-Diderot, Sorbonne Paris Cité, F-75005 Paris, France
| | - Jörg Kröger
- Institut für Physik, Technische Universität Ilmenau, D-98693 Ilmenau, Germany
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7
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Li P, Zhou L, Zhao C, Ju H, Gao Q, Si W, Cheng L, Hao J, Li M, Chen Y, Jia C, Guo X. Single-molecule nano-optoelectronics: insights from physics. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2022; 85:086401. [PMID: 35623319 DOI: 10.1088/1361-6633/ac7401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 05/27/2022] [Indexed: 06/15/2023]
Abstract
Single-molecule optoelectronic devices promise a potential solution for miniaturization and functionalization of silicon-based microelectronic circuits in the future. For decades of its fast development, this field has made significant progress in the synthesis of optoelectronic materials, the fabrication of single-molecule devices and the realization of optoelectronic functions. On the other hand, single-molecule optoelectronic devices offer a reliable platform to investigate the intrinsic physical phenomena and regulation rules of matters at the single-molecule level. To further realize and regulate the optoelectronic functions toward practical applications, it is necessary to clarify the intrinsic physical mechanisms of single-molecule optoelectronic nanodevices. Here, we provide a timely review to survey the physical phenomena and laws involved in single-molecule optoelectronic materials and devices, including charge effects, spin effects, exciton effects, vibronic effects, structural and orbital effects. In particular, we will systematically summarize the basics of molecular optoelectronic materials, and the physical effects and manipulations of single-molecule optoelectronic nanodevices. In addition, fundamentals of single-molecule electronics, which are basic of single-molecule optoelectronics, can also be found in this review. At last, we tend to focus the discussion on the opportunities and challenges arising in the field of single-molecule optoelectronics, and propose further potential breakthroughs.
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Affiliation(s)
- Peihui Li
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Li Zhou
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Cong Zhao
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Hongyu Ju
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
- School of Pharmaceutical Science and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, People's Republic of China
| | - Qinghua Gao
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Wei Si
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Li Cheng
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Jie Hao
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Mengmeng Li
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Yijian Chen
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Chuancheng Jia
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, People's Republic of China
| | - Xuefeng Guo
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, People's Republic of China
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8
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The role of structural symmetry on proton tautomerization: A DFTB/Meta-Dynamics computational study. Chem Phys 2021. [DOI: 10.1016/j.chemphys.2021.111222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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9
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Leisegang M, Christ A, Haldar S, Heinze S, Bode M. Molecular Chains: Arranging and Programming Logic Gates. NANO LETTERS 2021; 21:550-555. [PMID: 33290080 DOI: 10.1021/acs.nanolett.0c03984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
One particularly fascinating vision for charge-operated devices is the controlled assembly of structures from single surface-deposited molecules. Here, we report on the assembly of linear clusters that consist of phthalocyanine (H2Pc) molecules on a Ag(111) surface. The molecules are imaged as well as manipulated with a low-temperature scanning tunneling microscope (STM). Upon deprotonation of every second H2Pc, the resulting HPc molecule exhibits an isomeric bistability which can be used as inputs in logic gates. Combining our STM measurements with density functional theory calculations we show that the HPc isomers exhibit a repulsive electrostatic interaction with adjacent H2Pc molecules which, due to the asymmetric charge distribution on HPc, results in a counterclockwise or clockwise molecule tilt of the latter, thereby defining the logic 0 and 1 of the output. It is shown that information can be relayed along molecule chains over distances equivalent to at least nine molecules.
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Affiliation(s)
- Markus Leisegang
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Andreas Christ
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Soumyajyoti Haldar
- Institute of Theoretical Physics and Astrophysics, University of Kiel, Leibnizstrasse 15, 24098 Kiel, Germany
| | - Stefan Heinze
- Institute of Theoretical Physics and Astrophysics, University of Kiel, Leibnizstrasse 15, 24098 Kiel, Germany
| | - Matthias Bode
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Wilhelm Conrad Röntgen-Center for Complex Material Systems (RCCM), Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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10
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Homberg J, Weismann A, Berndt R, Gruber M. Inducing and Controlling Molecular Magnetism through Supramolecular Manipulation. ACS NANO 2020; 14:17387-17395. [PMID: 33225694 DOI: 10.1021/acsnano.0c07574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Diamagnetic H2 phthalocyanine molecules are probed on superconducting Pb(100) using a low-temperature scanning tunneling micoscope (STM). In supramolecular arrays made with the STM, the molecules acquire a spin as detected via the emergence of Yu-Shiba-Rusinov resonances. The spin moments vary among the molecules and are determined by the electrostatic field that results from polar bonds in the surrounding Pc molecules. The moments are further finely tuned by repositioning the hydrogen atoms of the inner macrocycle of the surrounding molecules.
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Affiliation(s)
- Jan Homberg
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098 Kiel, Germany
| | - Alexander Weismann
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098 Kiel, Germany
| | - Richard Berndt
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098 Kiel, Germany
| | - Manuel Gruber
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität, 24098 Kiel, Germany
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11
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Rai V, Gerhard L, Sun Q, Holzer C, Repän T, Krstić M, Yang L, Wegener M, Rockstuhl C, Wulfhekel W. Boosting Light Emission from Single Hydrogen Phthalocyanine Molecules by Charging. NANO LETTERS 2020; 20:7600-7605. [PMID: 32960069 DOI: 10.1021/acs.nanolett.0c03121] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Interest in electroluminescence of single molecules is stimulated by the prospect of possible applications in novel light emitting devices. Recent studies provide valuable insights into the mechanisms leading to single molecule electroluminescence. Concrete information on how to boost the intensity of the emitted light, however, is rare. By combining scanning tunnelling microscopy (STM) and quantum chemical calculations, we show that the light emission efficiencies of an individual hydrogen-phthalocyanine molecule can be increased by a factor of ≈19 upon charging. This boost in intensity can be explained by the development of a vertical dipole moment normal to the substrate facilitating out-coupling of the local excitation to the far field. As this effect is not related to the specific nature of hydrogen-phthalocyanine, it opens up a general way to increase light emission from molecular junctions.
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Affiliation(s)
- Vibhuti Rai
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany
| | - Lukas Gerhard
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany
| | - Qing Sun
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany
| | - Christof Holzer
- Institute of Theoretical Solid State Physics, Karlsruhe Institute of Technology (KIT), D-76131 Karlsruhe, Germany
| | - Taavi Repän
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany
| | - Marjan Krstić
- Institute of Theoretical Solid State Physics, Karlsruhe Institute of Technology (KIT), D-76131 Karlsruhe, Germany
| | - Liang Yang
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), D-76131 Karlsruhe, Germany
| | - Martin Wegener
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), D-76131 Karlsruhe, Germany
| | - Carsten Rockstuhl
- Institute of Theoretical Solid State Physics, Karlsruhe Institute of Technology (KIT), D-76131 Karlsruhe, Germany
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany
| | - Wulf Wulfhekel
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany
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12
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Bauer A, Maier M, Schosser WM, Diegel J, Paschke F, Dedkov Y, Pauly F, Winter RF, Fonin M. Tip-Induced Inversion of the Chirality of a Molecule's Adsorption Potential Probed by the Switching Directionality. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1907390. [PMID: 32064673 DOI: 10.1002/adma.201907390] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 12/27/2019] [Indexed: 06/10/2023]
Abstract
The switching behavior of surface-supported molecular units excited by current, light, or mechanical forces is determined by the shape of the adsorption potential. The ability to tailor the energy landscape in which a molecule resides at a surface gives the possibility of imposing a desired response, which is of paramount importance for the realization of molecular electronic units. Here, by means of scanning tunneling microscopy, a triazatruxene (TAT) molecule on Ag(111) is studied, which shows a switching behavior characterized by transitions of the molecule between three states, and which is attributed to three energetically degenerate bonding configurations. Upon tunneling current injection, the system can be excited and continuously driven, showing a switching directionality close to 100%. Two surface enantiomers of TAT show opposite switching directions pointing at the chirality of the energy landscape of the adsorption potential as a key ingredient for directional switching. Further, it is shown that by tuning the tunneling parameters, the symmetry of the adsorption potential can be controllably adjusted, leading to a suppression of the directionality or an inversion of the switching direction. The findings represent a molecule-surface model system exhibiting unprecedented control of the shape of its adsorption potential.
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Affiliation(s)
- Anja Bauer
- Fachbereich Physik, Universität Konstanz, 78457, Konstanz, Germany
| | - Markus Maier
- Fachbereich Chemie, Universität Konstanz, 78457, Konstanz, Germany
| | - Werner M Schosser
- Fachbereich Physik, Universität Konstanz, 78457, Konstanz, Germany
- Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, 904-0495, Japan
| | - Josefine Diegel
- Fachbereich Physik, Universität Konstanz, 78457, Konstanz, Germany
| | - Fabian Paschke
- Fachbereich Physik, Universität Konstanz, 78457, Konstanz, Germany
| | - Yuriy Dedkov
- Department of Physics, Shanghai University, 99 Shangda Road, 200444, Shanghai, China
| | - Fabian Pauly
- Fachbereich Physik, Universität Konstanz, 78457, Konstanz, Germany
- Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, 904-0495, Japan
| | - Rainer F Winter
- Fachbereich Chemie, Universität Konstanz, 78457, Konstanz, Germany
| | - Mikhail Fonin
- Fachbereich Physik, Universität Konstanz, 78457, Konstanz, Germany
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13
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Harsh R, Joucken F, Chacon C, Repain V, Girard Y, Bellec A, Rousset S, Sporken R, Smogunov A, Dappe YJ, Lagoute J. Controlling Hydrogen-Transfer Rate in Molecules on Graphene by Tunable Molecular Orbital Levels. J Phys Chem Lett 2019; 10:6897-6903. [PMID: 31638814 DOI: 10.1021/acs.jpclett.9b02902] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Molecular switches are building blocks of potential interest to store binary information, especially when they can be organized in periodic lattices. Among the variety of possible systems, switches based on hydrogen transfer are of special importance because they allow the switching operation to occur without severe conformational change that may interfere with neighboring molecular units. We have studied the excitation process of hydrogen transfer inside porphyrin molecules assembled on a graphene surface, using a low-temperature scanning tunneling microscope. We show that this hydrogen transfer is induced by an electronic resonant tunneling process through the molecular orbitals. Using nitrogen doping of graphene, we tune the rate of hydrogen transfer by shifting the molecular orbital energies owing to the charge transfer at nitrogen dopant sites in the graphene lattice. The control of the switching process allows the storage of information inside a molecular lattice, which is demonstrated by writing an artificial pattern inside a molecular island.
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Affiliation(s)
- Rishav Harsh
- Université de Paris , Laboratoire Matériaux et Phénomènes Quantiques, CNRS , F-75013 Paris , France
| | - Frédéric Joucken
- Research Center in Physics of Matter and Radiation (PMR) , Université de Namur , 61 Rue de Bruxelles , 5000 Namur , Belgium
| | - Cyril Chacon
- Université de Paris , Laboratoire Matériaux et Phénomènes Quantiques, CNRS , F-75013 Paris , France
| | - Vincent Repain
- Université de Paris , Laboratoire Matériaux et Phénomènes Quantiques, CNRS , F-75013 Paris , France
| | - Yann Girard
- Université de Paris , Laboratoire Matériaux et Phénomènes Quantiques, CNRS , F-75013 Paris , France
| | - Amandine Bellec
- Université de Paris , Laboratoire Matériaux et Phénomènes Quantiques, CNRS , F-75013 Paris , France
| | - Sylvie Rousset
- Université de Paris , Laboratoire Matériaux et Phénomènes Quantiques, CNRS , F-75013 Paris , France
| | - Robert Sporken
- Research Center in Physics of Matter and Radiation (PMR) , Université de Namur , 61 Rue de Bruxelles , 5000 Namur , Belgium
| | - Alexander Smogunov
- SPEC, CEA, CNRS , Université Paris-Saclay , CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Yannick J Dappe
- SPEC, CEA, CNRS , Université Paris-Saclay , CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Jérôme Lagoute
- Université de Paris , Laboratoire Matériaux et Phénomènes Quantiques, CNRS , F-75013 Paris , France
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14
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Reecht G, Krane N, Lotze C, Franke KJ. π-Radical Formation by Pyrrolic H Abstraction of Phthalocyanine Molecules on Molybdenum Disulfide. ACS NANO 2019; 13:7031-7035. [PMID: 31136150 DOI: 10.1021/acsnano.9b02117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
For a molecular radical to be stable, the environment needs to be inert. Furthermore, an unpaired electron is less likely to react chemically when it is placed in an extended orbital. Here, we use the tip of a scanning tunneling microscope to abstract one of the pyrrolic hydrogen atoms from phthalocyanine (H2Pc) deposited on a single layer of molybdenum disulfide (MoS2) on Au(111). We show the successful dissociation reaction by current-induced three-level fluctuations reflecting the inequivalent positions of the remaining H atom in the pyrrole center. Tunneling spectroscopy reveals two narrow resonances inside the semiconducting energy gap of MoS2 with their spatial extent resembling the highest occupied molecular orbital (HOMO) of H2Pc. By comparison to simple density functional calculations of the isolated molecule, we show that these correspond to a single occupation of the Coulomb-split highest molecular orbital of HPc. We conclude that the dangling σ bond after N-H bond cleavage is filled by an electron from the delocalized HOMO. The extended nature of the HOMO together with the inert nature of the MoS2 layer favors the stabilization of this radical state.
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Affiliation(s)
- Gaël Reecht
- Fachbereich Physik , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
| | - Nils Krane
- Fachbereich Physik , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
| | - Christian Lotze
- Fachbereich Physik , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
| | - Katharina J Franke
- Fachbereich Physik , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
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15
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Bocquet M, Lorente N, Berndt R, Gruber M. Spin in a Closed‐Shell Organic Molecule on a Metal Substrate Generated by a Sigmatropic Reaction. Angew Chem Int Ed Engl 2019; 58:821-824. [PMID: 30422385 DOI: 10.1002/anie.201812121] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Indexed: 11/07/2022]
Affiliation(s)
- Marie‐Laure Bocquet
- PASTEURDépartement de chimieÉcole normale supérieurePSL UniversitySorbonne UniversitéCNRS 75005 Paris France
| | - Nicolas Lorente
- Centro de Fısica de Materiales CFM/MPC (CSIC-UPV/EHU) Paseo Manuel de Lardizabal 5 20018 Donostia-San Sebastian Spain
- Donostia International Physics Center (DIPC) Paseo Manuel de Lardizabal 4 20018 Donostia-San Sebastian Spain
| | - Richard Berndt
- Institut für Experimentelle und Angewandte PhysikChristian-Albrechts-Universität 24098 Kiel Germany
| | - Manuel Gruber
- Institut für Experimentelle und Angewandte PhysikChristian-Albrechts-Universität 24098 Kiel Germany
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16
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Bocquet M, Lorente N, Berndt R, Gruber M. Spin in a Closed‐Shell Organic Molecule on a Metal Substrate Generated by a Sigmatropic Reaction. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201812121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Marie‐Laure Bocquet
- PASTEURDépartement de chimieÉcole normale supérieurePSL UniversitySorbonne UniversitéCNRS 75005 Paris France
| | - Nicolas Lorente
- Centro de Fısica de Materiales CFM/MPC (CSIC-UPV/EHU) Paseo Manuel de Lardizabal 5 20018 Donostia-San Sebastian Spain
- Donostia International Physics Center (DIPC) Paseo Manuel de Lardizabal 4 20018 Donostia-San Sebastian Spain
| | - Richard Berndt
- Institut für Experimentelle und Angewandte PhysikChristian-Albrechts-Universität 24098 Kiel Germany
| | - Manuel Gruber
- Institut für Experimentelle und Angewandte PhysikChristian-Albrechts-Universität 24098 Kiel Germany
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17
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Kügel J, Leisegang M, Bode M. Imprinting Directionality into Proton Transfer Reactions of an Achiral Molecule. ACS NANO 2018; 12:8733-8738. [PMID: 30086226 DOI: 10.1021/acsnano.8b04868] [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
Directionality is key for the functionality of molecular machines, which is often achieved by built-in structural chiralities. Here, we present a scanning tunneling microscopy study of achiral H2Pc and HPc molecules that acquire chirality by adsorption onto a Ag(100) surface. The adsorption-geometry-induced chirality is caused by a -29° (+29°) rotation of the molecules with respect to the [011] substrate direction, resulting in tautomerization processes that preferentially occur in a clockwise (counterclockwise) direction. The directionality is found to be independent of the particular energy and location of charge carrier injection. In contrast to built-in structural chiralities that are fixed by the molecular structure, the direction of proton motion in HPc on Ag(100) can be inverted by a rotation of the molecule on the substrate.
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Affiliation(s)
- Jens Kügel
- Physikalisches Institut, Experimentelle Physik II , Universität Würzburg, Am Hubland , 97074 Würzburg , Germany
| | - Markus Leisegang
- Physikalisches Institut, Experimentelle Physik II , Universität Würzburg, Am Hubland , 97074 Würzburg , Germany
| | - Matthias Bode
- Physikalisches Institut, Experimentelle Physik II , Universität Würzburg, Am Hubland , 97074 Würzburg , Germany
- Wilhelm Conrad Röntgen-Center for Complex Material Systems (RCCM) , Universität Würzburg, Am Hubland , D-97074 Würzburg , Germany
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18
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Garrido Torres JA, Simpson GJ, Adams CJ, Früchtl HA, Schaub R. On-Demand Final State Control of a Surface-Bound Bistable Single Molecule Switch. NANO LETTERS 2018; 18:2950-2956. [PMID: 29613810 DOI: 10.1021/acs.nanolett.8b00336] [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
Modern electronic devices perform their defined action because of the complete reliability of their individual active components (transistors, switches, diodes, and so forth). For instance, to encode basic computer units (bits) an electrical switch can be used. The reliability of the switch ensures that the desired outcome (the component's final state, 0 or 1) can be selected with certainty. No practical data storage device would otherwise exist. This reliability criterion will necessarily need to hold true for future molecular electronics to have the opportunity to emerge as a viable miniaturization alternative to our current silicon-based technology. Molecular electronics target the use of single-molecules to perform the actions of individual electronic components. On-demand final state control over a bistable unimolecular component has therefore been one of the main challenges in the past decade (1-5) but has yet to be achieved. In this Letter, we demonstrate how control of the final state of a surface-supported bistable single molecule switch can be realized. On the basis of the observations and deductions presented here, we further suggest an alternative strategy to achieve final state control in unimolecular bistable switches.
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Affiliation(s)
- José A Garrido Torres
- EaStCHEM and School of Chemistry , University of St. Andrews , St. Andrews KY16 9ST , United Kingdom
| | - Grant J Simpson
- EaStCHEM and School of Chemistry , University of St. Andrews , St. Andrews KY16 9ST , United Kingdom
| | - Christopher J Adams
- School of Chemistry , University of Bristol , Bristol BS8 1TS , United Kingdom
| | - Herbert A Früchtl
- EaStCHEM and School of Chemistry , University of St. Andrews , St. Andrews KY16 9ST , United Kingdom
| | - Renald Schaub
- EaStCHEM and School of Chemistry , University of St. Andrews , St. Andrews KY16 9ST , United Kingdom
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19
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Kumagai T, Ladenthin JN, Litman Y, Rossi M, Grill L, Gawinkowski S, Waluk J, Persson M. Quantum tunneling in real space: Tautomerization of single porphycene molecules on the (111) surface of Cu, Ag, and Au. J Chem Phys 2018; 148:102330. [DOI: 10.1063/1.5004602] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Takashi Kumagai
- Department of Physical Chemistry, Fritz-Haber Institute of the Max-Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - Janina N. Ladenthin
- Department of Physical Chemistry, Fritz-Haber Institute of the Max-Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - Yair Litman
- Theory Department, Fritz-Haber Institute of the Max-Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - Mariana Rossi
- Theory Department, Fritz-Haber Institute of the Max-Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - Leonhard Grill
- Department of Physical Chemistry, University of Graz, Heinrichstrasse 28, 8010 Graz, Austria
| | - Sylwester Gawinkowski
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, Warsaw 01-224, Poland
| | - Jacek Waluk
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, Warsaw 01-224, Poland
- Faculty of Mathematics and Natural Sciences, College of Science, Cardinal Stefan Wyszyński University, Dewajtis 5, 01-815 Warsaw, Poland
| | - Mats Persson
- Surface Science Research Centre and Department of Chemistry, University of Liverpool, Liverpool L69 3BX, United Kingdom
- Department of Physics, Chalmers University of Technology, SE 41296 Göteborg, Sweden
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20
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Leisegang M, Kügel J, Klein L, Bode M. Analyzing the Wave Nature of Hot Electrons with a Molecular Nanoprobe. NANO LETTERS 2018; 18:2165-2171. [PMID: 29486560 DOI: 10.1021/acs.nanolett.8b00465] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We report on a novel method, the molecular nanoprobe (MONA) technique, which allows us to measure the nanoscale quasiparticle transport between two arbitrary surface points. In these experiments, hot electrons are injected into the sample surface from the probe tip of a scanning tunneling microscope (STM) and detected by tautomerization switching events of a single deprotonated phthalocyanine (H2Pc) molecule. By making use of atom-by-atom-engineered interferometers on a Ag(111) surface, we demonstrate that the quantum-mechanical wave nature of hot electrons leads to characteristic oscillations of the molecule tautomerization probability. Two interferometers can be combined to build an energy-dependent selector, which allows it to selectively switch one out of two molecules without changing the position of the STM tip. The MONA technique is compared with conventional d I/d U measurements, where the injection and detection point of hot electrons is intrinsically tied to the same tip location.
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Affiliation(s)
- Markus Leisegang
- Physikalisches Institut, Experimentelle Physik II , Universität Würzburg , Am Hubland , 97074 Würzburg , Germany
| | - Jens Kügel
- Physikalisches Institut, Experimentelle Physik II , Universität Würzburg , Am Hubland , 97074 Würzburg , Germany
| | - Lucas Klein
- Physikalisches Institut, Experimentelle Physik II , Universität Würzburg , Am Hubland , 97074 Würzburg , Germany
| | - Matthias Bode
- Physikalisches Institut, Experimentelle Physik II , Universität Würzburg , Am Hubland , 97074 Würzburg , Germany
- Wilhelm Conrad Röntgen-Center for Complex Material Systems (RCCM) , Universität Würzburg , Am Hubland , D-97074 Würzburg , Germany
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21
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Kügel J, Leisegang M, Böhme M, Krönlein A, Sixta A, Bode M. Remote Single-Molecule Switching: Identification and Nanoengineering of Hot Electron-Induced Tautomerization. NANO LETTERS 2017; 17:5106-5112. [PMID: 28732159 DOI: 10.1021/acs.nanolett.7b02419] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Molecular electronics where single molecules perform basic functionalities of digital circuits is a fascinating concept that one day may augment or even replace nowadays semiconductor technologies. The tautomerization of molecules, that is, the bistable functional position of hydrogen protons within an organic frame, has recently been intensively discussed as a potential avenue toward nanoscale switches. It has been shown that tautomerization can be triggered locally or nonlocally, that is, by a scanning tunneling microscope (STM) tip positioned directly above or in close vicinity to the molecule. Whereas consensus exists that local switching is caused by inelastic electrons that excite vibrational molecular modes, the detailed processes responsible for nonlocal tautomerization switching and, even more important in the context of this work, methods to control, engineer, and potentially utilize this process are largely unknown. Here, we demonstrate for dehydrogenated H2Pc molecules on Ag(111) how to controllably decrease or increase the probability of nonlocal, hot electron-induced tautomerization by atom-by-atom designed Ag nanostructures. We show that Ag atom walls act as potential barriers that exponentially damp the hot electron current between the injection point and the molecule, reducing the switching probability by up to 83% for a four-atom wide wall. By placing the molecule in one and the STM tip in the other focal point of an elliptical nanostructure, we could coherently focus hot electrons onto the molecule that led to an almost tripled switching probability. Furthermore, single and double slit experiment based on silver atom structures were used to characterize the spatial extension of hot electron packets. The absence of any detectable interference pattern suggests that the coherence length of the hot electrons that trigger tautomerization processes is rather short. Our results demonstrate that the tautomerization switching of single molecules can remotely be controlled by utilizing suitable nanostructures and may pave the way for designing new tautomerization-based switches.
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Affiliation(s)
- Jens Kügel
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg , Am Hubland, 97074 Würzburg, Germany
| | - Markus Leisegang
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg , Am Hubland, 97074 Würzburg, Germany
| | - Markus Böhme
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg , Am Hubland, 97074 Würzburg, Germany
| | - Andreas Krönlein
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg , Am Hubland, 97074 Würzburg, Germany
| | - Aimee Sixta
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg , Am Hubland, 97074 Würzburg, Germany
- University of Texas at Austin , Austin, Texas 78712, United States
| | - Matthias Bode
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg , Am Hubland, 97074 Würzburg, Germany
- Wilhelm Conrad Röntgen-Center for Complex Material Systems (RCCM), Universität Würzburg , Am Hubland, D-97074 Würzburg, Germany
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