1
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Dehiwala Liyanage C, Ortiz-Garcia JJ, Struckmeier A, McCoy CL, Kienzler MA, Quardokus RC. A Scanning Tunneling Microscopy Study of the Photoisomerization of Diazocine. J Phys Chem Lett 2024; 15:4082-4087. [PMID: 38587451 DOI: 10.1021/acs.jpclett.4c00096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Azobenzenes are fascinating molecular machines that can reversibly transform between two isomeric forms by an external stimulus. Diazocine, a type of bridged azobenzene, has been shown to possess enhanced photoexcitation properties. Due to the distortion caused by the ethyl bridge in the E-isomer, the Z-form becomes the thermodynamically stable configuration. Despite a comprehensive understanding of its photophysical properties, there is still much to learn about the behavior of diazocine on a metal surface. Here we show the operando photoswitching of diazocine molecules deposited directly on a Au(111) surface using scanning tunneling microscopy. Molecules were shown to aggregate into disordered islands with edge sites being susceptible to photon-induced movement. A few molecules were shown to undergo directional movement under UV irradiation with the motion reversed under blue light exposure. These findings contribute new insight into the activity of single and ensemble molecular systems toward purposefully guided motion.
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Affiliation(s)
| | - José J Ortiz-Garcia
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Annalena Struckmeier
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Christian L McCoy
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Michael A Kienzler
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Rebecca C Quardokus
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
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2
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Bejarano F, Gutiérrez D, Catalán-Toledo J, Roca-Sanjuán D, Gierschner J, Veciana J, Mas-Torrent M, Rovira C, Crivillers N. Photoswitching activation of a ferrocenyl-stilbene analogue by its covalent grafting to gold. Phys Chem Chem Phys 2022; 24:6185-6192. [PMID: 35229090 DOI: 10.1039/d1cp05012e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Until now, surface-deposited stilbenes have been much less studied than other photochromic systems. Here, an asymmetrically substituted styrene incorporating a redox-active ferrocene moiety and a terminal alkyne group has been synthesised to investigate its photoisomerization in solution, and upon the formation of chemisorbed self-assembled monolayers through a carbon-gold bond formation. Charge transport measurements across the monolayers reveal that upon chemical linkage to the gold substrate there is an alteration of the isomerization pathway, which favours the trans to cis conversion, which is not observed in solution. The experimental observations are interpreted based on quantum chemistry calculations.
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Affiliation(s)
- Francesc Bejarano
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) and CIBER-BBN, Campus de la UAB, 08193 Bellaterra, Spain.
| | - Diego Gutiérrez
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) and CIBER-BBN, Campus de la UAB, 08193 Bellaterra, Spain. .,Leitat Technological Center (LEITAT), Carrer Innovació, 2, 08225 Terrassa, Spain
| | - José Catalán-Toledo
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) and CIBER-BBN, Campus de la UAB, 08193 Bellaterra, Spain.
| | - Daniel Roca-Sanjuán
- Institute of Molecular Science, University of Valencia, P.O. Box 22085, ES-46071 Valencia, Spain
| | - Johannes Gierschner
- Madrid Institute for Advanced Studies, IMDEA Nanoscience, Calle Faraday 9, Campus Cantoblanco, 28049 Madrid, Spain.
| | - Jaume Veciana
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) and CIBER-BBN, Campus de la UAB, 08193 Bellaterra, Spain.
| | - Marta Mas-Torrent
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) and CIBER-BBN, Campus de la UAB, 08193 Bellaterra, Spain.
| | - Concepció Rovira
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) and CIBER-BBN, Campus de la UAB, 08193 Bellaterra, Spain.
| | - Núria Crivillers
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) and CIBER-BBN, Campus de la UAB, 08193 Bellaterra, Spain.
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3
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Nacci C, Schied M, Civita D, Magnano E, Nappini S, Píš I, Grill L. Thermal- vs Light-Induced On-Surface Polymerization. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2021; 125:22554-22561. [PMID: 34712378 PMCID: PMC8543439 DOI: 10.1021/acs.jpcc.1c06914] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 09/21/2021] [Indexed: 06/13/2023]
Abstract
On-surface polymerization is a powerful bottom-up approach that allows for the growth of covalent architectures with defined properties using the two-dimensional confinement of a highly defined single-crystal surface. Thermal heating is the preferred approach to initiate the reaction, often via cleavage of halogen substituents from the molecular building blocks. Light represents an alternative stimulus but has, thus far, only rarely been used. Here, we present a direct comparison of on-surface polymerization of dibromo-anthracene molecules, induced either thermally or by light, and study the differences between the two approaches. Insight is obtained by a combination of scanning tunneling microscopy, locally studying the polymer shape and size, and X-ray photoelectron spectroscopy, which identifies bond formation by averaging over large surface areas. While the polymer length increases slowly with the sample heating temperature, illumination promotes only the formation of short covalent structures, independent of the duration of light exposure. Moreover, irradiation with UV light at different sample temperatures highlights the important role of molecular diffusion across the surface.
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Affiliation(s)
- Christophe Nacci
- Department
of Physical Chemistry, University of Graz, 8010 Graz, Austria
| | - Monika Schied
- Department
of Physical Chemistry, University of Graz, 8010 Graz, Austria
| | - Donato Civita
- Department
of Physical Chemistry, University of Graz, 8010 Graz, Austria
| | - Elena Magnano
- IOM
CNR Laboratorio TASC, 34149 Basovizza, TS, Italy
- Department
of Physics, University of Johannesburg, P.O. Box 524, Auckland Park, Johannesburg 2006, South Africa
| | | | - Igor Píš
- IOM
CNR Laboratorio TASC, 34149 Basovizza, TS, Italy
| | - Leonhard Grill
- Department
of Physical Chemistry, University of Graz, 8010 Graz, Austria
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4
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Zhang X, Zhou D, Wang X, Zhou J, Li J, Zhang M, Shen Y, Chu H, Qu Y. Overcoming the Deactivation of Pt/CNT by Introducing CeO2 for Selective Base-Free Glycerol-to-Glyceric Acid Oxidation. ACS Catal 2020. [DOI: 10.1021/acscatal.9b05559] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Xueqiong Zhang
- College of Chemistry and Chemical Engineering, Inner Mongolia Engineering and Technology Research Center for Catalytic Conversion and Utilization of Carbon Resource Molecules, Inner Mongolia University, Hohhot 010021, China
| | - Dan Zhou
- College of Chemistry and Chemical Engineering, Inner Mongolia Engineering and Technology Research Center for Catalytic Conversion and Utilization of Carbon Resource Molecules, Inner Mongolia University, Hohhot 010021, China
| | - Xiaojing Wang
- College of Chemistry and Chemical Engineering, Inner Mongolia Engineering and Technology Research Center for Catalytic Conversion and Utilization of Carbon Resource Molecules, Inner Mongolia University, Hohhot 010021, China
| | - Jian Zhou
- College of Chemistry and Chemical Engineering, Inner Mongolia Engineering and Technology Research Center for Catalytic Conversion and Utilization of Carbon Resource Molecules, Inner Mongolia University, Hohhot 010021, China
| | - Jiefei Li
- College of Chemistry and Chemical Engineering, Inner Mongolia Engineering and Technology Research Center for Catalytic Conversion and Utilization of Carbon Resource Molecules, Inner Mongolia University, Hohhot 010021, China
| | - Mingkai Zhang
- Frontier Institute of Science and Technology, Xi’an Jiaotong University, Xi’an, 710049, China
| | - Yihong Shen
- PetroChina Petrochemical Research Institute, Beijing 102206, China
| | - Haibin Chu
- College of Chemistry and Chemical Engineering, Inner Mongolia Engineering and Technology Research Center for Catalytic Conversion and Utilization of Carbon Resource Molecules, Inner Mongolia University, Hohhot 010021, China
| | - Yongquan Qu
- Frontier Institute of Science and Technology, Xi’an Jiaotong University, Xi’an, 710049, China
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5
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Stein A, Rolf D, Lotze C, Czekelius C, Franke KJ, Tegeder P. Electronic structure of an iron porphyrin derivative on Au(1 1 1). JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:044002. [PMID: 30523801 DOI: 10.1088/1361-648x/aaf296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Surface-bound porphyrins are promising candidates for molecular switches, electronics and spintronics. Here, we studied the structural and the electronic properties of Fe-tetra-pyridil-porphyrin adsorbed on Au(1 1 1) in the monolayer regime. We combined scanning tunneling microscopy/spectroscopy, ultraviolet photoemission, and two-photon photoemission to determine the energy levels of the frontier molecular orbitals. We also resolved an excitonic state with a binding energy of 420 meV, which allowed us to compare the electronic transport gap with the optical gap.
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Affiliation(s)
- Arnulf Stein
- Physikalisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
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6
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Maurer RJ, Reuter K. Computational design of metal-supported molecular switches: transient ion formation during light- and electron-induced isomerisation of azobenzene. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:044003. [PMID: 30523934 DOI: 10.1088/1361-648x/aaf0e1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In molecular nanotechnology, a single molecule is envisioned to act as the basic building block of electronic devices. Such devices may be of special interest for organic photovoltaics, data storage, and smart materials. However, more often than not the molecular function is quenched upon contact with a conducting support. Trial-and-error-based decoupling strategies via molecular functionalisation and change of substrate have in many instances proven to yield unpredictable results. The adsorbate-substrate interactions that govern the function can be understood with the help of first-principles simulation. Employing dispersion-corrected density-functional theory (DFT) and linear expansion delta-self-consistent-field DFT, the electronic structure of a prototypical surface-adsorbed functional molecule, namely azobenzene adsorbed to (1 1 1) single crystal facets of copper, silver and gold, is investigated and the main reasons for the loss or survival of the switching function upon adsorption are identified. The light-induced switching ability of a functionalised derivative of azobenzene on Au(1 1 1) and azobenzene on Ag(1 1 1) and Au(1 1 1) is assessed based on the excited-state potential energy landscapes of their transient molecular ions, which are believed to be the main intermediates of the experimentally observed isomerisation reaction. We provide a rationalisation of the experimentally observed function or lack thereof that connects to the underlying chemistry of the metal-surface interaction and provides insights into general design strategies for complex light-driven reactions at metal surfaces.
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Affiliation(s)
- Reinhard J Maurer
- Department of Chemistry, University of Warwick, Gibbet Hill Road, CV4 7AL, Coventry, United Kingdom
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7
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Nacci C, Baroncini M, Credi A, Grill L. Reversible Photoswitching and Isomer-Dependent Diffusion of Single Azobenzene Tetramers on a Metal Surface. Angew Chem Int Ed Engl 2018; 57:15034-15039. [PMID: 30187995 PMCID: PMC6237119 DOI: 10.1002/anie.201806536] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Indexed: 11/07/2022]
Abstract
Azobenzene is a prototypical molecular switch that can be reversibly photoisomerized between the nearly planar and apolar trans form, and the distorted, polar cis form. Most studies related to azobenzene derivatives have focused on planar adsorbed molecules. We present herein the study of a three-dimensional shape-persistent molecular architecture consisting of four tetrahedrally arranged azobenzene units that is adsorbed on a Ag(111) surface. While the azobenzenes of the tripod in contact with the surface lost their switching ability, different isomers of the upright standing arm of the tetramer were obtained reversibly and efficiently by illumination at different wavelengths, revealing time constants of only a few minutes. Diffusion on the surface was dependent on the isomeric state-trans or cis-of the upright oriented azobenzene group. Hence, molecular mobility can be modulated by its isomeric state, which suggests that molecular growth processes could be controlled by external stimuli.
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Affiliation(s)
- Christophe Nacci
- Department of Physical ChemistryUniversity of GrazHeinrichstrasse 288010GrazAustria
| | - Massimo Baroncini
- Dipartimento di Scienze e Tecnologie Agro-AlimentariUniversità di BolognaViale Fanin 5040127BolognaItaly
- CLAN-Center for Light Activated NanostructuresIstituto ISOF-CNRvia Gobetti 10140129BolognaItaly
| | - Alberto Credi
- Dipartimento di Scienze e Tecnologie Agro-AlimentariUniversità di BolognaViale Fanin 5040127BolognaItaly
- CLAN-Center for Light Activated NanostructuresIstituto ISOF-CNRvia Gobetti 10140129BolognaItaly
| | - Leonhard Grill
- Department of Physical ChemistryUniversity of GrazHeinrichstrasse 288010GrazAustria
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8
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Busson B, Dalstein L. Nonlinear optical response of a gold surface in the visible range: A study by two-color sum-frequency generation spectroscopy. III. Simulations of the experimental SFG intensities. J Chem Phys 2018; 149:154701. [DOI: 10.1063/1.5047098] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- B. Busson
- Laboratoire de Chimie Physique, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Bâtiment 201 P2, 91405 Orsay, France
| | - L. Dalstein
- Laboratoire de Chimie Physique, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Bâtiment 201 P2, 91405 Orsay, France
- Department of Chemistry, School of Chemical Science and Engineering, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden
- Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
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9
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Nacci C, Baroncini M, Credi A, Grill L. Reversible Photoswitching and Isomer‐Dependent Diffusion of Single Azobenzene Tetramers on a Metal Surface. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201806536] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Christophe Nacci
- Department of Physical ChemistryUniversity of Graz Heinrichstrasse 28 8010 Graz Austria
| | - Massimo Baroncini
- Dipartimento di Scienze e Tecnologie Agro-AlimentariUniversità di Bologna Viale Fanin 50 40127 Bologna Italy
- CLAN-Center for Light Activated NanostructuresIstituto ISOF-CNR via Gobetti 101 40129 Bologna Italy
| | - Alberto Credi
- Dipartimento di Scienze e Tecnologie Agro-AlimentariUniversità di Bologna Viale Fanin 50 40127 Bologna Italy
- CLAN-Center for Light Activated NanostructuresIstituto ISOF-CNR via Gobetti 101 40129 Bologna Italy
| | - Leonhard Grill
- Department of Physical ChemistryUniversity of Graz Heinrichstrasse 28 8010 Graz Austria
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10
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Jaekel S, Richter A, Lindner R, Bechstein R, Nacci C, Hecht S, Kühnle A, Grill L. Reversible and Efficient Light-Induced Molecular Switching on an Insulator Surface. ACS NANO 2018; 12:1821-1828. [PMID: 29316393 DOI: 10.1021/acsnano.7b08624] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Prototypical molecular switches such as azobenzenes exhibit two states, i.e., trans and cis, with different characteristic physical properties. In recent years various derivatives were investigated on metallic surfaces. However, bulk insulators as supporting substrate reveal important advantages since they allow electronic decoupling from the environment, which is key to control the switching properties. Here, we report on the light-induced isomerization of an azobenzene derivative on a bulk insulator surface, in this case calcite (101̅4), studied by atomic force microscopy with submolecular resolution. Surprisingly, cis isomers appear on the surface already directly after preparation, indicating kinetic trapping. The photoisomerization process is reversible, as the use of different light sources results in specific molecular assemblies of each isomer. The process turns out to be very efficient and even comparable to molecules in solution, which we assign to the rather weak molecular interaction with the insulator surface, in contrast to metals.
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Affiliation(s)
- Simon Jaekel
- Department of Physical Chemistry, University of Graz , Heinrichstrasse 28, Graz 8010, Austria
| | - Antje Richter
- Department of Physical Chemistry, University of Mainz , Duesbergweg 10-14, Mainz 55122, Germany
| | - Robert Lindner
- Department of Physical Chemistry, University of Mainz , Duesbergweg 10-14, Mainz 55122, Germany
| | - Ralf Bechstein
- Department of Physical Chemistry, University of Mainz , Duesbergweg 10-14, Mainz 55122, Germany
| | - Christophe Nacci
- Department of Physical Chemistry, University of Graz , Heinrichstrasse 28, Graz 8010, Austria
| | - Stefan Hecht
- Department of Chemistry, Humboldt-Universität zu Berlin , Brook-Taylor-Straße 2, Berlin 10099, Germany
| | - Angelika Kühnle
- Department of Physical Chemistry, University of Mainz , Duesbergweg 10-14, Mainz 55122, Germany
| | - Leonhard Grill
- Department of Physical Chemistry, University of Graz , Heinrichstrasse 28, Graz 8010, Austria
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11
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Carbone F, Hengsberger M, Castiglioni L, Osterwalder J. Femtosecond manipulation of spins, charges, and ions in nanostructures, thin films, and surfaces. Struct Dyn 2017; 4:061504. [PMID: 29308416 PMCID: PMC5736395 DOI: 10.1063/1.4995541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 09/05/2017] [Indexed: 11/15/2022] Open
Affiliation(s)
- F. Carbone
- Ecole Polytechnique Fédérale de Lausanne, Institute of Physics, Laboratory for Ultrafast Microscopy and Electron Scattering (LUMES), EPFL Campus, Lausanne, Dorigny CH-1015, Switzerland
| | - M. Hengsberger
- Department of Physics, University of Zurich, CH-8057 Zurich, Switzerland
| | - L. Castiglioni
- Department of Physics, University of Zurich, CH-8057 Zurich, Switzerland
| | - J. Osterwalder
- Department of Physics, University of Zurich, CH-8057 Zurich, Switzerland
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12
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Stremlau S, Maass F, Tegeder P. Adsorption and switching properties of nitrospiropyran on Bi(1 1 4). JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:314004. [PMID: 28604364 DOI: 10.1088/1361-648x/aa78be] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Spiropyrans are prototype molecular switches, which undergo a reversible photoinduced ring-opening/-closure reaction between the closed three-dimensional spiropyran (SP) and the open, planar merocyanine (MC) form. In solution the SP isomer is the thermodynamically stable form. Using high resolution electron energy loss spectroscopy, we resolve a thermally-activated irreversible ring-opening reaction of nitrospiropyran resulting in the MC form for coverages above one monolayer. Thus, the situation found in solution is reversed for the adsorbed molecules, since the MC form is more stable due to the modified energetics by the presence of the substrate. In addition, illumination with blue light (445 nm) induced also the ring-opening, while the photostimulated back-reaction could not be observed. The photoisomerization is driven by a substrate-mediated process, i.e. a charge transfer from the substrate into molecular states. The situation changes completely in the monolayer regime. Neither a thermally-assisted nor a photoinduced ring-opening reaction has been identified. We ascribe the suppression to sterical effects stabilizing the SP form due to the surface structure of Bi(1 1 4), which consists of straight atomic rows separated by rough valleys.
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Affiliation(s)
- Stephan Stremlau
- Ruprecht-Karls-Universität Heidelberg, Physikalisch-Chemisches Institut, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
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13
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Tuca E, Paci I. Computer simulations of self-assembled energy materials. MOLECULAR SIMULATION 2017. [DOI: 10.1080/08927022.2017.1306063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- E. Tuca
- Department of Chemistry, University of Victoria, Victoria, Canada
| | - I. Paci
- Department of Chemistry, University of Victoria, Victoria, Canada
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14
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Schuler A, Greif M, Seitsonen AP, Mette G, Castiglioni L, Osterwalder J, Hengsberger M. Sensitivity of photoelectron diffraction to conformational changes of adsorbed molecules: Tetra-tert-butyl-azobenzene/Au(111). STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2017; 4:015101. [PMID: 28217715 PMCID: PMC5291794 DOI: 10.1063/1.4975594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 01/23/2017] [Indexed: 06/06/2023]
Abstract
Electron diffraction is a standard tool to investigate the atomic structure of surfaces, interfaces, and adsorbate systems. In particular, photoelectron diffraction is a promising candidate for real-time studies of structural dynamics combining the ultimate time resolution of optical pulses and the high scattering cross-sections for electrons. In view of future time-resolved experiments from molecular layers, we studied the sensitivity of photoelectron diffraction to conformational changes of only a small fraction of molecules in a monolayer adsorbed on a metallic substrate. 3,3',5,5'-tetra-tert-butyl-azobenzene served as test case. This molecule can be switched between two isomers, trans and cis, by absorption of ultraviolet light. X-ray photoelectron diffraction patterns were recorded from tetra-tert-butyl-azobenzene/Au(111) in thermal equilibrium at room temperature and compared to patterns taken in the photostationary state obtained by exposing the surface to radiation from a high-intensity helium discharge lamp. Difference patterns were simulated by means of multiple-scattering calculations, which allowed us to determine the fraction of molecules that underwent isomerization.
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Affiliation(s)
- A Schuler
- Physik-Institut, Universität Zürich , Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - M Greif
- Physik-Institut, Universität Zürich , Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - A P Seitsonen
- Département de Chimie, Ecole Normale Surpérieure , 24, Rue Lhomond, 75005 Paris, France
| | | | - L Castiglioni
- Physik-Institut, Universität Zürich , Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - J Osterwalder
- Physik-Institut, Universität Zürich , Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - M Hengsberger
- Physik-Institut, Universität Zürich , Winterthurerstrasse 190, 8057 Zürich, Switzerland
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15
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Saywell A, Bakker A, Mielke J, Kumagai T, Wolf M, García-López V, Chiang PT, Tour JM, Grill L. Light-Induced Translation of Motorized Molecules on a Surface. ACS NANO 2016; 10:10945-10952. [PMID: 27783488 DOI: 10.1021/acsnano.6b05650] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Molecular machines are a key component in the vision of molecular nanotechnology and have the potential to transport molecular species and cargo on surfaces. The motion of such machines should be triggered remotely, ultimately allowing a large number of molecules to be propelled by a single source, with light being an attractive stimulus. Here, we report upon the photoinduced translation of molecular machines across a surface by characterizing single molecules before and after illumination. Illumination of molecules containing a motor unit results in an enhancement in the diffusion of the molecules. The effect vanishes if an incompatible photon energy is used or if the motor unit is removed from the molecule, revealing that the enhanced motion is due to the presence of the wavelength-sensitive motor in each molecule.
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Affiliation(s)
- Alex Saywell
- Department of Physical Chemistry, Fritz-Haber Institute of the Max-Planck Society , Berlin 14195, Germany
- School of Physics and Astronomy, The University of Nottingham , Nottingham NG7 2RD, United Kingdom
| | - Anne Bakker
- Department of Physical Chemistry, Fritz-Haber Institute of the Max-Planck Society , Berlin 14195, Germany
| | - Johannes Mielke
- Department of Physical Chemistry, Fritz-Haber Institute of the Max-Planck Society , Berlin 14195, Germany
| | - Takashi Kumagai
- Department of Physical Chemistry, Fritz-Haber Institute of the Max-Planck Society , Berlin 14195, Germany
| | - Martin Wolf
- Department of Physical Chemistry, Fritz-Haber Institute of the Max-Planck Society , Berlin 14195, Germany
| | - Víctor García-López
- Departments of Chemistry and Materials Science and NanoEngineering and the Smalley Institute for Nanoscale Science and Technology, Rice University , Houston, Texas 77005, United States
| | - Pinn-Tsong Chiang
- Departments of Chemistry and Materials Science and NanoEngineering and the Smalley Institute for Nanoscale Science and Technology, Rice University , Houston, Texas 77005, United States
| | - James M Tour
- Departments of Chemistry and Materials Science and NanoEngineering and the Smalley Institute for Nanoscale Science and Technology, Rice University , Houston, Texas 77005, United States
| | - Leonhard Grill
- Department of Physical Chemistry, Fritz-Haber Institute of the Max-Planck Society , Berlin 14195, Germany
- Department of Physical Chemistry, University of Graz , Heinrichstrasse 28, Graz 8010, Austria
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16
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Schulze M, Utecht M, Moldt T, Przyrembel D, Gahl C, Weinelt M, Saalfrank P, Tegeder P. Nonlinear optical response of photochromic azobenzene-functionalized self-assembled monolayers. Phys Chem Chem Phys 2015; 17:18079-86. [PMID: 26100382 DOI: 10.1039/c5cp03093e] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The combination of photochromic and nonlinear optical (NLO) properties of azobenzene-functionalized self-assembled monolayers (SAMs) constitutes an intriguing step towards novel photonic and optoelectronic devices. By utilizing the second-order NLO process of second harmonic generation (SHG), supported by density-functional theory and correlated wave function method calculations, we demonstrate that the photochromic interface provides the necessary prerequisites en route towards possible future technical applications: we find a high NLO contrast on the order of 16% between the switching states. These are furthermore accessible reversibly and with high efficiencies in terms of cross sections on the order of 10(-18) cm(2) for both photoisomerization reactions, i.e., drivable by means of low-power LED light sources. Finally, both photostationary states (PSSs) are thermally stable at ambient conditions.
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Affiliation(s)
- Michael Schulze
- Physikalisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, 69120 Heildeberg, Germany.
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17
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Schulze M, Utecht M, Hebert A, Rück-Braun K, Saalfrank P, Tegeder P. Reversible Photoswitching of the Interfacial Nonlinear Optical Response. J Phys Chem Lett 2015; 6:505-9. [PMID: 26261971 DOI: 10.1021/jz502477m] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Incorporating photochromic molecules into organic/inorganic hybrid materials may lead to photoresponsive systems. In such systems, the second-order nonlinear properties can be controlled via external stimulation with light at an appropriate wavelength. By creating photochromic molecular switches containing self-assembled monolayers on Si(111), we can demonstrate efficient reversible switching, which is accompanied by a pronounced modulation of the nonlinear optical (NLO) response of the system. The concept of utilizing functionalized photoswitchable Si surfaces could be a way for the generation of two-dimensional NLO switching materials, which are promising for applications in photonic and optoelectronic devices.
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Affiliation(s)
- Michael Schulze
- †Physikalisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
- ‡Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Manuel Utecht
- ¶Institut für Chemie, Theoretische Chemie, Universität Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany
| | - Andreas Hebert
- §Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Karola Rück-Braun
- §Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Peter Saalfrank
- ¶Institut für Chemie, Theoretische Chemie, Universität Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany
| | - Petra Tegeder
- †Physikalisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
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18
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Bazarnik M, Jurczyszyn L, Czajka R, Morgenstern K. Mechanism of a molecular photo-switch adsorbed on Si(100). Phys Chem Chem Phys 2015; 17:5366-71. [DOI: 10.1039/c4cp04353g] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present a combined scanning tunneling microscopy and density functional theory study of a compact molecular photoswitch on a Si(100) surface.
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Affiliation(s)
- Maciej Bazarnik
- Institute of Physics
- Poznan University of Technology
- 60-965 Poznan
- Poland
- Insitute of Applied Physics and Interdisciplinary Nanoscience Center Hamburg
| | - Leszek Jurczyszyn
- Institute of Experimental Physics
- University of Wroclaw
- 50-204 Wroclaw
- Poland
| | - Ryszard Czajka
- Institute of Physics
- Poznan University of Technology
- 60-965 Poznan
- Poland
| | - Karina Morgenstern
- Chair of Physical Chemistry I
- Ruhr-Universität Bochum
- D-44801 Bochum
- Germany
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19
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Zhang JL, Zhong JQ, Lin JD, Hu WP, Wu K, Xu GQ, Wee ATS, Chen W. Towards single molecule switches. Chem Soc Rev 2015; 44:2998-3022. [DOI: 10.1039/c4cs00377b] [Citation(s) in RCA: 247] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Scanning tunneling microscope (STM) controlled reversible switching of a single-dipole molecule imbedded in hydrogen-bonded binary molecular networks on graphite.
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Affiliation(s)
- Jia Lin Zhang
- Department of Chemistry
- National University of Singapore
- Singapore
- Department of Physics
- National University of Singapore
| | - Jian Qiang Zhong
- Department of Chemistry
- National University of Singapore
- Singapore
- Department of Physics
- National University of Singapore
| | - Jia Dan Lin
- Department of Chemistry
- National University of Singapore
- Singapore
- Department of Physics
- National University of Singapore
| | - Wen Ping Hu
- School of Science
- Tianjin University
- Tian Jin
- China
| | - Kai Wu
- Singapore-Peking University Research Center for a Sustainable Low-Carbon Future
- Singapore
- College of Chemistry and Molecular Engineering
- Peking University
- Beijing 100871
| | - Guo Qin Xu
- Department of Chemistry
- National University of Singapore
- Singapore
- Singapore-Peking University Research Center for a Sustainable Low-Carbon Future
- Singapore
| | | | - Wei Chen
- Department of Chemistry
- National University of Singapore
- Singapore
- Department of Physics
- National University of Singapore
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20
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Schulze M, Bronner C, Tegeder P. Adsorption energetics of azobenzenes on noble metal surfaces. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:355004. [PMID: 25077738 DOI: 10.1088/0953-8984/26/35/355004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Temperature-programmed desorption measurements have been applied to investigate the binding energies of four systems, namely the photochromic molecular compounds azobenzene and tetra-tert-butyl-azobenzene (TBA) adsorbed on the Au(1 1 1) and Ag(1 1 1) surfaces, respectively. The binding energy is a measure of the interaction strength between substrate and adsorbate. It therefore provides a suitable means for an investigation of the decoupling strategy pursued by adding the tert-butyl spacer groups and choosing the more inert gold substrate, which leads to TBA/Au(1 1 1), the only photoisomerizable system out of the four. Ironically, we find TBA/Au(1 1 1) to be the most strongly bound. The binding of TBA to Au(1 1 1) is almost 0.4 eV stronger than to Ag(1 1 1). On the other hand, azobenzene binds approximately equally strongly to both surfaces. These findings are consistent with and provide support for the recently proposed hybridization between the HOMO of TBA and the Au(1 1 1) d-band needed for the hole attachment which induces the isomerization.
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Affiliation(s)
- Michael Schulze
- Physikalisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany. Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
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21
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Otte FL, Lemke S, Schütt C, Krekiehn NR, Jung U, Magnussen OM, Herges R. Ordered Monolayers of Free-Standing Porphyrins on Gold. J Am Chem Soc 2014; 136:11248-51. [DOI: 10.1021/ja505563e] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Franziska L. Otte
- Otto-Diels-Institute for Organic
Chemistry and ‡Institute for Experimental and Applied
Physics, Christian-Albrechts-University of Kiel, 24098 Kiel, Germany
| | - Sonja Lemke
- Otto-Diels-Institute for Organic
Chemistry and ‡Institute for Experimental and Applied
Physics, Christian-Albrechts-University of Kiel, 24098 Kiel, Germany
| | - Christian Schütt
- Otto-Diels-Institute for Organic
Chemistry and ‡Institute for Experimental and Applied
Physics, Christian-Albrechts-University of Kiel, 24098 Kiel, Germany
| | - Nicolai R. Krekiehn
- Otto-Diels-Institute for Organic
Chemistry and ‡Institute for Experimental and Applied
Physics, Christian-Albrechts-University of Kiel, 24098 Kiel, Germany
| | - Ulrich Jung
- Otto-Diels-Institute for Organic
Chemistry and ‡Institute for Experimental and Applied
Physics, Christian-Albrechts-University of Kiel, 24098 Kiel, Germany
| | - Olaf M. Magnussen
- Otto-Diels-Institute for Organic
Chemistry and ‡Institute for Experimental and Applied
Physics, Christian-Albrechts-University of Kiel, 24098 Kiel, Germany
| | - Rainer Herges
- Otto-Diels-Institute for Organic
Chemistry and ‡Institute for Experimental and Applied
Physics, Christian-Albrechts-University of Kiel, 24098 Kiel, Germany
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22
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Claridge SA, Liao WS, Thomas JC, Zhao Y, Cao H, Cheunkar S, Serino AC, Andrews AM, Weiss PS. From the bottom up: dimensional control and characterization in molecular monolayers. Chem Soc Rev 2013; 42:2725-45. [PMID: 23258565 PMCID: PMC3596502 DOI: 10.1039/c2cs35365b] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Self-assembled monolayers are a unique class of nanostructured materials, with properties determined by their molecular lattice structures, as well as the interfaces with their substrates and environments. As with other nanostructured materials, defects and dimensionality play important roles in the physical, chemical, and biological properties of the monolayers. In this review, we discuss monolayer structures ranging from surfaces (two-dimensional) down to single molecules (zero-dimensional), with a focus on applications of each type of structure, and on techniques that enable characterization of monolayer physical properties down to the single-molecule scale.
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Affiliation(s)
- Shelley A. Claridge
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Wei-Ssu Liao
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - John C. Thomas
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Yuxi Zhao
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Huan Cao
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Sarawut Cheunkar
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Andrew C. Serino
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Anne M. Andrews
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Psychiatry, University of California, Los Angeles, Los Angeles, California 90095, United States
- Semel Institute for Neuroscience & Human Behavior, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Paul S. Weiss
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry & Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Materials Science & Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States
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23
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Affiliation(s)
- Bala Krishna Pathem
- California NanoSystems Institute,
- Department of Chemistry and Biochemistry, and
| | - Shelley A. Claridge
- California NanoSystems Institute,
- Department of Chemistry and Biochemistry, and
| | - Yue Bing Zheng
- California NanoSystems Institute,
- Department of Chemistry and Biochemistry, and
| | - Paul S. Weiss
- California NanoSystems Institute,
- Department of Chemistry and Biochemistry, and
- Department of Materials Science and Engineering, University of California, Los Angeles, California 90095;
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24
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Gahl C, Brete D, Leyssner F, Koch M, McNellis ER, Mielke J, Carley R, Grill L, Reuter K, Tegeder P, Weinelt M. Coverage- and Temperature-Controlled Isomerization of an Imine Derivative on Au(111). J Am Chem Soc 2013; 135:4273-81. [DOI: 10.1021/ja309330e] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Cornelius Gahl
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195
Berlin, Germany
| | - Daniel Brete
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195
Berlin, Germany
- Max-Born-Institut, Max-Born-Str. 2A, 12489 Berlin,
Germany
| | - Felix Leyssner
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195
Berlin, Germany
| | - Matthias Koch
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195
Berlin, Germany
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin,
Germany
| | - Erik R. McNellis
- Department of
Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg
10, 55128 Mainz, Germany
| | - Johannes Mielke
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin,
Germany
| | - Robert Carley
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195
Berlin, Germany
- Max-Born-Institut, Max-Born-Str. 2A, 12489 Berlin,
Germany
| | - Leonhard Grill
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin,
Germany
| | - Karsten Reuter
- Lehrstuhl für Theoretische
Chemie, Technische Universität München, Lichtenbergstr. 4, 85747 Garching, Germany
| | - Petra Tegeder
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195
Berlin, Germany
| | - Martin Weinelt
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195
Berlin, Germany
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25
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Petek H. Photoexcitation of adsorbates on metal surfaces: one-step or three-step. J Chem Phys 2013; 137:091704. [PMID: 22957546 DOI: 10.1063/1.4746801] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
In this essay we discuss the light-matter interactions at molecule-covered metal surfaces that initiate surface photochemistry. The hot-electron mechanism for surface photochemistry, whereby the absorption of light by a metal surface creates an electron-hole pair, and the hot electron scatters through an unoccupied resonance of adsorbate to initiate nuclear dynamics leading to photochemistry, has become widely accepted. Yet, ultrafast spectroscopic measurements of molecule-surface electronic structure and photoexcitation dynamics provide scant support for the hot electron mechanism. Instead, in most cases the adsorbate resonances are excited through photoinduced substrate-to-adsorbate charge transfer. Based on recent studies of the role of coherence in adsorbate photoexcitation, as measured by the optical phase and momentum resolved two-photon photoemission measurements, we examine critically the hot electron mechanism, and propose an alternative description based on direct charge transfer of electrons from the substrate to adsorbate. The advantage of this more quantum mechanically rigorous description is that it informs how material properties of the substrate and adsorbate, as well as their interaction, influence the frequency dependent probability of photoexcitation and ultimately how light can be used to probe and control surface femtochemistry.
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Affiliation(s)
- Hrvoje Petek
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
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26
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Huang T, Zhao J, Feng M, Popov AA, Yang S, Dunsch L, Petek H. A multi-state single-molecule switch actuated by rotation of an encapsulated cluster within a fullerene cage. Chem Phys Lett 2012. [DOI: 10.1016/j.cplett.2012.09.064] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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27
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Tegeder P. Optically and thermally induced molecular switching processes at metal surfaces. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:394001. [PMID: 22964773 DOI: 10.1088/0953-8984/24/39/394001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Using light to control the switching of functional properties of surface-bound species is an attractive strategy for the development of new technologies with possible applications in molecular electronics and functional surfaces and interfaces. Molecular switches are promising systems for such a route, since they possess the ability to undergo reversible changes between different molecular states and accordingly molecular properties by excitation with light or other external stimuli. In this review, recent experiments on photo- and thermally induced molecular switching processes at noble metal surfaces utilizing two-photon photoemission and surface vibrational spectroscopies are reported. The investigated molecular switches can either undergo a trans-cis isomerization or a ring opening-closure reaction. Two approaches concerning the connection of the switches to the surface are applied: physisorbed switches, i.e. molecules in direct contact with the substrate, and surface-decoupled switches incorporated in self-assembled monolayers. Elementary processes in molecular switches at surfaces, such as excitation mechanisms in photoisomerization and kinetic parameters for thermally driven reactions, which are essential for a microscopic understanding of molecular switching at surfaces, are presented. This in turn is needed for designing an appropriate adsorbate-substrate system with the desired switchable functionality controlled by external stimuli.
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Affiliation(s)
- Petra Tegeder
- Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, D-14195 Berlin, Germany.
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28
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Mielke J, Selvanathan S, Peters M, Schwarz J, Hecht S, Grill L. Molecules with multiple switching units on a Au(111) surface: self-organization and single-molecule manipulation. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:394013. [PMID: 22964491 DOI: 10.1088/0953-8984/24/39/394013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Three different molecules, each containing two azobenzene switching units, were synthesized, successfully deposited onto a Au(111) surface by sublimation and studied by scanning tunneling microscopy at low temperatures. To investigate the influence of electronic coupling between the switching units as well as to the surface, the two azo moieties were connected either via π-conjugated para-phenylene or decoupling meta-phenylene bridges, and the number of tert-butyl groups was varied in the meta-phenylene-linked derivatives. Single molecules were found to be intact after deposition as identified by their characteristic appearance in STM images. Due to their mobility on the Au(111) surface at room temperature, the molecules spontaneously formed self-organized molecular arrangements that reflected their chemical structure. While lateral displacement of the molecules was accomplished by manipulation, trans-cis isomerization processes, typical for azobenzene switches, could not be induced.
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Affiliation(s)
- Johannes Mielke
- Department of Physical Chemistry, Fritz-Haber-Institute of the Max-Planck-Society, D-14195 Berlin, Germany
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29
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Schulze G, Franke KJ, Pascual JI. Induction of a photostationary ring-opening-ring-closing state of spiropyran monolayers on the semimetallic Bi(110) surface. PHYSICAL REVIEW LETTERS 2012; 109:026102. [PMID: 23030183 DOI: 10.1103/physrevlett.109.026102] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Indexed: 05/22/2023]
Abstract
Molecular switches on metal surfaces typically show very little photoreactivity. Using scanning tunneling microscopy, we show that the ring-opening-ring-closing switch nitrospiropyran thermally and optically isomerizes to the open merocyanine form on a Bi(110) surface. Irradiation by blue light of a monolayer of spiropyran molecules leads to mixed domains of the two isomers. At large illumination intensities a photostationary state is established, indicating the bidirectional ring-opening and ring-closing reaction of these molecules on the bismuth surface. The enhanced photoactivity contrasts with the case of adsorption on other metal surfaces, probably due to the low density of states at the Fermi level of the semimetallic Bi(110) surface.
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Affiliation(s)
- Gunnar Schulze
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
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30
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García Rey N, Arnolds H. Hot hole-induced dissociation of NO dimers on a copper surface. J Chem Phys 2011; 135:224708. [DOI: 10.1063/1.3664861] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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31
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Maurer RJ, Reuter K. Assessing computationally efficient isomerization dynamics: ΔSCF density-functional theory study of azobenzene molecular switching. J Chem Phys 2011; 135:224303. [DOI: 10.1063/1.3664305] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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32
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Bronner C, Schulze G, Franke KJ, Pascual JI, Tegeder P. Switching ability of nitro-spiropyran on Au(111): electronic structure changes as a sensitive probe during a ring-opening reaction. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:484005. [PMID: 22085915 DOI: 10.1088/0953-8984/23/48/484005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Spiropyran is a prototype molecular switch which undergoes a reversible ring-opening reaction by photoinduced cleavage of a C-O bond in the spiropyran (SP) to the merocyanine (MC) isomer. While the electronic states and switching behavior are well characterized in solution, adsorption on metal surfaces crucially affects these properties. Using two-photon photoemission and scanning tunneling spectroscopy, we resolve the molecular energy levels on a Au(111) surface of both isomeric forms. Illumination at various wavelengths does not yield any observable switching rate, thus evidencing a very small upper limit of the quantum efficiency. Electron-induced switching from the SP to the MC isomer via generation of a negative ion resonance can be detected with a quantum yield of (2.2 ± 0.2) × 10(-10) events/electron in tunneling spectroscopy. In contrast, the back reaction could not be observed. This study reveals that the switching properties of surface-bound molecular switches can be very different compared with free molecules, reflecting the strong influence of the interaction with the metal substrate.
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33
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Mulugeta D, Watanabe K, Menzel D, Freund HJ. State-resolved investigation of the photodesorption dynamics of NO from (NO)2 on Ag nanoparticles of various sizes in comparison with Ag(111). J Chem Phys 2011; 134:164702. [DOI: 10.1063/1.3581802] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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34
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Heinemann N, Leissner T, Grunau J, Rohwer T, Andreyev O, Bauer M. Two-photon photoemission from ex-situ prepared butanethiol SAMs on Au (111). Chem Phys 2011. [DOI: 10.1016/j.chemphys.2011.03.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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35
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Mielke J, Leyssner F, Koch M, Meyer S, Luo Y, Selvanathan S, Haag R, Tegeder P, Grill L. Imine derivatives on Au(111): evidence for "inverted" thermal isomerization. ACS NANO 2011; 5:2090-2097. [PMID: 21332132 DOI: 10.1021/nn103297e] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Molecules that undergo reversible isomerization between trans and cis states, typically upon illumination with light at appropriate wavelengths, represent an important class of molecular switches. In this combined scanning tunneling microscopy (STM) and high-resolution electron energy loss spectroscopy (HREELS) study, we report on self-assembled arrays of imine derivatives on a Au(111) surface. Most of the molecules are found in the trans state after deposition at room temperature, but many of them change their conformation upon heating, which we assign to switching to the cis state. As for many molecular switches, the trans isomer is the energetically more stable compound in solution, resulting in thermal cis to trans relaxation upon sufficient heating. On the surface, however, the number of cis isomers increases with temperature, pointing toward an "inverted" thermal isomerization behavior. The reason for this surface-mediated effect could be a stronger coupling, as compared to the trans state, of the central imine part of the molecule to the gold surface, which is sterically only possible in the cis state.
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Affiliation(s)
- Johannes Mielke
- Physics Department, Freie Universität Berlin, Arnimallee 14, Berlin, Germany
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36
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Bazarnik M, Henzl J, Czajka R, Morgenstern K. Light driven reactions of single physisorbed azobenzenes. Chem Commun (Camb) 2011; 47:7764-6. [DOI: 10.1039/c1cc11578b] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Bulky spacer groups – A valid strategy to control the coupling of functional molecules to surfaces? Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2010.09.051] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Óvári L, Luo Y, Leyssner F, Haag R, Wolf M, Tegeder P. Adsorption and switching properties of a N-benzylideneaniline based molecular switch on a Au(111) surface. J Chem Phys 2010; 133:044707. [DOI: 10.1063/1.3460647] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Safiei A, Henzl J, Morgenstern K. Isomerization of an azobenzene derivative on a thin insulating layer by inelastically tunneling electrons. PHYSICAL REVIEW LETTERS 2010; 104:216102. [PMID: 20867119 DOI: 10.1103/physrevlett.104.216102] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Indexed: 05/29/2023]
Abstract
Scanning tunneling microscopy is used to investigate isomerization of amino-nitro-azobenzene on a thin NaCl layer on Ag(111) by inelastically tunneling electrons. A reversible isomerization between a planar trans and a three-dimensional cis form with two different thresholds is demonstrated. The isomerization characteristics are rationalized in terms of binding of the multipolar molecule to the ionic layer. This study shows the feasibility of a bistable single molecule switch on an insulator.
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Affiliation(s)
- Ali Safiei
- Institut für Festkörperphysik, Abteilung ATMOS, Leibniz Universität Hannover, Appelstrasse 2, D-30167 Hannover, Germany
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Gahl C, Schmidt R, Brete D, McNellis ER, Freyer W, Carley R, Reuter K, Weinelt M. Structure and excitonic coupling in self-assembled monolayers of azobenzene-functionalized alkanethiols. J Am Chem Soc 2010; 132:1831-8. [PMID: 20099853 DOI: 10.1021/ja903636q] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Optical properties and the geometric structure of self-assembled monolayers of azobenzene-functionalized alkanethiols have been investigated by UV/visible and near edge X-ray absorption fine structure spectroscopy in combination with density-functional theory. By attaching a trifluoro-methyl end group to the chromophore both the molecular tilt and twist angle of the azobenzene moiety are accessible. Based on this detailed structural analysis the energetic shifts observed in optical reflection spectroscopy can be qualitatively described within an extended dipole model. This substantiates sizable excitonic coupling among the azobenzene chromophores as an important mechanism that hinders trans to cis isomerization in densely packed self-assembled monolayers.
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Affiliation(s)
- Cornelius Gahl
- Max-Born-Institut, Max-Born-Str. 2A, 12489 Berlin, Germany.
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Henzl J, Morgenstern K. An electron induced two-dimensional switch made of azobenzene derivatives anchored in supramolecular assemblies. Phys Chem Chem Phys 2010; 12:6035-44. [PMID: 20386802 DOI: 10.1039/b924488c] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Supramolecular assemblies of 4-anilino-4'-nitroazobenzene are investigated on the Au(111) surface by low temperature scanning tunneling microscopy and spectroscopy with submolecular resolution. Adsorption at 250 K leads to three different structures that are formed via hydrogen bonds: a star structure and two types of line structures: a meandering and a zigzag line. The formation of these supramolecular assemblies is affected by the available space on the fcc domains of the reconstructed Au(111) substrate as well as by the two-dimensional chirality of the molecules on the surface. The star structure is enantiomerically pure, while both types of lines consist of a racemic mixture. Bonding between homochiral pairs differ from the one between heterochiral pairs in the position of the hydrogen bonds. Inside these supramolecular assemblies two configurations of the molecules are identified: An almost straight trans-configuration and a slightly bent cis*-configuration. The trans-configuration largely reflects the structure of this isomer in gas phase, while the cis*-configuration is two-dimensional on the surface in contrast to the three-dimensional gas phase cis-configuration. The reversible trans-cis* isomerization is induced by electron tunneling through the LUMO+1 state of the molecule, which is located at +2.9 V.
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Affiliation(s)
- Jörg Henzl
- Leibniz Universität Hannover, Institut für Festkörperphysik, Abteilung für atomare und molekulare Strukturen (ATMOS), Appelstr. 2, D-30167 Hannover, Germany.
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Schmidt R, Hagen S, Brete D, Carley R, Gahl C, Dokić J, Saalfrank P, Hecht S, Tegeder P, Weinelt M. On the electronic and geometrical structure of the trans- and cis-isomer of tetra-tert-butyl-azobenzene on Au(111). Phys Chem Chem Phys 2010; 12:4488-97. [DOI: 10.1039/b924409c] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Schönborn JB, Herges R, Hartke B. Brownian molecular rotors: Theoretical design principles and predicted realizations. J Chem Phys 2009; 130:234906. [DOI: 10.1063/1.3148223] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Wagner S, Leyssner F, Kördel C, Zarwell S, Schmidt R, Weinelt M, Rück-Braun K, Wolf M, Tegeder P. Reversible photoisomerization of an azobenzene-functionalized self-assembled monolayer probed by sum-frequency generation vibrational spectroscopy. Phys Chem Chem Phys 2009; 11:6242-8. [DOI: 10.1039/b823330f] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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