1
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Li P, Bera S, Kumar-Saxena S, Pecht I, Sheves M, Cahen D, Selzer Y. Electron transport through two interacting channels in Azurin-based solid-state junctions. Proc Natl Acad Sci U S A 2024; 121:e2405156121. [PMID: 39110736 PMCID: PMC11331140 DOI: 10.1073/pnas.2405156121] [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: 03/14/2024] [Accepted: 07/12/2024] [Indexed: 08/21/2024] Open
Abstract
The fundamental question of "what is the transport path of electrons through proteins?" initially introduced while studying long-range electron transfer between localized redox centers in proteins in vivo is also highly relevant to the transport properties of solid-state, dry metal-protein-metal junctions. Here, we report conductance measurements of such junctions, Au-(Azurin monolayer ensemble)-Bismuth (Bi) ones, with well-defined nanopore geometry and ~103 proteins/pore. Our results can be understood as follows. (1) Transport is via two interacting conducting channels, characterized by different spatial and time scales. The slow and spatially localized channel is associated with the Cu center of Azurin and the fast delocalized one with the protein's polypeptide matrix. Transport via the slow channel is by a sequential (noncoherent) process and in the second one by direct, off-resonant tunneling. (2) The two channels are capacitively coupled. Thus, with a change in charge occupation of the weakly coupled (metal center) channel, the broad energy level manifold, responsible for off-resonance tunneling, shifts, relative to the electrodes' Fermi levels. In this process, the off-resonance (fast) channel dominates transport, and the slow (redox) channel, while contributing only negligibly directly, significantly affects transport by intramolecular gating.
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Affiliation(s)
- Ping’an Li
- Department of Chemical Physics, School of Chemistry, Tel Aviv University, Tel Aviv69978, Israel
| | - Sudipta Bera
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot76100, Israel
| | - Shailendra Kumar-Saxena
- Department of Physics and Nanotechnology, College of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur603203, Tamil Nadu, India
| | - Israel Pecht
- Department of Regenerative Biology and Immunology, Weizmann Institute of Science, Rehovot76100, Israel
| | - Mordechai Sheves
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot76100, Israel
| | - David Cahen
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot76100, Israel
| | - Yoram Selzer
- Department of Chemical Physics, School of Chemistry, Tel Aviv University, Tel Aviv69978, Israel
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2
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Chen Z, Woltering SL, Limburg B, Tsang MY, Baugh J, Briggs GAD, Mol JA, Anderson HL, Thomas JO. Connections to the Electrodes Control the Transport Mechanism in Single-Molecule Transistors. Angew Chem Int Ed Engl 2024; 63:e202401323. [PMID: 38410064 DOI: 10.1002/anie.202401323] [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: 01/19/2024] [Revised: 02/23/2024] [Accepted: 02/26/2024] [Indexed: 02/28/2024]
Abstract
When designing a molecular electronic device for a specific function, it is necessary to control whether the charge-transport mechanism is phase-coherent transmission or particle-like hopping. Here we report a systematic study of charge transport through single zinc-porphyrin molecules embedded in graphene nanogaps to form transistors, and show that the transport mechanism depends on the chemistry of the molecule-electrode interfaces. We show that van der Waals interactions between molecular anchoring groups and graphene yield transport characteristic of Coulomb blockade with incoherent sequential hopping, whereas covalent molecule-electrode amide bonds give intermediately or strongly coupled single-molecule devices that display coherent transmission. These findings demonstrate the importance of interfacial engineering in molecular electronic circuits.
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Affiliation(s)
- Zhixin Chen
- Department of Materials, University of Oxford, 16 Parks Road, Oxford, OX1 3PH, UK
| | - Steffen L Woltering
- Department of Materials, University of Oxford, 16 Parks Road, Oxford, OX1 3PH, UK
- Department of Chemistry, University of Oxford Chemistry Research Laboratory, Oxford, OX1 3TA, UK
| | - Bart Limburg
- Department of Chemistry, University of Oxford Chemistry Research Laboratory, Oxford, OX1 3TA, UK
| | - Ming-Yee Tsang
- Department of Materials, University of Oxford, 16 Parks Road, Oxford, OX1 3PH, UK
| | - Jonathan Baugh
- Institute for Quantum Computing, University of Waterloo, 200 University Avenue West, N2 L 3G1, Waterloo, ON, Canada
| | - G Andrew D Briggs
- Department of Materials, University of Oxford, 16 Parks Road, Oxford, OX1 3PH, UK
| | - Jan A Mol
- School of Physical and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Harry L Anderson
- Department of Chemistry, University of Oxford Chemistry Research Laboratory, Oxford, OX1 3TA, UK
| | - James O Thomas
- Department of Materials, University of Oxford, 16 Parks Road, Oxford, OX1 3PH, UK
- School of Physical and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
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3
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Meng Q, Zhang J, Zhang Y, Chu W, Mao W, Zhang Y, Yang J, Luo Y, Dong Z, Hou JG. Local heating and Raman thermometry in a single molecule. SCIENCE ADVANCES 2024; 10:eadl1015. [PMID: 38232173 DOI: 10.1126/sciadv.adl1015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 12/15/2023] [Indexed: 01/19/2024]
Abstract
Because of the nonequilibrium nature of thermal effects at the nanoscale, the characterization of local thermal effects within a single molecule is highly challenging. Here, we demonstrate a way to characterize the local thermal properties of a single fullerene (C60) molecule during current-induced heating processes through tip-enhanced anti-Stokes Raman spectroscopy. Although the measured vibron populations are far from equilibrium with the environment, we can still define an "effective temperature (Teff)" statistically via a Bose-Einstein distribution, suggesting a local equilibrium within the molecule. With increased current heating, Teff is found to rise up to about 1150 K until the C60 cage is decomposed. Such a decomposition temperature is similar to that reported for ensemble C60 samples, thus justifying the validity of our methodology. Moreover, the possible reaction pathway and product can be identified because of the chemical sensitivity of Raman spectroscopy. Our findings provide a practical method for noninvasively detecting the local heating effect inside a single molecule under nonequilibrium conditions.
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Affiliation(s)
- Qiushi Meng
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Junxian Zhang
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Yao Zhang
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
- School of Physics and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Weizhe Chu
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Wenjie Mao
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Yang Zhang
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
- School of Physics and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Jinlong Yang
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
- School of Physics and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Yi Luo
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
- School of Physics and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Zhenchao Dong
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
- School of Physics and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - J G Hou
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
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4
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Erpenbeck A, Ke Y, Peskin U, Thoss M. How an electrical current can stabilize a molecular nanojunction. NANOSCALE 2023; 15:16333-16343. [PMID: 37766513 DOI: 10.1039/d3nr02176a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/29/2023]
Abstract
The stability of molecular junctions under transport is of the utmost importance for the field of molecular electronics. This question is often addressed within the paradigm of current-induced heating of nuclear degrees of freedom or current-induced forces acting upon the nuclei. At the same time, an essential characteristic of the failure of a molecular electronic device is its changing conductance - typically from a finite value for the intact device to zero for a device that lost its functionality. In this publication, we focus on the current-induced changes in the molecular conductance, which are inherent to molecular junctions at the limit of mechanical stability. We employ a numerically exact framework based on the hierarchical equations of motion approach, which treats both electronic and nuclear degrees of freedom on an equal footing and does not impose additional assumptions. Studying generic model systems for molecular junctions with dissociative potentials for a wide range of parameters spanning the adiabatic and the nonadiabatic regime, we find that molecular junctions that exhibit a decrease in conductance upon dissociation are more stable than junctions that are more conducting in their dissociated state. This represents a new mechanism that stabilizes molecular junctions under current. Moreover, we identify characteristic signatures in the current of breaking junctions related to the interplay between changes in the conductance and the nuclear configuration and show how these are related to properties of the leads rather than characteristics of the molecule itself.
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Affiliation(s)
- André Erpenbeck
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA.
| | - Yaling Ke
- Institute of Physics, University of Freiburg, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
| | - Uri Peskin
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Michael Thoss
- Institute of Physics, University of Freiburg, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
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5
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Bian X, Chen Z, Sowa JK, Evangeli C, Limburg B, Swett JL, Baugh J, Briggs GAD, Anderson HL, Mol JA, Thomas JO. Charge-State Dependent Vibrational Relaxation in a Single-Molecule Junction. PHYSICAL REVIEW LETTERS 2022; 129:207702. [PMID: 36462006 DOI: 10.1103/physrevlett.129.207702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 10/20/2022] [Indexed: 06/17/2023]
Abstract
The outcome of an electron-transfer process is determined by the quantum-mechanical interplay between electronic and vibrational degrees of freedom. Nonequilibrium vibrational dynamics are known to direct electron-transfer mechanisms in molecular systems; however, the structural features of a molecule that lead to certain modes being pushed out of equilibrium are not well understood. Herein, we report on electron transport through a porphyrin dimer molecule, weakly coupled to graphene electrodes, that displays sequential tunneling within the Coulomb-blockade regime. The sequential transport is initiated by current-induced phonon absorption and proceeds by rapid sequential transport via a nonequilibrium vibrational distribution of low-energy modes, likely related to torsional molecular motions. We demonstrate that this is an experimental signature of slow vibrational dissipation, and obtain a lower bound for the vibrational relaxation time of 8 ns, a value dependent on the molecular charge state.
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Affiliation(s)
- Xinya Bian
- Department of Materials, University of Oxford, Oxford OX1 3PH, United Kingdom
| | - Zhixin Chen
- Department of Materials, University of Oxford, Oxford OX1 3PH, United Kingdom
| | - Jakub K Sowa
- Department of Chemistry, Rice University, Houston, Texas 77005, USA
| | | | - Bart Limburg
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Jacob L Swett
- Department of Materials, University of Oxford, Oxford OX1 3PH, United Kingdom
| | - Jonathan Baugh
- Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - G Andrew D Briggs
- Department of Materials, University of Oxford, Oxford OX1 3PH, United Kingdom
| | - Harry L Anderson
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Jan A Mol
- School of Physical and Chemical Sciences, Queen Mary University, London E1 4NS, United Kingdom
| | - James O Thomas
- Department of Materials, University of Oxford, Oxford OX1 3PH, United Kingdom
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6
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Liu Z, Hu T, Adam Balila MO, Zhang J, Zhang Y, Hu W. Investigation of SERS and Electron Transport Properties of Oligomer Phenylacetyne-3 Trapped in Gold Junctions. NANOMATERIALS 2022; 12:nano12030571. [PMID: 35159916 PMCID: PMC8839768 DOI: 10.3390/nano12030571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/27/2022] [Accepted: 01/29/2022] [Indexed: 12/04/2022]
Abstract
Molecular junctions hold great potential for future microelectronics and attract people’s attention. Here, we used density functional theory calculations (DFT) to investigate the surface-enhanced Raman spectroscopy (SERS) and electron transport properties of fully π-conjugated oligomers (phenylacetylene)-3 (OPE-3) trapped in gold junctions. The effects of charge injection, an applied electric field, and molecular deformation are considered. We found that a new Raman peak located at around 1400 cm−1 appears after the injection of a charge, which agrees well with the experiment. The external electric field and configurational deformation hardly affect the Raman spectra, indicating that the electronic rather than the geometrical structure determines the Raman response. Nonequilibrium Green’s function (NEGF) calculations show that both the rotation of the benzene groups and an increased electrode distance largely reduced the conductivity of the studied molecular junctions. The present investigations provide valuable information on the effect of charging, electric field, and deformation on the SERS and conductivity of molecular junctions, helping the development of molecular devices.
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Affiliation(s)
- Ziyu Liu
- School of Chemistry and Chemical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China; (Z.L.); (T.H.); (M.O.A.B.)
| | - Tingting Hu
- School of Chemistry and Chemical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China; (Z.L.); (T.H.); (M.O.A.B.)
- Technology College of Chemical Engineering, Qingdao University of Science, Qingdao 266061, China
| | - Muwafag Osman Adam Balila
- School of Chemistry and Chemical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China; (Z.L.); (T.H.); (M.O.A.B.)
| | - Jihui Zhang
- School of Materials Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China;
| | - Yujin Zhang
- School of Electronic and Information Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China
- Correspondence: (Y.Z.); (W.H.)
| | - Wei Hu
- School of Chemistry and Chemical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China; (Z.L.); (T.H.); (M.O.A.B.)
- Correspondence: (Y.Z.); (W.H.)
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7
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Zhang L, Jin T, Guo Y, Martin AC, Sun K, Dudley GB, Yang J. Synthesis of gem-Dimethylcyclopentane-Fused Arenes with Various Topologies via TBD-Mediated Dehydro-Diels-Alder Reaction. J Org Chem 2021; 86:16716-16724. [PMID: 34709035 DOI: 10.1021/acs.joc.1c01957] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The development of efficient methods for the synthesis of substituted polycyclic arenes with various topologies is in high demand due to their excellent electrical and optical properties. In this work, a series of gem-dimethylcyclopentane-fused arenes with more than ten topologies were synthesized via a 1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD)-mediated dehydro-Diels-Alder reaction with moderate to good yields. The introduction of the near-planar gem-dimethylcyclopentane moiety not only impacts the molecular conjugative system but also regulates the intermolecular π-π interactions and crystal packing, which are critical for the photoelectric performance of arenes. The photophysical properties, molecular geometry, molecular packing of these compounds, and electrochemical properties were investigated by UV-vis absorption, fluorescence emission spectra, DFT calculations, single-crystal X-ray structure analysis, and cyclic voltammetry study.
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Affiliation(s)
- Liyan Zhang
- State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, 438West Hebei Street, Qinhuangdao 066004, P. R. China.,Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineering, Yanshan University, 438 West Hebei Street, Qinhuangdao 066004, P. R. China
| | - Tengda Jin
- State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, 438West Hebei Street, Qinhuangdao 066004, P. R. China.,Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineering, Yanshan University, 438 West Hebei Street, Qinhuangdao 066004, P. R. China
| | - Yingjie Guo
- State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, 438West Hebei Street, Qinhuangdao 066004, P. R. China.,Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineering, Yanshan University, 438 West Hebei Street, Qinhuangdao 066004, P. R. China
| | - A C Martin
- Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Keju Sun
- State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, 438West Hebei Street, Qinhuangdao 066004, P. R. China.,Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineering, Yanshan University, 438 West Hebei Street, Qinhuangdao 066004, P. R. China
| | - Gregory B Dudley
- Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Jingyue Yang
- State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, 438West Hebei Street, Qinhuangdao 066004, P. R. China.,Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineering, Yanshan University, 438 West Hebei Street, Qinhuangdao 066004, P. R. China
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8
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Bi H, Jing C, Hasch P, Gong Y, Gerster D, Barth JV, Reichert J. Single Molecules in Strong Optical Fields: A Variable-Temperature Molecular Junction Spectroscopy Setup. Anal Chem 2021; 93:9853-9859. [PMID: 34229433 DOI: 10.1021/acs.analchem.1c01633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In order to advance the development of molecular electronic devices, it is mandatory to improve the understanding of electron transport and functionalities in single molecules, integrated in a well-defined environment. However, limited information can be obtained by solely analyzing I-V characteristics, whence multiparameter studies are required to obtain more information on such systems including chemical bonds, geometry, and intramolecular strain. Therefore, we developed an analytical method incorporating an optical near-field technique, which allows us to investigate single-molecule junctions at variable temperatures in strong optical fields. An apertureless near-field emitter acts as a counter electrode and a plasmonic waveguide to focus surface plasmon polaritons into the molecular junctions, where a strongly enhanced evanescent field is confined to only a few nanometers around the apex of the tip. The proof of concept, even at low temperatures, is demonstrated by simultaneously investigating electronic and optical features of the molecule p-terphenyl-4,4″-dithiol in dependence of its charge state. This multichannel method can be employed to analyze a variety of nearly unexplored properties in single-molecule junctions such as photoconductance and photocurrent generation and allows a characterization of the molecular junctions by spectroscopic means as well.
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Affiliation(s)
- Hai Bi
- Physics-Department E20, Technical University of Munich, James Franck Str. 1, 85748 Garching, Germany
| | - Chao Jing
- Physics-Department E20, Technical University of Munich, James Franck Str. 1, 85748 Garching, Germany.,Department of Hydrogen Technique, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Jialuo Road 2019, 201800 Shanghai, China.,School of Chemistry & Molecular Engineering, East China University of Science and Technology, Meilong Road 130, 200237 Shanghai, China
| | - Peter Hasch
- Physics-Department E20, Technical University of Munich, James Franck Str. 1, 85748 Garching, Germany
| | - Yuxiang Gong
- Physics-Department E20, Technical University of Munich, James Franck Str. 1, 85748 Garching, Germany
| | - Daniel Gerster
- Physics-Department E20, Technical University of Munich, James Franck Str. 1, 85748 Garching, Germany
| | - Johannes V Barth
- Physics-Department E20, Technical University of Munich, James Franck Str. 1, 85748 Garching, Germany
| | - Joachim Reichert
- Physics-Department E20, Technical University of Munich, James Franck Str. 1, 85748 Garching, Germany
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9
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Ma J, Cheng Y, Sun M. Plexcitons, electric field gradient and electron-phonon coupling in tip-enhanced Raman spectroscopy (TERS). NANOSCALE 2021; 13:10712-10725. [PMID: 34128524 DOI: 10.1039/d1nr02205a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Tip-Enhanced Raman Spectroscopy (TERS) provides very high spatial resolution and detection sensitivity, so it has important applications in nano-scale molecular analysis. Plexciton is a polarization mode caused by a strongly coupled interaction between plasma excitons and excitons. It is a hot topic in plasma photonics research. We introduce the characteristics, production methods, observation methods and some applications of TERS. The electric field gradient (EFG) is an important factor affecting TERS resolution. The electron-phonon interaction is a fundamental inelastic interaction and plays an important role in current-carrying single-molecular junctions. This article summarizes the characteristics and applications of these three parts for readers to gain a preliminary understanding.
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Affiliation(s)
- Jialin Ma
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, People's Republic of China.
| | - Yuqing Cheng
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, People's Republic of China.
| | - Mengtao Sun
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, People's Republic of China. and Collaborative Innovation Center of Light Manipulations and Applications, Shandong Normal University, Jinan 250358, P. R. China
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10
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Ke Y, Erpenbeck A, Peskin U, Thoss M. Unraveling current-induced dissociation mechanisms in single-molecule junctions. J Chem Phys 2021; 154:234702. [PMID: 34241274 DOI: 10.1063/5.0053828] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Understanding current-induced bond rupture in single-molecule junctions is both of fundamental interest and a prerequisite for the design of molecular junctions, which are stable at higher-bias voltages. In this work, we use a fully quantum mechanical method based on the hierarchical quantum master equation approach to analyze the dissociation mechanisms in molecular junctions. Considering a wide range of transport regimes, from off-resonant to resonant, non-adiabatic to adiabatic transport, and weak to strong vibronic coupling, our systematic study identifies three dissociation mechanisms. In the weak and intermediate vibronic coupling regime, the dominant dissociation mechanism is stepwise vibrational ladder climbing. For strong vibronic coupling, dissociation is induced via multi-quantum vibrational excitations triggered either by a single electronic transition at high bias voltages or by multiple electronic transitions at low biases. Furthermore, the influence of vibrational relaxation on the dissociation dynamics is analyzed and strategies for improving the stability of molecular junctions are discussed.
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Affiliation(s)
- Yaling Ke
- Institute of Physics, Albert-Ludwig University Freiburg, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
| | - André Erpenbeck
- School of Chemistry, The Raymond and Beverley Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Uri Peskin
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Michael Thoss
- Institute of Physics, Albert-Ludwig University Freiburg, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
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11
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Han Y, Nijhuis CA. Functional Redox-Active Molecular Tunnel Junctions. Chem Asian J 2020; 15:3752-3770. [PMID: 33015998 PMCID: PMC7756406 DOI: 10.1002/asia.202000932] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/29/2020] [Indexed: 01/10/2023]
Abstract
Redox-active molecular junctions have attracted considerable attention because redox-active molecules provide accessible energy levels enabling electronic function at the molecular length scales, such as, rectification, conductance switching, or molecular transistors. Unlike charge transfer in wet electrochemical environments, it is still challenging to understand how redox-processes proceed in solid-state molecular junctions which lack counterions and solvent molecules to stabilize the charge on the molecules. In this minireview, we first introduce molecular junctions based on redox-active molecules and discuss their properties from both a chemistry and nanoelectronics point of view, and then discuss briefly the mechanisms of charge transport in solid-state redox-junctions followed by examples where redox-molecules generate new electronic function. We conclude with challenges that need to be addressed and interesting future directions from a chemical engineering and molecular design perspectives.
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Affiliation(s)
- Yingmei Han
- Department of ChemistryNational University of Singapore3 Science Drive 3Singapore117543Singapore
| | - Christian A. Nijhuis
- Department of ChemistryNational University of Singapore3 Science Drive 3Singapore117543Singapore
- Centre for Advanced 2D Materials and Graphene Research CentreNational University of Singapore6 Science Drive 2Singapore117546Singapore
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12
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Meindl B, Pfennigbauer K, Stöger B, Heeney M, Glöcklhofer F. Double Ring-Closing Approach for the Synthesis of 2,3,6,7-Substituted Anthracene Derivatives. J Org Chem 2020; 85:8240-8244. [PMID: 32447951 DOI: 10.1021/acs.joc.0c00826] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A method for the synthesis of 2,3,6,7-substituted anthracene derivatives, one of the most challenging anthracene substitution patterns to obtain, is presented. The method is exemplified by the preparation of 2,3,6,7-anthracenetetracarbonitrile and employs a newly developed, stable, protected 1,2,4,5-benzenetetracarbaldehyde as the precursor. The precursor can be obtained in two scalable synthetic steps from 2,5-dibromoterephthalaldehyde and is converted into the anthracene derivative by a double intermolecular Wittig reaction under very mild conditions, followed by a deprotection and intramolecular double ring-closing condensation reaction.
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Affiliation(s)
- Birgit Meindl
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/163, Vienna 1060, Austria
| | - Katharina Pfennigbauer
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, Molecular Sciences Research Hub, 80 Wood Lane, London W12 0BZ, United Kingdom
| | - Berthold Stöger
- X-Ray Center, TU Wien, Getreidemarkt 9, Vienna 1060, Austria
| | - Martin Heeney
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, Molecular Sciences Research Hub, 80 Wood Lane, London W12 0BZ, United Kingdom
| | - Florian Glöcklhofer
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, Molecular Sciences Research Hub, 80 Wood Lane, London W12 0BZ, United Kingdom
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