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Lv X, Li C, Guo MM, Hong W, Chen LC, Zhang QC, Chen ZN. Hydroxyl Group as the 'Bridge' to Enhance the Single-Molecule Conductance by Hyperconjugation. Molecules 2024; 29:2440. [PMID: 38893316 PMCID: PMC11173964 DOI: 10.3390/molecules29112440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 05/17/2024] [Accepted: 05/20/2024] [Indexed: 06/21/2024] Open
Abstract
For designing single-molecule devices that have both conjugation systems and structural flexibility, a hyperconjugated molecule with a σ-π bond interaction is considered an ideal candidate. In the investigation of conductance at the single-molecule level, since few hyperconjugation systems have been involved, the strategy of building hyperconjugation systems and the mechanism of electron transport within this system remain unexplored. Based on the skipped-conjugated structure, we present a rational approach to construct a hyperconjugation molecule using a hydroxyl group, which serves as a bridge to interact with the conjugated fragments. The measurement of single-molecule conductance reveals a two-fold conductance enhancement of the hyperconjugation system having the 'bridging' hydroxyl group compared to hydroxyl-free derivatives. Theoretical studies demonstrate that the hydroxyl group in the hyperconjugation system connects the LUMO of the two conjugated fragments and opens a through-space channel for electron transport to enhance the conductance.
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Affiliation(s)
- Xin Lv
- Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (X.L.); (C.L.); (M.-M.G.); (Z.-N.C.)
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou 350007, China
- Fujian College, University of Chinese Academy of Sciences, Fuzhou 350002, China
| | - Chang Li
- Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (X.L.); (C.L.); (M.-M.G.); (Z.-N.C.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Meng-Meng Guo
- Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (X.L.); (C.L.); (M.-M.G.); (Z.-N.C.)
| | - Wenjing Hong
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China;
| | - Li-Chuan Chen
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China;
| | - Qian-Chong Zhang
- Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (X.L.); (C.L.); (M.-M.G.); (Z.-N.C.)
- Fujian College, University of Chinese Academy of Sciences, Fuzhou 350002, China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou 350108, China
| | - Zhong-Ning Chen
- Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (X.L.); (C.L.); (M.-M.G.); (Z.-N.C.)
- Fujian College, University of Chinese Academy of Sciences, Fuzhou 350002, China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou 350108, China
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2
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Bâldea I. Gaining insight into molecular tunnel junctions with a pocket calculator without I- V data fitting. Five-thirds protocol. Phys Chem Chem Phys 2024; 26:8724-8733. [PMID: 38416189 DOI: 10.1039/d4cp00217b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
The protocol put forward in the present paper is an attempt to meet the experimentalists' legitimate desire of reliably and easily extracting microscopic parameters from current-voltage measurements on molecular junctions. It applies to junctions wherein charge transport dominated by a single level (molecular orbital, MO) occurs via off-resonant tunneling. The recipe is simple. The measured current-voltage curve I = I(V) should be recast as a curve of V5/3/I versus V. This curve exhibits two maxima: one at positive bias (V = Vp+), another at negative bias (V = Vp-). The values Vp+ > 0 and Vp- < 0 at the two peaks of the curve for V5/3/I at positive and negative bias and the corresponding values Ip+ = I(Vp+) > 0 and Ip- = I(Vp-) < 0 of the current is all information needed as input. The arithmetic average of Vp+ and |Vp-| in volt provides the value in electronvolt of the MO energy offset ε0 = EMO - EF relative to the electrode Fermi level (|ε0| = e(Vp+ + |Vp-|)/2). The value of the (Stark) strength of the bias-driven MO shift is obtained as γ = (4/5)(Vp+ - |Vp-|)/(Vp+ + |Vp-|) sign (ε0). Even the low-bias conductance estimate, G = (3/8)(Ip+/Vp+ + Ip-/Vp-), can be a preferable alternative to that deduced from fitting the I-V slope in situations of noisy curves at low bias. To demonstrate the reliability and the generality of this "five-thirds" protocol, I illustrate its wide applicability for molecular tunnel junctions fabricated using metallic and nonmetallic electrodes, molecular species possessing localized σ and delocalized π electrons, and various techniques (mechanically controlled break junctions, STM break junctions, conducting probe AFM junctions, and large area junctions).
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Affiliation(s)
- Ioan Bâldea
- Theoretical Chemistry, Heidelberg University, Im Neuenheimer Feld 229, D-69120 Heidelberg, Germany.
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3
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Bâldea I. Dichotomy between Level Broadening and Level Coupling to Electrodes in Large Area EGaIn Molecular Junctions. J Phys Chem Lett 2024:2916-2921. [PMID: 38451082 DOI: 10.1021/acs.jpclett.4c00386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
Choosing self-assembled monolayers (SAMs) of fluorine-terminated oligophenylenes adsorbed on gold as an illustration, we show that a single-level [molecular orbital (MO)] model can excellently reproduce full I-V curves measured for large area junctions fabricated with a top EGaIn contact. In addition, this model unravels a surprising dichotomy between MO coupling to electrodes and MO broadening. Importantly for the coherence of the microscopic description, the latter is found to correlate with the SAM coverage and molecular and π* orbital tilt angles.
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Affiliation(s)
- Ioan Bâldea
- Theoretical Chemistry, Heidelberg University, Im Neuenheimer Feld 229, D-69120 Heidelberg, Germany
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4
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Prindle CR, Shi W, Li L, Dahl Jensen J, Laursen BW, Steigerwald ML, Nuckolls C, Venkataraman L. Effective Gating in Single-Molecule Junctions through Fano Resonances. J Am Chem Soc 2024; 146:3646-3650. [PMID: 38293735 DOI: 10.1021/jacs.3c14226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
The successful incorporation of molecules as active circuit elements relies on the ability to tune their electronic properties through chemical design. A synthetic strategy that has been used to manipulate and gate circuit conductance involves attaching a pendant substituent along the molecular conduction pathway. However, such a chemical gate has not yet been shown to significantly modify conductance. Here, we report a novel series of triarylmethylium and triangulenium carbocations gated by different substituents coupled to the delocalized conducting orbitals on the molecular backbone through a Fano resonance. By changing the pendant substituents to modulate the position of the Fano resonance and its coupling to the conducting orbitals, we can regulate the junction conductance by a remarkable factor of 450. This work thus provides a new design principle to enable effective chemical gating of single-molecule devices toward effective molecular transistors.
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Affiliation(s)
- Claudia R Prindle
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Wanzhuo Shi
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Liang Li
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Jesper Dahl Jensen
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Bo W Laursen
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Michael L Steigerwald
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Colin Nuckolls
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Latha Venkataraman
- Department of Chemistry, Columbia University, New York, New York 10027, United States
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, United States
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5
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Jago D, Liu C, Daaoub AHS, Gaschk E, Walkey MC, Pulbrook T, Qiao X, Sobolev AN, Moggach SA, Costa-Milan D, Higgins SJ, Piggott MJ, Sadeghi H, Nichols RJ, Sangtarash S, Vezzoli A, Koutsantonis GA. An Orthogonal Conductance Pathway in Spiropyrans for Well-Defined Electrosteric Switching Single-Molecule Junctions. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2306334. [PMID: 37817372 DOI: 10.1002/smll.202306334] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Indexed: 10/12/2023]
Abstract
While a multitude of studies have appeared touting the use of molecules as electronic components, the design of molecular switches is crucial for the next steps in molecular electronics. In this work, single-molecule devices incorporating spiropyrans, made using break junction techniques, are described. Linear spiropyrans with electrode-contacting groups linked by alkynyl spacers to both the indoline and chromenone moieties have previously provided very low conductance values, and removing the alkynyl spacer has resulted in a total loss of conductance. An orthogonal T-shaped approach to single-molecule junctions incorporating spiropyran moieties in which the conducting pathway lies orthogonal to the molecule backbone is described and characterized. This approach has provided singlemolecule conductance features with good correlation to molecular length. Additional higher conducting states are accessible using switching induced by UV light or protonation. Theoretical modeling demonstrates that upon (photo)chemical isomerization to the merocyanine, two cooperating phenomena increase conductance: release of steric hindrance allows the conductance pathway to become more planar (raising the mid-bandgap transmission) and a bound state introduces sharp interference near the Fermi level of the electrodes similarly responding to the change in state. This design step paves the way for future use of spiropyrans in single-molecule devices and electrosteric switches.
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Affiliation(s)
- David Jago
- School of Molecular Science, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - Chongguang Liu
- Department of Chemistry, University of Liverpool, Crown St, Liverpool, L69 7ZD, UK
| | | | - Emma Gaschk
- School of Molecular Science, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - Mark C Walkey
- School of Molecular Science, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - Thea Pulbrook
- School of Molecular Science, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - Xiaohang Qiao
- Department of Chemistry, University of Liverpool, Crown St, Liverpool, L69 7ZD, UK
| | - Alexandre N Sobolev
- Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - Stephen A Moggach
- School of Molecular Science, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - David Costa-Milan
- Department of Chemistry, University of Liverpool, Crown St, Liverpool, L69 7ZD, UK
| | - Simon J Higgins
- Department of Chemistry, University of Liverpool, Crown St, Liverpool, L69 7ZD, UK
| | - Matthew J Piggott
- School of Molecular Science, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - Hatef Sadeghi
- School of Engineering, University of Warwick, Coventry, CV4 7AL, UK
| | - Richard J Nichols
- Department of Chemistry, University of Liverpool, Crown St, Liverpool, L69 7ZD, UK
| | - Sara Sangtarash
- School of Engineering, University of Warwick, Coventry, CV4 7AL, UK
| | - Andrea Vezzoli
- Department of Chemistry, University of Liverpool, Crown St, Liverpool, L69 7ZD, UK
| | - George A Koutsantonis
- School of Molecular Science, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
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6
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Zhang M, Wu Z, Jia H, Li P, Yang L, Hao J, Wang J, Zhang E, Meng L, Yan Z, Liu Y, Du P, Kong X, Xiao S, Jia C, Guo X. Distinct armchair and zigzag charge transport through single polycyclic aromatics. SCIENCE ADVANCES 2023; 9:eadg4346. [PMID: 37256956 PMCID: PMC10413665 DOI: 10.1126/sciadv.adg4346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 04/27/2023] [Indexed: 06/02/2023]
Abstract
In aromatic systems with large π-conjugated structures, armchair and zigzag configurations can affect each material's electronic properties, determining their performance and generating certain quantum effects. Here, we explore the intrinsic effect of armchair and zigzag pathways on charge transport through single hexabenzocoronene molecules. Theoretical calculations and systematic experimental results from static carbon-based single-molecule junctions and dynamic scanning tunneling microscope break junctions show that charge carriers are preferentially transported along the hexabenzocoronene armchair pathway, and thus, the corresponding current through this pathway is approximately one order of magnitude higher than that through the zigzag pathway. In addition, the molecule with the zigzag pathway has a smaller energy gap. In combination with its lower off-state conductance, it shows a better field-effect performance because of its higher on-off ratio in electrical measurements. This study on charge transport pathways offers a useful perspective for understanding the electronic properties of π-conjugated systems and realizing high-performance molecular nanocircuits toward practical applications.
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Affiliation(s)
- Miao Zhang
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, China
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, China
- The Education Ministry Key Lab of Resource Chemistry, Joint International Research Laboratory of Resource Chemistry, Ministry of Education, Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Frontiers Science Center of Biomimetic Catalysis, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai 200234, China
| | - Zewen Wu
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Hongxing Jia
- Hefei National Research Center for Physical Sciences at the Microscale, Anhui Laboratory of Advanced Photon Science and Technology, CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, iChEM, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui Province 230026, China
| | - Peihui Li
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, China
| | - Lei Yang
- The Education Ministry Key Lab of Resource Chemistry, Joint International Research Laboratory of Resource Chemistry, Ministry of Education, Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Frontiers Science Center of Biomimetic Catalysis, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai 200234, China
| | - Jie Hao
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, China
| | - Jinying Wang
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, China
- Network for Computational Nanotechnology, College of Engineering, Purdue University, 298 Nimitz Dr., West Lafayette, IN 47906, USA
| | - Enyu Zhang
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, China
| | - Linan Meng
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, China
| | - Zhuang Yan
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, China
| | - Yi Liu
- The Education Ministry Key Lab of Resource Chemistry, Joint International Research Laboratory of Resource Chemistry, Ministry of Education, Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Frontiers Science Center of Biomimetic Catalysis, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai 200234, China
| | - Pingwu Du
- Hefei National Research Center for Physical Sciences at the Microscale, Anhui Laboratory of Advanced Photon Science and Technology, CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, iChEM, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui Province 230026, China
| | - Xianghua Kong
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Shengxiong Xiao
- The Education Ministry Key Lab of Resource Chemistry, Joint International Research Laboratory of Resource Chemistry, Ministry of Education, Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Frontiers Science Center of Biomimetic Catalysis, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai 200234, China
| | - Chuancheng Jia
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, China
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, China
| | - Xuefeng Guo
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, China
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, China
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7
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Hameed F, Mohanan M, Ibrahim N, Ochonma C, Rodríguez-López J, Gavvalapalli N. Controlling π-Conjugated Polymer-Acceptor Interactions by Designing Polymers with a Mixture of π-Face Strapped and Nonstrapped Monomers. Macromolecules 2023; 56:3421-3429. [PMID: 38510570 PMCID: PMC10950295 DOI: 10.1021/acs.macromol.3c00175] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/07/2023] [Indexed: 03/22/2024]
Abstract
Controlling π-conjugated polymer-acceptor complex interaction, including the interaction strength and location along the polymer backbone, is central to organic electronics and energy applications. Straps in the strapped π-conjugated polymers mask the π-face of the polymer backbone and hence are useful to control the interactions of the π-face of the polymer backbone with other polymer chains and small molecules compared to the conventional pendant solubilizing chains. Herein, we have synthesized a series of strapped π-conjugated copolymers containing a mixture of strapped and nonstrapped comonomers to control the polymer-acceptor interactions. Simulations confirmed that the acceptor is directed toward the nonstrapped repeat unit. More importantly, strapped copolymers overcome a major drawback of homopolymers and display higher photoinduced photoluminescence (PL) quenching, which is a measure of electron transfer from the polymer to acceptor, compared to that of both the strapped homopolymer and the conventional polymer with pendant solubilizing chains. We have also shown that this strategy applies not only to strapped polymers, but also to the conventional polymers with pendant solubilizing chains. The increase in PL quenching is attributed to the absence of a steric sheath around the comonomers and their random location along the polymer backbone, which enhances the probability of non-neighbor acceptor binding events along the polymer backbone. Thus, by mixing insulated and noninsulated monomers along the polymer backbone, the location of the acceptor along the polymer backbone, polymer-acceptor interaction strength, and the efficiency of photoinduced charge transfer are controllable compared to the homopolymers.
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Affiliation(s)
- Fatima Hameed
- Department
of Chemistry, Georgetown University, Washington, D.C. 20057, United States
- Institute
for Soft Matter Synthesis and Metrology, Georgetown University, Washington, D.C. 20057, United States
| | - Manikandan Mohanan
- Department
of Chemistry, Georgetown University, Washington, D.C. 20057, United States
- Institute
for Soft Matter Synthesis and Metrology, Georgetown University, Washington, D.C. 20057, United States
| | - Nafisa Ibrahim
- Department
of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Charles Ochonma
- Department
of Chemistry, Georgetown University, Washington, D.C. 20057, United States
- Institute
for Soft Matter Synthesis and Metrology, Georgetown University, Washington, D.C. 20057, United States
| | - Joaquín Rodríguez-López
- Department
of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Nagarjuna Gavvalapalli
- Department
of Chemistry, Georgetown University, Washington, D.C. 20057, United States
- Institute
for Soft Matter Synthesis and Metrology, Georgetown University, Washington, D.C. 20057, United States
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8
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Nguyen QV, Thi HL, Truong GL. Chemical Conformation Induced Transport Carrier Switching in Molecular Junction based on Carboxylic-Terminated Thiol Molecules. NANO LETTERS 2022; 22:10147-10153. [PMID: 36475760 DOI: 10.1021/acs.nanolett.2c04031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The paper demonstrates the effect of the chemical conformation of the -COOH group on the transport characteristic including conductance, rectification, and length effect in molecular junctions (MJs) formed by self-assembled monolayers of carboxylic-terminated thiol molecules. For an alkyl chain shorter than C11, the transport mechanism was attributed to a direct off-resonant tunneling of a hole carrier, located at the Au-S interface, whereas a hopping mechanism was assigned to the alkyl chain longer than the C11 chain located at the -COOH group. The hopping mechanism may be operated by electron transport associated with the breaking of the -OH bonding likely driven by a voltage. Importantly, at the C11 alkyl chain, we observed that the transport carrier operating in MJs could change from a hole carrier into an electron carrier. The result strongly proves that the chemical conformation should be considered in analyzing molecular electronics and provides a basis for the rational design of molecular electronic devices.
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Affiliation(s)
- Quyen Van Nguyen
- Department of Advanced Materials Science and Nanotechnology, University of Science and Technology of Hanoi, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi 11307, Vietnam
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Huong Le Thi
- Department of Advanced Materials Science and Nanotechnology, University of Science and Technology of Hanoi, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi 11307, Vietnam
| | - Giang Le Truong
- Institute of Chemistry, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi 11307, Vietnam
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9
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Song J, Zhu J, Wang Z, Liu G. Controlling Charge Transport in Molecular Wires through Transannular π-π Interaction. MATERIALS (BASEL, SWITZERLAND) 2022; 15:7801. [PMID: 36363392 PMCID: PMC9654154 DOI: 10.3390/ma15217801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 10/29/2022] [Accepted: 11/02/2022] [Indexed: 06/16/2023]
Abstract
This paper describes the influence of the transannular π-π interaction in controlling the carrier transport in molecular wires by employing the STM break junction technique. Five pentaphenylene-based molecular wires that contained [2.2]paracyclophane-1,9-dienes (PCD) as the building block were prepared as model compounds. Functional substituents with different electronic properties, ranging from strong acceptors to strong donors, were attached to the top parallel aromatic ring and used as a gate. It was found that the carrier transport features of these molecular wires, such as single-molecule conductance and a charge-tunneling barrier, can be systematically controlled through the transannular π-π interaction.
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Affiliation(s)
- Jianjian Song
- School of Petroleum Engineering, Yangtze University, Wuhan 430100, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang), Zhanjiang 524000, China
- Key Laboratory of Drilling and Production Engineering for Oil and Gas, Hubei Province, Wuhan 430100, China
| | - Jianglin Zhu
- Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang), Zhanjiang 524000, China
| | - Zhaoyong Wang
- China Oilfield Services Ltd. (Blue Ocean BD Hi-Tech Co., Ltd.), Quanzhou 362800, China
| | - Gang Liu
- China Oilfield Services Ltd. (Blue Ocean BD Hi-Tech Co., Ltd.), Quanzhou 362800, China
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10
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Yasui R, Shimizu D, Matsuda K. Large Enhancement of the Single‐Molecular Conductance of a Molecular Wire through a Radical Substituent. Chemistry 2022; 28:e202104242. [DOI: 10.1002/chem.202104242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Indexed: 11/08/2022]
Affiliation(s)
- Ryuto Yasui
- Department of Synthetic Chemistry and Biological Chemistry Graduate School of Engineering Kyoto University Katsura, Nishikyo-ku Kyoto 615-8510 Japan
| | - Daiki Shimizu
- Department of Synthetic Chemistry and Biological Chemistry Graduate School of Engineering Kyoto University Katsura, Nishikyo-ku Kyoto 615-8510 Japan
| | - Kenji Matsuda
- Department of Synthetic Chemistry and Biological Chemistry Graduate School of Engineering Kyoto University Katsura, Nishikyo-ku Kyoto 615-8510 Japan
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11
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Duan P, Wang Y, Chen L, Qu K, Liu J, Zhang QC, Chen ZN, Hong W. Transport Modulation Through Electronegativity Gating in Multiple Nitrogenous Circuits. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2200361. [PMID: 35481610 DOI: 10.1002/smll.202200361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 02/25/2022] [Indexed: 06/14/2023]
Abstract
Investigating the correlations of electron transport between multiple channels shows vital promises for the design of molecule-scale circuits with logic operations. To control the electron transport through multiple channels, the modulation of electronegativity shows an effective frontier orbit control method with high universality to explore the interactions between transport channels. Here, two series of compounds with a single nitrogenous conductive channel (Sg) and dual-channels (Db) are designed to explore the influence of electronegativity on electron tunneling transport. Single-molecule conductance measured via the scanning tunneling microscope break junction technique (STM-BJ) reveals that the conductance of Db series is significantly suppressed as the electronegativity of nitrogen becomes negative, while the suppression on Sg is less obvious. Theoretical calculations confirm that the effect of electronegativity extends to a dispersive range of molecular frameworks owing to the delocalized orbital distribution from the dual-channel structure, resulting in a more significant conductance suppression effect than that on the single-channel. This study provides the experimental and theoretical potentials of electronegativity gating for molecular circuits.
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Affiliation(s)
- Ping Duan
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Yaping Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Lichuan Chen
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Kai Qu
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, P. R. China
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Junyang Liu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Qian-Chong Zhang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, P. R. China
| | - Zhong-Ning Chen
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, P. R. China
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, P. R. China
| | - Wenjing Hong
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
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12
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Charge Transport Characteristics of Molecular Electronic Junctions Studied by Transition Voltage Spectroscopy. MATERIALS 2022; 15:ma15030774. [PMID: 35160719 PMCID: PMC8836750 DOI: 10.3390/ma15030774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 01/11/2022] [Accepted: 01/18/2022] [Indexed: 11/25/2022]
Abstract
The field of molecular electronics is prompted by tremendous opportunities for using a single-molecule and molecular monolayers as active components in integrated circuits. Until now, a wide range of molecular devices exhibiting characteristic functions, such as diodes, transistors, switches, and memory, have been demonstrated. However, a full understanding of the crucial factors that affect charge transport through molecular electronic junctions should yet be accomplished. Remarkably, recent advances in transition voltage spectroscopy (TVS) elucidate that it can provide key quantities for probing the transport characteristics of the junctions, including, for example, the position of the frontier molecular orbital energy relative to the electrode Fermi level and the strength of the molecule–electrode interactions. These parameters are known to be highly associated with charge transport behaviors in molecular systems and can then be used in the design of molecule-based devices with rationally tuned electronic properties. This article highlights the fundamental principle of TVS and then demonstrates its major applications to study the charge transport properties of molecular electronic junctions.
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13
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Zhou YF, Chang WY, Chen JZ, Huang JR, Fu JY, Zhang JN, Pei LQ, Wang YH, Jin S, Zhou XS. Substituent-mediated quantum interference toward a giant single-molecule conductance variation. NANOTECHNOLOGY 2021; 33:095201. [PMID: 34798622 DOI: 10.1088/1361-6528/ac3b84] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 11/19/2021] [Indexed: 06/13/2023]
Abstract
Quantum interference (QI) in single molecular junctions shows a promising perspective for realizing conceptual nanoelectronics. However, controlling and modulating the QI remains a big challenge. Herein, two-type substituents at different positions ofmeta-linked benzene, namely electron-donating methoxy (-OMe) and electron-withdrawing nitryl (-NO2), are designed and synthesized to investigate the substituent effects on QI. The calculated transmission coefficientsT(E) indicates that -OMe and -NO2could remove the antiresonance and destructive quantum interference (DQI)-induced transmission dips at position 2. -OMe could raise the antiresonance energy at position 4 while -NO2groups removes the DQI features. For substituents at position 5, both of them are nonactive for tuning QI. The conductance measurements by scanning tunneling microscopy break junction show a good agreement with the theoretical prediction. More than two order of magnitude single-molecule conductance on/off ratio could be achieved at the different positions of -NO2substituent groups at room temperature. The present work proves chemical substituents can be used for tuning QI features in single molecular junctions, which provides a feasible way toward realization of high-performance molecular devices.
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Affiliation(s)
- Yi-Fan Zhou
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, People's Republic of China
| | - Wen-Yan Chang
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Jing-Zhe Chen
- Department of Physics, Shanghai University, Shanghai 200444, People's Republic of China
| | - Jun-Ren Huang
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, People's Republic of China
| | - Jia-Ying Fu
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, People's Republic of China
| | - Jin-Na Zhang
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Lin-Qi Pei
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Ya-Hao Wang
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, People's Republic of China
| | - Shan Jin
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Xiao-Shun Zhou
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, People's Republic of China
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14
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Lillis R, Thomas MR, Mohanan M, Gavvalapalli N. Enhancing Insulated Conjugated Polymer Fluorescence Quenching by Incorporating Dithia[3.3]paracyclophanes. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ryan Lillis
- Department of Chemistry, Institute for Soft Matter Synthesis and Metrology, Georgetown University, 3700 O St NW, Washington, D.C. 20057, United States
| | - Maximillian R. Thomas
- Department of Chemistry, Institute for Soft Matter Synthesis and Metrology, Georgetown University, 3700 O St NW, Washington, D.C. 20057, United States
| | - Manikandan Mohanan
- Department of Chemistry, Institute for Soft Matter Synthesis and Metrology, Georgetown University, 3700 O St NW, Washington, D.C. 20057, United States
| | - Nagarjuna Gavvalapalli
- Department of Chemistry, Institute for Soft Matter Synthesis and Metrology, Georgetown University, 3700 O St NW, Washington, D.C. 20057, United States
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15
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Ivie JA, Bamberger ND, Parida KN, Shepard S, Dyer D, Saraiva-Souza A, Himmelhuber R, McGrath DV, Smeu M, Monti OLA. Correlated Energy-Level Alignment Effects Determine Substituent-Tuned Single-Molecule Conductance. ACS APPLIED MATERIALS & INTERFACES 2021; 13:4267-4277. [PMID: 33438990 DOI: 10.1021/acsami.0c19404] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The rational design of single-molecule electrical components requires a deep and predictive understanding of structure-function relationships. Here, we explore the relationship between chemical substituents and the conductance of metal-single-molecule-metal junctions, using functionalized oligophenylenevinylenes as a model system. Using a combination of mechanically controlled break-junction experiments and various levels of theory including non-equilibrium Green's functions, we demonstrate that the connection between gas-phase molecular electronic structure and in-junction molecular conductance is complicated by the involvement of multiple mutually correlated and opposing effects that contribute to energy-level alignment in the junction. We propose that these opposing correlations represent powerful new "design principles" because their physical origins make them broadly applicable, and they are capable of predicting the direction and relative magnitude of observed conductance trends. In particular, we show that they are consistent with the observed conductance variability not just within our own experimental results but also within disparate molecular series reported in the literature and, crucially, with the trend in variability across these molecular series, which previous simple models fail to explain. The design principles introduced here can therefore aid in both screening and suggesting novel design strategies for maximizing conductance tunability in single-molecule systems.
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Affiliation(s)
- Jeffrey A Ivie
- Department of Chemistry and Biochemistry, University of Arizona, 1306 E. University Blvd., Tucson, Arizona 85721, United States
| | - Nathan D Bamberger
- Department of Chemistry and Biochemistry, University of Arizona, 1306 E. University Blvd., Tucson, Arizona 85721, United States
| | - Keshaba N Parida
- Department of Chemistry and Biochemistry, University of Arizona, 1306 E. University Blvd., Tucson, Arizona 85721, United States
| | - Stuart Shepard
- Department of Physics, Binghamton University-SUNY, 4400 Vestal Parkway East, Binghamton, New York 13902, United States
| | - Dylan Dyer
- Department of Chemistry and Biochemistry, University of Arizona, 1306 E. University Blvd., Tucson, Arizona 85721, United States
| | - Aldilene Saraiva-Souza
- Departamento de Física, Universidade Federal do Maranhão, São Luís, Massachusetts 65080-805, Brazil
| | - Roland Himmelhuber
- College of Optical Sciences, University of Arizona, 1630 E. University Blvd., Tucson, Arizona 85721, United States
| | - Dominic V McGrath
- Department of Chemistry and Biochemistry, University of Arizona, 1306 E. University Blvd., Tucson, Arizona 85721, United States
| | - Manuel Smeu
- Department of Physics, Binghamton University-SUNY, 4400 Vestal Parkway East, Binghamton, New York 13902, United States
| | - Oliver L A Monti
- Department of Chemistry and Biochemistry, University of Arizona, 1306 E. University Blvd., Tucson, Arizona 85721, United States
- Department of Physics, University of Arizona, 1118 E. Fourth Street, Tucson, Arizona 85721, United States
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16
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Yan JF, Zhu GG, Yuan Y, Lin CX, Huang SP, Yuan YF. Carborane bridged ferrocenyl conjugated molecules: synthesis, structure, electrochemistry and photophysical properties. NEW J CHEM 2020. [DOI: 10.1039/d0nj00826e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
mono- and bis-carborane bridged ferrocenyl conjugated molecules 8–11 have been synthesized and systematically analyzed.
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Affiliation(s)
- Jian-Feng Yan
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University)
- Department of Chemistry
- Fuzhou University
- Fuzhou 350108
- People's Republic of China
| | - Gai-Ge Zhu
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University)
- Department of Chemistry
- Fuzhou University
- Fuzhou 350108
- People's Republic of China
| | - Ye Yuan
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University)
- Department of Chemistry
- Fuzhou University
- Fuzhou 350108
- People's Republic of China
| | - Cai-Xia Lin
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University)
- Department of Chemistry
- Fuzhou University
- Fuzhou 350108
- People's Republic of China
| | - Shu-Ping Huang
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University)
- Department of Chemistry
- Fuzhou University
- Fuzhou 350108
- People's Republic of China
| | - Yao-Feng Yuan
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University)
- Department of Chemistry
- Fuzhou University
- Fuzhou 350108
- People's Republic of China
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17
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Naghibi S, Ismael AK, Vezzoli A, Al-Khaykanee MK, Zheng X, Grace IM, Bethell D, Higgins SJ, Lambert CJ, Nichols RJ. Synthetic Control of Quantum Interference by Regulating Charge on a Single Atom in Heteroaromatic Molecular Junctions. J Phys Chem Lett 2019; 10:6419-6424. [PMID: 31577147 PMCID: PMC7007252 DOI: 10.1021/acs.jpclett.9b02319] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
A key area of activity in contemporary molecular electronics is the chemical control of conductance of molecular junctions and devices. Here we study and modify a range of pyrrolodipyridines (carbazole-like) molecular wires. We are able to change the electrical conductance and quantum interference patterns by chemically regulating the bridging nitrogen atom in the tricyclic ring system. A series of eight different N-substituted pyrrolodipyridines has been synthesized and subjected to single-molecule electrical characterization using an STM break junction. Correlations of these experimental data with theoretical calculations underline the importance of the pyrrolic nitrogen in facilitating conductance across the molecular bridge and controlling quantum interference. The large chemical modulation for the meta-connected series is not apparent for the para-series, showing the competition between (i) meta-connectivity quantum interference phenomena and (ii) the ability of the pyrrolic nitrogen to facilitate conductance, that can be modulated by chemical substitution.
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Affiliation(s)
- Saman Naghibi
- Department
of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, U.K.
| | - Ali K. Ismael
- Department
of Physics, Lancaster University, Lancaster LA1 4YB, U.K.
- Department
of Physics, College of Education for Pure Science, Tikrit University, Tikrit 34001, Iraq
| | - Andrea Vezzoli
- Department
of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, U.K.
- E-mail:
| | - Mohsin K. Al-Khaykanee
- Department
of Physics, Lancaster University, Lancaster LA1 4YB, U.K.
- Department
of Physics, College of Science, University
of Babylon, Babylon 51002, Iraq
| | - Xijia Zheng
- Department
of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, U.K.
| | - Iain M. Grace
- Department
of Physics, Lancaster University, Lancaster LA1 4YB, U.K.
| | - Donald Bethell
- Department
of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, U.K.
| | - Simon J. Higgins
- Department
of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, U.K.
| | - Colin J. Lambert
- Department
of Physics, Lancaster University, Lancaster LA1 4YB, U.K.
- E-mail:
| | - Richard J. Nichols
- Department
of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, U.K.
- E-mail:
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18
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Side-group chemical gating via reversible optical and electric control in a single molecule transistor. Nat Commun 2019; 10:1450. [PMID: 30926785 PMCID: PMC6440973 DOI: 10.1038/s41467-019-09120-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 02/24/2019] [Indexed: 11/14/2022] Open
Abstract
By taking advantage of large changes in geometric and electronic structure during the reversible trans–cis isomerisation, azobenzene derivatives have been widely studied for potential applications in information processing and digital storage devices. Here we report an unusual discovery of unambiguous conductance switching upon light and electric field-induced isomerisation of azobenzene in a robust single-molecule electronic device for the first time. Both experimental and theoretical data consistently demonstrate that the azobenzene sidegroup serves as a viable chemical gate controlled by electric field, which efficiently modulates the energy difference of trans and cis forms as well as the energy barrier of isomerisation. In conjunction with photoinduced switching at low biases, these results afford a chemically-gateable, fully-reversible, two-mode, single-molecule transistor, offering a fresh perspective for creating future multifunctional single-molecule optoelectronic devices in a practical way. It remains a challenge to fully control molecular electronics. Here, Meng et al. show a reversible two-mode single-molecule switch, where the conductance through the molecular backbone is controlled by an in situ chemical gating via bias-dependent trans–cis isomerisation on an azobenzene sidegroup.
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19
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Awais MA, Cai Z, Zhang N, Yu L. Molecular Design towards Controlling Charge Transport. Chemistry 2018; 24:17180-17187. [DOI: 10.1002/chem.201803054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 08/04/2018] [Indexed: 11/10/2022]
Affiliation(s)
- Mohammad Ahmad Awais
- Department of Chemistry and The James Franck Institute; The University of Chicago; 1929 E 57th Street Chicago IL 60637 USA
| | - Zhengxu Cai
- Beijing Key Laboratory of Construction Tailorable Advanced Functional, Materials and Green Applications; School of Materials Science and Engineering; Beijing Institute of Technology; 25 South Zhongguancun Street Beijing 100081 P. R. China
| | - Na Zhang
- Department of Chemistry and The James Franck Institute; The University of Chicago; 1929 E 57th Street Chicago IL 60637 USA
| | - Luping Yu
- Department of Chemistry and The James Franck Institute; The University of Chicago; 1929 E 57th Street Chicago IL 60637 USA
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20
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Gu C, Hu C, Wei Y, Lin D, Jia C, Li M, Su D, Guan J, Xia A, Xie L, Nitzan A, Guo H, Guo X. Label-Free Dynamic Detection of Single-Molecule Nucleophilic-Substitution Reactions. NANO LETTERS 2018; 18:4156-4162. [PMID: 29874453 DOI: 10.1021/acs.nanolett.8b00949] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The mechanisms of chemical reactions, including the transformation pathways of the electronic and geometric structures of molecules, are crucial for comprehending the essence and developing new chemistry. However, it is extremely difficult to realize at the single-molecule level. Here, we report a single-molecule approach capable of electrically probing stochastic fluctuations under equilibrium conditions and elucidating time trajectories of single species in non-equilibrated systems. Through molecular engineering, a single molecular wire containing a functional center of 9-phenyl-9-fluorenol was covalently wired into nanogapped graphene electrodes to form stable single-molecule junctions. Both experimental and theoretical studies consistently demonstrate and interpret the direct measurement of the formation dynamics of individual carbocation intermediates with a strong solvent dependence in a nucleophilic-substitution reaction. We also show the kinetic process of competitive transitions between acetate and bromide species, which is inevitable through a carbocation intermediate, confirming the classical mechanism. This unique method creates plenty of opportunities for carrying out single-molecule dynamics or biophysics investigations in broad fields beyond reaction chemistry through molecular design and engineering.
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Affiliation(s)
- Chunhui Gu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , PR China
| | - Chen Hu
- Center for the Physics of Materials and Department of Physics , McGill University , Montreal , Quebec H3A 2T8 , Canada
| | - Ying Wei
- Center for Molecular Systems and Organic Devices, Key Laboratory for Organic Electronics & Information Displays and Institute of Advanced Materials , Nanjing University of Posts & Telecommunications , Nanjing 210023 , PR China
| | - Dongqing Lin
- Center for Molecular Systems and Organic Devices, Key Laboratory for Organic Electronics & Information Displays and Institute of Advanced Materials , Nanjing University of Posts & Telecommunications , Nanjing 210023 , PR China
| | - Chuancheng Jia
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , PR China
| | - Mingzhi Li
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , PR China
| | - Dingkai Su
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , PR China
| | - Jianxin Guan
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , PR China
| | - Andong Xia
- Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , PR China
| | - Linghai Xie
- Center for Molecular Systems and Organic Devices, Key Laboratory for Organic Electronics & Information Displays and Institute of Advanced Materials , Nanjing University of Posts & Telecommunications , Nanjing 210023 , PR China
| | - Abraham Nitzan
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Hong Guo
- Center for the Physics of Materials and Department of Physics , McGill University , Montreal , Quebec H3A 2T8 , Canada
| | - Xuefeng Guo
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , PR China
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21
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Xin N, Jia C, Wang J, Wang S, Li M, Gong Y, Zhang G, Zhu D, Guo X. Thermally Activated Tunneling Transition in a Photoswitchable Single-Molecule Electrical Junction. J Phys Chem Lett 2017; 8:2849-2854. [PMID: 28598631 DOI: 10.1021/acs.jpclett.7b01063] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Exploring the charge transport process in molecular junctions is essential to the development of molecular electronics. Here, we investigate the temperature-dependent charge transport mechanism of carbon electrode-diarylethene single-molecule junctions, which possess photocontrollable molecular orbital energy levels due to reversible photoisomerization of individual diarylethenes between open and closed conformations. Both the experimental results and theoretical calculations consistently demonstrate that the vibronic coupling (thermally activated at the proper temperature) drives the transition of charge transport in the junctions from coherent tunneling to incoherent transport. Due to the subtle electron-phonon coupling effect, incoherent transport in the junctions proves to have different activation energies, depending on the photoswitchable molecular energy levels of two different conformations. These results improve fundamental understanding of charge transport mechanisms in molecular junctions and should lead to the rapid development of functional molecular devices toward practical applications.
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Affiliation(s)
- Na Xin
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, People's Republic of China
| | - Chuancheng Jia
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, People's Republic of China
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China
| | - Jinying Wang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, People's Republic of China
| | - Shuopei Wang
- Institute of Physics, Chinese Academy of Sciences , Beijing 100190, People's Republic of China
| | - Mingliang Li
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, People's Republic of China
| | - Yao Gong
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, People's Republic of China
| | - Guangyu Zhang
- Institute of Physics, Chinese Academy of Sciences , Beijing 100190, People's Republic of China
| | - Daoben Zhu
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China
| | - Xuefeng Guo
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, People's Republic of China
- Department of Materials Science and Engineering, College of Engineering, Peking University , Beijing 100871, People's Republic of China
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22
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Zhang N, Lo WY, Jose A, Cai Z, Li L, Yu L. A Single-Molecular AND Gate Operated with Two Orthogonal Switching Mechanisms. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1701248. [PMID: 28512786 DOI: 10.1002/adma.201701248] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Revised: 03/29/2017] [Indexed: 06/07/2023]
Abstract
Single-molecular electronics is a potential solution to nanoscale electronic devices. While simple functional single-molecule devices such as diodes, switches, and wires are well studied, complex single-molecular systems with multiple functional units are rarely investigated. Here, a single-molecule AND logic gate is constructed from a proton-switchable edge-on gated pyridinoparacyclophane unit with a light-switchable diarylethene unit. The AND gate can be controlled orthogonally by light and protonation and produce desired electrical output at room temperature. The AND gate shows high conductivity when treated with UV light and in the neutral state, and low conductivity when treated either with visible light or acid. A conductance difference of 7.3 is observed for the switching from the highest conducting state to second-highest conducting state and a conductance ratio of 94 is observed between the most and least conducting states. The orthogonality of the two stimuli is further demonstrated by UV-vis, NMR, and density function theory calculations. This is a demonstration of concept of constructing a complex single-molecule electronic device from two coupled functional units.
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Affiliation(s)
- Na Zhang
- Department of Chemistry and The James Franck Institute, The University of Chicago, 929 E 57th Street, Chicago, IL, 60637, USA
| | - Wai-Yip Lo
- Department of Chemistry and The James Franck Institute, The University of Chicago, 929 E 57th Street, Chicago, IL, 60637, USA
| | - Anex Jose
- Department of Chemistry and The James Franck Institute, The University of Chicago, 929 E 57th Street, Chicago, IL, 60637, USA
| | - Zhengxu Cai
- Department of Chemistry and The James Franck Institute, The University of Chicago, 929 E 57th Street, Chicago, IL, 60637, USA
| | - Lianwei Li
- Department of Chemistry and The James Franck Institute, The University of Chicago, 929 E 57th Street, Chicago, IL, 60637, USA
| | - Luping Yu
- Department of Chemistry and The James Franck Institute, The University of Chicago, 929 E 57th Street, Chicago, IL, 60637, USA
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23
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Nozaki D, Schmidt WG. Current density analysis of electron transport through molecular wires in open quantum systems. J Comput Chem 2017; 38:1685-1692. [PMID: 28480601 DOI: 10.1002/jcc.24812] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 03/29/2017] [Accepted: 03/30/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Daijiro Nozaki
- Lehrstuhl für Theoretische Materialphysik, Universität Paderborn; Warburger Str. 100 Paderborn 33098 Germany
| | - Wolf Gero Schmidt
- Lehrstuhl für Theoretische Materialphysik, Universität Paderborn; Warburger Str. 100 Paderborn 33098 Germany
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24
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Johnson TK, Ivie JA, Jaruvang J, Monti OLA. Fast sensitive amplifier for two-probe conductance measurements in single molecule break junctions. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:033904. [PMID: 28372377 DOI: 10.1063/1.4978962] [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
We demonstrate an amplifier based on the Wheatstone bridge designed specifically for use in single molecule break junctions. This amplifier exhibits superior performance due to its large bandwidth, flat frequency response, and high sensitivity. The amplifier is capable of measuring conductance values from 102 to 10-6G0 (G0 = 2e2/h), while maintaining a bandwidth in excess of 20 kHz, and shows remarkable resolution in the molecular conductance regime of 10-2 to 10-5 G0.
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Affiliation(s)
- Tyler K Johnson
- Department of Chemistry and Biochemistry, The University of Arizona, 1306 E. University Blvd., Tucson, Arizona 85721, USA
| | - Jeffrey A Ivie
- Department of Chemistry and Biochemistry, The University of Arizona, 1306 E. University Blvd., Tucson, Arizona 85721, USA
| | - Jason Jaruvang
- Department of Chemical and Environmental Engineering, The University of Arizona, 1133 James E. Rogers Way, Tucson, Arizona 85721, USA
| | - Oliver L A Monti
- Department of Chemistry and Biochemistry, The University of Arizona, 1306 E. University Blvd., Tucson, Arizona 85721, USA
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25
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Zhang N, Lo WY, Cai Z, Li L, Yu L. Molecular Rectification Tuned by Through-Space Gating Effect. NANO LETTERS 2017; 17:308-312. [PMID: 28073271 DOI: 10.1021/acs.nanolett.6b04110] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Inspired by transistors and electron transfer in proteins, we designed a group of pyridinoparacyclophane based diodes to study the through-space electronic gating effect on molecular rectification. It was shown that an edge-on gate effectively tunes the rectification ratio of a diode via through-space interaction. Higher rectification ratio was obtained for more electron-rich gating groups. The transition voltage spectroscopy showed that the forward transition voltage is correlated to the Hammett parameter of the gating group. Combining theoretical calculation and experimental data, we proposed that the change in rectification was induced by a shift in HOMO level both spatially and energetically. This design principle based on through-space edge-on gate is demonstrated on molecular wires, switches, and now diodes, showing the potential of molecular design in increasing the complexity of single-molecule electronic devices.
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Affiliation(s)
- Na Zhang
- Department of Chemistry and the James Franck Institute, The University of Chicago , 929 E 57th Street, Chicago, Illinois 60637, United States
| | - Wai-Yip Lo
- Department of Chemistry and the James Franck Institute, The University of Chicago , 929 E 57th Street, Chicago, Illinois 60637, United States
| | - Zhengxu Cai
- Department of Chemistry and the James Franck Institute, The University of Chicago , 929 E 57th Street, Chicago, Illinois 60637, United States
| | - Lianwei Li
- Department of Chemistry and the James Franck Institute, The University of Chicago , 929 E 57th Street, Chicago, Illinois 60637, United States
| | - Luping Yu
- Department of Chemistry and the James Franck Institute, The University of Chicago , 929 E 57th Street, Chicago, Illinois 60637, United States
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26
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Lo WY, Zhang N, Cai Z, Li L, Yu L. Beyond Molecular Wires: Design Molecular Electronic Functions Based on Dipolar Effect. Acc Chem Res 2016; 49:1852-63. [PMID: 27575979 DOI: 10.1021/acs.accounts.6b00305] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
As the semiconductor companies officially abandoned the pursuit of Moore's law, the limitation of silicone-based semiconductor electronic devices is approaching. Single molecular devices are considered as a potential solution to overcome the physical barriers caused by quantum interferences because the intermolecular interactions are mainly through weak van der Waals force between molecular building blocks. In this bottom-up approach, components are built from atoms up, allowing great control over the molecular properties. Moreover, single molecular devices are powerful tools to understand quantum physics, reaction mechanism, and electron and charge transfer processes in organic semiconductors and molecules. So far, a great deal of effort is focused on understanding charge transport through organic single-molecular wires. However, to control charge transport, molecular diodes, switches, transistors, and memories are crucial. Significant progress in these topics has been achieved in the past years. The introduction and advances of scanning tunneling microscope break-junction (STM-BJ) techniques have led to more detailed characterization of new molecular structures. The modern organic chemistry provides an efficient access to a variety of functional moieties in single molecular device. These moieties have the potential to be incorporated in miniature circuits or incorporated as parts in molecular machines, bioelectronics devices, and bottom-up molecular devices. In this Account, we discuss progress mainly made in our lab in designing and characterizing organic single-molecular electronic components beyond molecular wires and with varied functions. We have synthesized and demonstrated molecular diodes with p-n junction structures through various scanning probe microscopy techniques. The assembly of the molecular diodes was achieved by using Langmuir-Blodgett technique or thiol/gold self-assembly chemistry with orthogonal protecting groups. We have thoroughly investigated the rectification effect of different types of p-n junction diodes and its modification by structural and external effects. Through a combination of structural modifications, low temperature study, and quantum mechanical calculations, we showed that the origin of the rectification in these molecules can be attributed to the effect of dipolar field. Further studies on charge transport through transition metal complexes and anchoring group effect supported this conclusion. Most recently, a model system of molecular transistor was synthesized and demonstrated by STM-BJ technique. The gating effect in the molecular wire originated from the tuning of the energy levels via dipolar field and can be turned on/off by dipolar field and chemical stimulation. This is the first example of gated charge transport in molecular electronics.
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Affiliation(s)
- Wai-Yip Lo
- Department
of Chemistry and
the James Franck Institute, The University of Chicago, 929 E 57th
Street, Chicago, Illinois 60637, United States
| | - Na Zhang
- Department
of Chemistry and
the James Franck Institute, The University of Chicago, 929 E 57th
Street, Chicago, Illinois 60637, United States
| | - Zhengxu Cai
- Department
of Chemistry and
the James Franck Institute, The University of Chicago, 929 E 57th
Street, Chicago, Illinois 60637, United States
| | - Lianwei Li
- Department
of Chemistry and
the James Franck Institute, The University of Chicago, 929 E 57th
Street, Chicago, Illinois 60637, United States
| | - Luping Yu
- Department
of Chemistry and
the James Franck Institute, The University of Chicago, 929 E 57th
Street, Chicago, Illinois 60637, United States
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27
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Cai Z, Lo WY, Zheng T, Li L, Zhang N, Hu Y, Yu L. Exceptional Single-Molecule Transport Properties of Ladder-Type Heteroacene Molecular Wires. J Am Chem Soc 2016; 138:10630-5. [PMID: 27488536 DOI: 10.1021/jacs.6b05983] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A series of ladder-type fused heteroacenes consisting of thiophenes and benzothiophenes were synthesized and functionalized with thiol groups for single-molecule electrical measurements via a scanning tunneling microscopy break-junction method. It was found that this molecular wire system possesses exceptional charge transport properties with weak length dependence. The tunneling decay constant β was estimated to be 0.088 and 0.047 Å(-1) under 0.1 and 0.5 bias, respectively, which is one of the lowest β values among other non-metal-containing molecular wires, indicating that a planar ladder structure favors charge transport. Transition voltage spectroscopy showed that the energy barrier decreases as the length of the molecule increases. The general trend of the energy offsets derived from the transition voltage via the Newns-Anderson model agrees well with that of the Fermi/HOMO energy level difference. Nonequilibrium Green's function/density functional theory was used to further investigate the transport process in these molecular wires.
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Affiliation(s)
- Zhengxu Cai
- Department of Chemistry and the James Franck Institute, The University of Chicago , 929 East 57th Street, Chicago, Illinois 60637, United States
| | - Wai-Yip Lo
- Department of Chemistry and the James Franck Institute, The University of Chicago , 929 East 57th Street, Chicago, Illinois 60637, United States
| | - Tianyue Zheng
- Department of Chemistry and the James Franck Institute, The University of Chicago , 929 East 57th Street, Chicago, Illinois 60637, United States
| | - Lianwei Li
- Department of Chemistry and the James Franck Institute, The University of Chicago , 929 East 57th Street, Chicago, Illinois 60637, United States
| | - Na Zhang
- Department of Chemistry and the James Franck Institute, The University of Chicago , 929 East 57th Street, Chicago, Illinois 60637, United States
| | - Yubing Hu
- Department of Chemistry and the James Franck Institute, The University of Chicago , 929 East 57th Street, Chicago, Illinois 60637, United States
| | - Luping Yu
- Department of Chemistry and the James Franck Institute, The University of Chicago , 929 East 57th Street, Chicago, Illinois 60637, United States
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28
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Cai Z, Li L, Lo WY, Zhao D, Wu Q, Zhang N, Su YA, Chen W, Yu L. Controlled Self-Assembly of Cyclophane Amphiphiles: From 1D Nanofibers to Ultrathin 2D Topological Structures. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b00860] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zhengxu Cai
- Department
of Chemistry and the James Franck Institute, The University of Chicago, 929 E 57th Street, Chicago, Illinois 60637, United States
| | - Lianwei Li
- Department
of Chemistry and the James Franck Institute, The University of Chicago, 929 E 57th Street, Chicago, Illinois 60637, United States
| | - Wai-Yip Lo
- Department
of Chemistry and the James Franck Institute, The University of Chicago, 929 E 57th Street, Chicago, Illinois 60637, United States
| | - Donglin Zhao
- Department
of Chemistry and the James Franck Institute, The University of Chicago, 929 E 57th Street, Chicago, Illinois 60637, United States
| | - Qinghe Wu
- Department
of Chemistry and the James Franck Institute, The University of Chicago, 929 E 57th Street, Chicago, Illinois 60637, United States
| | - Na Zhang
- Department
of Chemistry and the James Franck Institute, The University of Chicago, 929 E 57th Street, Chicago, Illinois 60637, United States
| | - Yu-An Su
- Materials
Science Division, Argonne National Laboratory, 9700 Cass Avenue, Lemont, Illinois 60439, United States
| | - Wei Chen
- Materials
Science Division, Argonne National Laboratory, 9700 Cass Avenue, Lemont, Illinois 60439, United States
- Institute
for Molecular Engineering, The University of Chicago, 5640 South
Ellis Avenue, Chicago, Illinois 60637, United States
| | - Luping Yu
- Department
of Chemistry and the James Franck Institute, The University of Chicago, 929 E 57th Street, Chicago, Illinois 60637, United States
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29
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Li L, Lo WY, Cai Z, Zhang N, Yu L. Proton-triggered switch based on a molecular transistor with edge-on gate. Chem Sci 2016; 7:3137-3141. [PMID: 29997804 PMCID: PMC6005264 DOI: 10.1039/c6sc00152a] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 01/19/2016] [Indexed: 11/21/2022] Open
Abstract
The manipulation of charge transport through single molecules so that electronic information can be controlled is a basic challenge that is important for both fundamental understanding of the mechanisms and the potential applications in single-molecule technologies. This paper reports the influence of protonation on the gating effect in a series of molecular wires utilizing a pyridinoparacyclophane (PPC) moiety as the edge-on gate. It was found that the molecular conductance, transition voltage, and the corresponding tunnelling barriers can be reversibly switched by the protonation/deprotonation process of the nitrogen atom on the PPC pyridine ring. It was found that protonation levels off the tunnelling barrier of different molecules and converts p-type molecular wires into n-type, reversibly.
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Affiliation(s)
- Lianwei Li
- Department of Chemistry and the James Franck Institute , The University of Chicago , 929 E 57th Street , Chicago , IL 60637 , USA .
| | - Wai-Yip Lo
- Department of Chemistry and the James Franck Institute , The University of Chicago , 929 E 57th Street , Chicago , IL 60637 , USA .
| | - Zhengxu Cai
- Department of Chemistry and the James Franck Institute , The University of Chicago , 929 E 57th Street , Chicago , IL 60637 , USA .
| | - Na Zhang
- Department of Chemistry and the James Franck Institute , The University of Chicago , 929 E 57th Street , Chicago , IL 60637 , USA .
| | - Luping Yu
- Department of Chemistry and the James Franck Institute , The University of Chicago , 929 E 57th Street , Chicago , IL 60637 , USA .
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30
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Xiang D, Wang X, Jia C, Lee T, Guo X. Molecular-Scale Electronics: From Concept to Function. Chem Rev 2016; 116:4318-440. [DOI: 10.1021/acs.chemrev.5b00680] [Citation(s) in RCA: 816] [Impact Index Per Article: 102.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Dong Xiang
- Beijing
National Laboratory for Molecular Sciences, State Key Laboratory for
Structural Chemistry of Unstable and Stable Species, College of Chemistry
and Molecular Engineering, Peking University, Beijing 100871, China
- Key
Laboratory of Optical Information Science and Technology, Institute
of Modern Optics, College of Electronic Information and Optical Engineering, Nankai University, Tianjin 300071, China
| | - Xiaolong Wang
- Beijing
National Laboratory for Molecular Sciences, State Key Laboratory for
Structural Chemistry of Unstable and Stable Species, College of Chemistry
and Molecular Engineering, Peking University, Beijing 100871, China
| | - Chuancheng Jia
- Beijing
National Laboratory for Molecular Sciences, State Key Laboratory for
Structural Chemistry of Unstable and Stable Species, College of Chemistry
and Molecular Engineering, Peking University, Beijing 100871, China
| | - Takhee Lee
- Department
of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul 08826, Korea
| | - Xuefeng Guo
- Beijing
National Laboratory for Molecular Sciences, State Key Laboratory for
Structural Chemistry of Unstable and Stable Species, College of Chemistry
and Molecular Engineering, Peking University, Beijing 100871, China
- Department
of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China
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31
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Bâldea I. Important issues facing model-based approaches to tunneling transport in molecular junctions. Phys Chem Chem Phys 2015; 17:20217-30. [PMID: 26186139 DOI: 10.1039/c5cp02595h] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Extensive studies on thin films indicated a generic cubic current-voltage I-V dependence as a salient feature of charge transport by tunneling. A quick glance at I-V data for molecular junctions suggests a qualitatively similar behavior. This would render model-based studies almost irrelevant, since, whatever the model, its parameters can always be adjusted to fit symmetric (asymmetric) I-V curves characterized by two (three) expansion coefficients. Here, we systematically examine popular models based on tunneling barriers or tight-binding pictures and demonstrate that, for a quantitative description at biases of interest (V slightly higher than the transition voltage Vt), cubic expansions do not suffice. A detailed collection of analytical formulae as well as their conditions of applicability is presented to facilitate experimentalist colleagues to process and interpret their experimental data obtained by measuring currents in molecular junctions. We discuss in detail the limits of applicability of the various models and emphasize that uncritically adjusting the model parameters to experiment may be unjustified because the values deduced in this way may fall in ranges rendering a specific model invalid or incompatible to ab initio estimates. We exemplify with the benchmark case of oligophenylene-based junctions, for which the results of ab initio quantum chemical calculations are also reported. As a specific issue, we address the impact of the spatial potential profile and show that it is not notable up to biases V ≳ Vt, unlike at higher biases, where it may be responsible for negative differential resistance effects.
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Affiliation(s)
- Ioan Bâldea
- Theoretische Chemie, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg, Germany.
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