Molecular Electronics: Light-Induced Switching of Tunable Single-Molecule Junctions (Adv. Sci. 5/2015)

We present anab initiostudy of the use of carbon-based tips as electrodes in single-molecule junctions. We show that carbon tips can be combined with other carbon nanostructures to form all-carbon molecular junctions with molecules like benzene or C60. Results show that the use of carbon tips can lead to conductive molecular junctions and open new perspectives in all-carbon molecular electronics.

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Role of solvents in the electronic transport properties of single-molecule junctions

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.7.99 ◽

2016 ◽

Vol 7 ◽

pp. 1055-1067 ◽

Cited By ~ 5

Author(s):

Katharina Luka-Guth ◽

Sebastian Hambsch ◽

Andreas Bloch ◽

Philipp Ehrenreich ◽

Bernd Michael Briechle ◽

...

Keyword(s):

Molecular Electronics ◽

Single Molecule ◽

Current Voltage ◽

Tunnel Barriers ◽

Single Molecule Junctions ◽

Level Model ◽

Current Voltage Characteristics ◽

Solvent Molecules ◽

Narrow Gaps

We report on an experimental study of the charge transport through tunnel gaps formed by adjustable gold electrodes immersed into different solvents that are commonly used in the field of molecular electronics (ethanol, toluene, mesitylene, 1,2,4-trichlorobenzene, isopropanol, toluene/tetrahydrofuran mixtures) for the study of single-molecule contacts of functional molecules. We present measurements of the conductance as a function of gap width, conductance histograms as well as current–voltage characteristics of narrow gaps and discuss them in terms of the Simmons model, which is the standard model for describing transport via tunnel barriers, and the resonant single-level model, often applied to single-molecule junctions. One of our conclusions is that stable junctions may form from solvents as well and that both conductance–distance traces and current–voltage characteristics have to be studied to distinguish between contacts of solvent molecules and of molecules under study.

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Single-molecule junctions for molecular electronics

Journal of Materials Chemistry C ◽

10.1039/c6tc03268k ◽

2016 ◽

Vol 4 (38) ◽

pp. 8842-8858 ◽

Cited By ~ 41

Author(s):

Yuki Komoto ◽

Shintaro Fujii ◽

Madoka Iwane ◽

Manabu Kiguchi

Keyword(s):

Molecular Electronics ◽

Single Molecule ◽

Unique Structure ◽

Nano Material ◽

Single Molecule Junctions ◽

Molecule Junction ◽

Single Molecule Junction ◽

Low Dimensional

A single-molecule junction shows novel functionalities caused by its unique structure of a low-dimensional nano-material with two metal–molecule interfaces.

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Redox-addressable single-molecule junctions incorporating a persistent organic radical

10.26434/chemrxiv-2021-3lqf7 ◽

2021 ◽

Author(s):

Saman Naghibi ◽

Sara Sangtarash ◽

Varshini J. Kumar ◽

Jian-Zhong Wu ◽

Martyna M. Judd ◽

...

Keyword(s):

Molecular Electronics ◽

Single Molecule ◽

Closed Shell ◽

Open Shell ◽

Organic Radical ◽

Molecular Junction ◽

Ambient Conditions ◽

Scanning Tunnelling Microscope ◽

Ambient Temperatures ◽

Single Molecule Junctions

The integration of radical (open-shell) species into single-molecule junctions at non-cryogenic temperatures is a key to unlocking the potential of molecular electronics in further applications. While many efforts have been devoted to this issue, in the absence of a chemical or electrochemical potential the open-shell character is lost when in contact with the metallic electrodes. Here, the organic 6-oxo-verdazyl radical, which is stable at ambient temperatures and atmosphere, has been functionalised by aurophilic 4-thioanisole groups at the 1,5-positions and fabricated into a molecular junction using the scanning tunnelling microscope break-junction technique. The verdazyl moiety retains open-shell character within the junction even at room temperature, and electrochemical gating permits in-situ reduction of the verdazyl to the closed-shell anionic state in a single-molecule transistor configuration. In addition, the bias-dependent alignment of the open-shell resonances with respect to the electrode Fermi levels gives rise to purely electronically-driven rectifying behaviour. The demonstration of a verdazyl-based molecular junction capable of integrating radical character, transistor-like switching behaviour, and rectification in a single molecular component under ambient conditions paves the way for further studies of the electronic, magnetic, and thermoelectric properties of open-shell species.

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Paving the way to single-molecule chemistry through molecular electronics

Physical Chemistry Chemical Physics ◽

10.1039/c9cp00264b ◽

2019 ◽

Vol 21 (19) ◽

pp. 9641-9650 ◽

Cited By ~ 1

Author(s):

Masateru Taniguchi

Keyword(s):

Molecular Electronics ◽

Single Molecule ◽

Single Molecules ◽

Single Molecule Junctions ◽

The Way

Since our understanding of single-molecule junctions, in which single molecules are connected between nanoelectrodes, has deepened, we have paved the way to single-molecule chemistry.

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Single-molecule junction spontaneously restored by DNA zipper

Nature Communications ◽

10.1038/s41467-021-25943-3 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Takanori Harashima ◽

Shintaro Fujii ◽

Yuki Jono ◽

Tsuyoshi Terakawa ◽

Noriyuki Kurita ◽

...

Keyword(s):

Molecular Electronics ◽

Single Molecule ◽

Structural Changes ◽

Electrical Measurements ◽

Static Structure ◽

Electrical Failure ◽

Molecular Length ◽

Single Molecule Junctions ◽

Molecule Junction ◽

Single Molecule Junction

AbstractThe electrical properties of DNA have been extensively investigated within the field of molecular electronics. Previous studies on this topic primarily focused on the transport phenomena in the static structure at thermodynamic equilibria. Consequently, the properties of higher-order structures of DNA and their structural changes associated with the design of single-molecule electronic devices have not been fully studied so far. This stems from the limitation that only extremely short DNA is available for electrical measurements, since the single-molecule conductance decreases sharply with the increase in the molecular length. Here, we report a DNA zipper configuration to form a single-molecule junction. The duplex is accommodated in a nanogap between metal electrodes in a configuration where the duplex is perpendicular to the nanogap axis. Electrical measurements reveal that the single-molecule junction of the 90-mer DNA zipper exhibits high conductance due to the delocalized π system. Moreover, we find an attractive self-restoring capability that the single-molecule junction can be repeatedly formed without full structural breakdown even after electrical failure. The DNA zipping strategy presented here provides a basis for novel designs of single-molecule junctions.

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Mechanically-Tunable Quantum Interference in Ferrocene-Based Single-Molecule Junctions

10.26434/chemrxiv.12252059 ◽

2020 ◽

Author(s):

María Camarasa-Gómez ◽

Daniel Hernangómez-Pérez ◽

Michael S. Inkpen ◽

Giacomo Lovat ◽

E-Dean Fung ◽

...

Keyword(s):

Single Molecule ◽

Quantum Interference ◽

Degrees Of Freedom ◽

Building Blocks ◽

Ferrocene Derivative ◽

Single Molecule Junctions ◽

Molecule Junction ◽

Single Molecule Junction ◽

The Impact ◽

D Orbitals

Ferrocenes are ubiquitous organometallic building blocks that comprise a Fe atom sandwiched between two cyclopentadienyl (Cp) rings that rotate freely at room temperature. Of widespread interest in fundamental studies and real-world applications, they have also attracted some interest as functional elements of molecular-scale devices. Here we investigate the impact of the configurational degrees of freedom of a ferrocene derivative on its single-molecule junction conductance. Measurements indicate that the conductance of the ferrocene derivative, which is suppressed by two orders of magnitude as compared to a fully conjugated analog, can be modulated by altering the junction configuration. Ab initio transport calculations show that the low conductance is a consequence of destructive quantum interference effects that arise from the hybridization of metal-based d-orbitals and the ligand-based π-system. By rotating the Cp rings, the hybridization, and thus the quantum interference, can be mechanically controlled, resulting in a conductance modulation that is seen experimentally.

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Charge Transfer Complexation Boosts Molecular Conductance Through Fermi Level Pinning

10.26434/chemrxiv.7110788 ◽

2018 ◽

Author(s):

Kun Wang ◽

Andrea Vezzoli ◽

Iain Grace ◽

Maeve McLaughlin ◽

Richard Nichols ◽

...

Keyword(s):

Charge Transfer ◽

Single Molecule ◽

Quantum Interference ◽

Transmission Function ◽

Scanning Tunneling ◽

Charge Transfer Complexes ◽

Tunneling Microscopy ◽

Quantum Interference Effect ◽

Single Molecule Junctions ◽

Charge Transfer Complexation

We have used scanning tunneling microscopy to create and study single molecule junctions with thioether-terminated oligothiophene molecules. We find that the conductance of these junctions increases upon formation of charge transfer complexes of the molecules with tetracyanoethene, and that the extent of the conductance increase is greater the longer is the oligothiophene, i.e. the lower is the conductance of the uncomplexed molecule in the junction. We use non-equilibrium Green's function transport calculations to explore the reasons for this theoretically, and find that new resonances appear in the transmission function, pinned close to the Fermi energy of the contacts, as a consequence of the charge transfer interaction. This is an example of a room temperature quantum interference effect, which in this case boosts junction conductance in contrast to earlier observations of QI that result in diminished conductance.

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Dissecting Contact Mechanics from Quantum Interference in Single-Molecule Junctions of Stilbene Derivatives

Nano Letters ◽

10.1021/nl2045815 ◽

2012 ◽

Vol 12 (3) ◽

pp. 1643-1647 ◽

Cited By ~ 122

Author(s):

Sriharsha V. Aradhya ◽

Jeffrey S. Meisner ◽

Markrete Krikorian ◽

Seokhoon Ahn ◽

Radha Parameswaran ◽

...

Keyword(s):

Contact Mechanics ◽

Single Molecule ◽

Quantum Interference ◽

Single Molecule Junctions ◽

Stilbene Derivatives

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Correction: Electronic conductance and thermopower of single-molecule junctions of oligo(phenyleneethynylene) derivatives

Nanoscale ◽

10.1039/d1nr90031e ◽

2021 ◽

Vol 13 (8) ◽

pp. 4685-4686

Author(s):

Hervé Dekkiche ◽

Andrea Gemma ◽

Fatemeh Tabatabaei ◽

Andrei S. Batsanov ◽

Thomas Niehaus ◽

...

Keyword(s):

Single Molecule ◽

Single Molecule Junctions ◽

Electronic Conductance

Correction for ‘Electronic conductance and thermopower of single-molecule junctions of oligo(phenyleneethynylene) derivatives’ by Hervé Dekkiche et al., Nanoscale, 2020, 12, 18908–18917, DOI: 10.1039/D0NR04413J.

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