Design Considerations for Oligo(p-Phenyleneethynylene) Organic Radicals in Molecular Junctions

10.26434/chemrxiv.11950665 ◽

2020 ◽

Author(s):

Martin Sebastian Zöllner ◽

Rukan Nasri ◽

Haitao Zhang ◽

Carmen Herrmann

Keyword(s):

Spin Polarization ◽

Single Molecule ◽

Fermi Energy ◽

Organic Radicals ◽

Stable Radical ◽

Design Consideration ◽

Dispersion Interactions ◽

Electron Transmission ◽

Design Considerations ◽

Spin Delocalization

Spin polarization in the electron transmission of radicals is important for understanding single-molecule conductance experiments focusing on shot noise, Kondo properties or magnetoresistance. We study how stable radical substituents can affect such spin polarization when attached to oligo(p- phenyleneethynylene) (OPE) backbones. We find that it is not straightforward to translate the spin density on a stable radical substituent into spin-dependent transmission for the para-connected wires under study here, owing to increased steric interactions compared with meta-connected wires, and a resulting twisting of the radical substituent and OPE π systems. The most promising example is a t-butyl nitroxide substituent, which, despite little pronounced spin delocalization onto the backbone, yields a spin-dependent transmission feature which one might be able to shift towards the Fermi energy by additional substituents. We also find that for bulkier substituents, dispersion interactions with the substituent can lead to twisting of one of the outer OPE rings, reducing the overall conductance. As a further potential design consideration, attaching radicals via linkers might increase the possibilities for spin-dependent intermolecular and molecule-electrode interactions.

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Design Considerations for Oligo(p-Phenyleneethynylene) Organic Radicals in Molecular Junctions

10.26434/chemrxiv.11950665.v2 ◽

2020 ◽

Author(s):

Martin Sebastian Zöllner ◽

Rukan Nasri ◽

Haitao Zhang ◽

Carmen Herrmann

Keyword(s):

Spin Polarization ◽

Single Molecule ◽

Fermi Energy ◽

Organic Radicals ◽

Stable Radical ◽

Design Consideration ◽

Dispersion Interactions ◽

Electron Transmission ◽

Design Considerations ◽

Spin Delocalization

Spin polarization in the electron transmission of radicals is important for understanding single-molecule conductance experiments focusing on shot noise, Kondo properties or magnetoresistance. We study how stable radical substituents can affect such spin polarization when attached to oligo(p- phenyleneethynylene) (OPE) backbones. We find that it is not straightforward to translate the spin density on a stable radical substituent into spin-dependent transmission for the para-connected wires under study here, owing to increased steric interactions compared with meta-connected wires, and a resulting twisting of the radical substituent and OPE π systems. The most promising example is a t-butyl nitroxide substituent, which, despite little pronounced spin delocalization onto the backbone, yields a spin-dependent transmission feature which one might be able to shift towards the Fermi energy by additional substituents. We also find that for bulkier substituents, dispersion interactions with the substituent can lead to twisting of one of the outer OPE rings, reducing the overall conductance. As a further potential design consideration, attaching radicals via linkers might increase the possibilities for spin-dependent intermolecular and molecule-electrode interactions.

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Spin Polarized Transport through Structures Consist of the Ferromagnetic Semiconductor in Presence of a Inhomogeneous Magnetic Field

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.194-196.679 ◽

2011 ◽

Vol 194-196 ◽

pp. 679-682

Author(s):

Zahra Bamshad

Keyword(s):

Magnetic Field ◽

Spin Polarization ◽

Fermi Energy ◽

Magnetic Tunnel Junction ◽

Inhomogeneous Magnetic Field ◽

Spin Polarized ◽

Polarized Transport ◽

Dimensional Electron Gas ◽

Spin Electronic ◽

Spin Polarized Transport

The spin-polarized transport is investigated in a magnetic tunnel junction which consists of two ferromagnetic electrodes separated by a magnetic barrier and a nonmagnetic metallic spacer placed in distance above the two dimensional electron gas (2DEG) in presence of an inhomogeneous external modulated magnetic field and a perpendicular wave vector dependent effective potential. Based on the transfer matrix method and the nearly-free-electron approximation the dependence of the conductance and spin polarization on the Fermi energy of the electrons are studied theoretically the. strong oscillations with large amplitude investigated in spin polarization in terms of the Fermi energy due to the inhomogeneous magnetic field. The conductance in terms of the Fermi energy shows no oscillation in low energy but has a strong pick in middle region. this results may be useful for the development of spin electronic devices based on coherent transport, or may be used as a tunable spin-filter.

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Comment on the Interpretation of Hyperconjugation and Spin Delocalization in Organic Radicals

The Journal of Chemical Physics ◽

10.1063/1.1712355 ◽

1967 ◽

Vol 47 (8) ◽

pp. 3098-3100 ◽

Cited By ~ 16

Author(s):

J. P. Colpa ◽

E. de Boer ◽

D. Lazdins ◽

M. Karplus

Keyword(s):

Organic Radicals ◽

Spin Delocalization

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Spin Polarization Transfer from a Photogenerated Radical Ion Pair to a Stable Radical Controlled by Charge Recombination

The Journal of Physical Chemistry A ◽

10.1021/acs.jpca.7b03468 ◽

2017 ◽

Vol 121 (23) ◽

pp. 4455-4463 ◽

Cited By ~ 5

Author(s):

Noah E. Horwitz ◽

Brian T. Phelan ◽

Jordan N. Nelson ◽

Catherine M. Mauck ◽

Matthew D. Krzyaniak ◽

...

Keyword(s):

Spin Polarization ◽

Ion Pair ◽

Charge Recombination ◽

Polarization Transfer ◽

Stable Radical

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Design Considerations for Cold Storage Warehousing

ASME 1955 Citrus Engineering Conference ◽

10.1115/cec1955-0104 ◽

1955 ◽

Author(s):

James M. Fiske

Keyword(s):

Cold Storage ◽

Mechanical Equipment ◽

Design Consideration ◽

Careful Selection ◽

Professional Advice ◽

Design Considerations ◽

General Expansion ◽

Proper Analysis ◽

New Facilities

A general expansion of existing Cold Storage Warehousing or a program for construction of entirely new facilities calls for the proper analysis of design considerations and, most important, it requires that management properly establish the design consideration or search-out through study and professional advice, all fundamental considerations for analysis. The high cost per unit of warehouse space plus the fact that, once in use, the building and mechanical equipment cannot be readily and inexpensively repaired, changed, or added to makes careful selection and analysis of all considerations most important. Paper published with permission.

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Modulation of destructive quantum interference by bridge groups in truxene-based single-molecule junctions

Chemical Communications ◽

10.1039/d0cc07438a ◽

2021 ◽

Author(s):

Lin Wang ◽

Zhihao Zhao ◽

Digambar B. Shinde ◽

Zhiping Lai ◽

Dong Wang

Keyword(s):

Single Molecule ◽

Fermi Energy ◽

Interference Effect ◽

Quantum Interference ◽

Quantum Interference Effect ◽

Single Molecule Junctions

Nitrogen and carbonyl bridge substituents embedded in truxene derivatives enhance the single-molecule conductance prominently by alleviating the destructive quantum interference effect and pushing away the anti-resonance dip from the Fermi energy.

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Role of Intercalation on Electrical Properties of Nucleic Acids for use in Molecular Electronics

Nanoscale Horizons ◽

10.1039/d1nh00211b ◽

2021 ◽

Author(s):

Hashem Mohammad ◽

Busra Demir ◽

Caglanaz Akin ◽

Binquan Luan ◽

Joshua Hihath ◽

...

Keyword(s):

Electrical Properties ◽

Nucleic Acids ◽

Small Molecules ◽

Molecular Electronics ◽

Data Storage ◽

Single Molecule ◽

Essential Role ◽

Transmission Probability ◽

Electron Transmission

Intercalating ds-DNA/RNA with small molecules can play an essential role in controlling the electron transmission probability for molecular electronics applications such as biosensors, single-molecule transistors, and data storage. However, its...

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Design Consideration of Expander Heads for Vibration Systems: Part I: Natural Frequency Equations for Square, Constant Thickness Expander Heads

Journal of the IEST ◽

10.17764/jiet.2.34.2.c050g1845116wp17 ◽

1991 ◽

Vol 34 (2) ◽

pp. 45-55

Author(s):

Louie Lipp

Keyword(s):

Natural Frequency ◽

Test Time ◽

Constant Thickness ◽

Reliability Test ◽

Design Consideration ◽

Vibration Testing ◽

Design Considerations ◽

Simultaneous Testing ◽

Maximum Utilization ◽

Truncated Pyramid

Vibration testing, particularly when performed in reliability test chambers, is very costly. Design considerations for vibration expander heads that will accept several test specimens for simultaneous testing are discussed in this report. Well-designed expander heads will provide more meaningful results and reduce test time and costs through maximum utilization of test hardware. This article, the first of a three-part series, discusses natural frequency equations for square, constant thickness expander heads. Parts II and III will cover damping equations for square, constant thickness expander heads and the inverted truncated pyramid expander head. Complete derivations accompany each expander head equation.

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