Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Radical Reactivity: Overview01:11

Radical Reactivity: Overview

3.0K
Radicals, the highly reactive species, gain stability by undergoing three different reactions. The first reaction involves a radical-radical coupling, in which a radical combines with another radical, forming a spin‐paired molecule. The second reaction is between a radical and a spin‐paired molecule, generating a new radical and a new spin‐paired molecule. The third reaction is radical decomposition in a unimolecular reaction, forming a new radical and a spin‐paired...
3.0K
Radical Formation: Addition00:47

Radical Formation: Addition

2.4K
Radicals can be formed by adding a radical to a spin-paired molecule. This is typically observed with unsaturated species, where the addition of a radical across the π bond leads to the production of a new radical by dissolving the π bond. For example, the addition of a Br radical to an alkene yields a carbon-centered radical.
Similar to charge conservation in chemical reactions, spin conservation is implicit for radical reactions. Accordingly, the product formed must possess an...
2.4K
Radical Reactivity: Steric Effects01:10

Radical Reactivity: Steric Effects

2.7K
The presence of electron-donating, electron-withdrawing, or conjugating groups adjacent to a radical center, imparts electronic stabilization to the radicals. Examples of such electronically-stabilized radicals are triphenylmethyl, tetramethylpiperidine‐N‐oxide, and 2,2‐diphenyl‐1‐picrylhydrazyl. These radicals are remarkably stable and are known as persistent radicals. Some of the persistent radicals can even be isolated and purified.
Along with electronic...
2.7K
Radical Reactivity: Concentration Effects01:20

Radical Reactivity: Concentration Effects

1.9K
In a radical reaction, the concentration of starting materials governs the selectivity of a radical. For example, the reaction between an alkyl halide and an alkene, in the presence of tin hydride and AIBN, begins with the generation of a tin radical. The generated radical then abstracts halogen from the alkyl halide, producing an alkyl radical. This alkyl radical can either react with tin hydride, yielding an alkane, or add to an alkene, generating a nitrile-stabilized radical, eventually...
1.9K
Radical Formation: Overview01:03

Radical Formation: Overview

2.7K
A bond can be broken either by heterolytic bond cleavage to form ions or homolytic bond cleavage to yield radicals. A fishhook arrow is used to represent the motion of a single electron in homolytic bond cleavage. There are two main sources from which radicals can be formed:
Radicals from spin-paired molecules:
Radicals can be obtained from spin-paired molecules either by homolysis or electron transfer. While two radicals are formed in the former, an electron is added in the...
2.7K
Radical Reactivity: Intramolecular vs Intermolecular01:33

Radical Reactivity: Intramolecular vs Intermolecular

2.3K
Radical reactions can occur either intermolecularly or intramolecularly. In an intermolecular radical reaction, a nucleophilic radical adds to an electrophilic alkene or vice versa. In such reactions, the radical and generally the alkene, which is also called the radical trap, are two different molecules. Additionally, for such intermolecular reactions to occur, the radical trap must be active, present in an excess concentration, and the radical starting material must have a weak...
2.3K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Habitual physical activity and sarcopenia: a systematic review and meta-analysis of prospective cohort studies.

Journal of global health·2026
Same author

Single-Molecule Memristor Realizing Synaptic Plasticity for Neuromorphic Applications.

Angewandte Chemie (International ed. in English)·2026
Same author

Reliability and Consistency Analysis of Multiple Instruments for Scoliosis Screening in Adolescent Males: A Comparative Study of Instrument Accuracy.

Studies in health technology and informatics·2026
Same author

Circulating multiple metals and mortality after myocardial infarction: incremental value beyond GRACE.

American journal of preventive cardiology·2026
Same author

A venetoclax-cytarabine-based induction regimen incorporating a translation inhibitor for adult patients with de novo acute myeloid leukemia.

Cancer·2026
Same author

Controlling Photochromism of Donor-Acceptor Stenhouse Adducts on Micro-Dot Arrays Beyond Human-Eyes Resolution for Dynamic Light Encryption.

Advanced science (Weinheim, Baden-Wurttemberg, Germany)·2026

Related Experiment Video

Updated: Apr 17, 2026

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
10:44

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals

Published on: April 19, 2019

11.9K

Radical-to-radical push-pull effect enhances single-molecule conductance in asymmetric diradicals.

Dacheng Dai1, Qian Zhan1, Tianfang Shi1

  • 1School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC) Chengdu 611731 People's Republic of China zhengyonghao@uestc.edu.cn xdliu@uestc.edu.cn wangds@uestc.edu.cn.

Chemical Science
|April 16, 2026
PubMed
Summary
This summary is machine-generated.

Asymmetric diradicals with push-pull electron spin effects show increased conductance. This tuning of single-molecule conductance is linked to intramolecular radical-radical coupling and new electronic states.

More Related Videos

Exploring the Radical Nature of a Carbon Surface by Electron Paramagnetic Resonance and a Calibrated Gas Flow
10:34

Exploring the Radical Nature of a Carbon Surface by Electron Paramagnetic Resonance and a Calibrated Gas Flow

Published on: April 24, 2014

11.4K
Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst
06:49

Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst

Published on: April 22, 2016

12.5K

Related Experiment Videos

Last Updated: Apr 17, 2026

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
10:44

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals

Published on: April 19, 2019

11.9K
Exploring the Radical Nature of a Carbon Surface by Electron Paramagnetic Resonance and a Calibrated Gas Flow
10:34

Exploring the Radical Nature of a Carbon Surface by Electron Paramagnetic Resonance and a Calibrated Gas Flow

Published on: April 24, 2014

11.4K
Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst
06:49

Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst

Published on: April 22, 2016

12.5K

Area of Science:

  • Molecular electronics
  • Quantum chemistry
  • Materials science

Background:

  • Asymmetry in diradicals creates unique push-pull electron spin effects.
  • Diradical substructures can be integrated into molecular wires for electronic studies.

Purpose of the Study:

  • To investigate the conductance of asymmetric diradicals using single-molecule junction techniques.
  • To establish relationships between intramolecular radical-radical coupling and single-molecule conductance.

Main Methods:

  • Utilized scanning tunneling microscope break junction technique to measure conductance.
  • Synthesized asymmetric diradicals appended to a bisphenyl-thiophene segment linked to electrodes.
  • Analyzed conductance in both non-radical and diradical states.

Main Results:

  • Observed increased conductance in diradicals compared to their non-radical counterparts.
  • Attributed conductance enhancement to new intragap states and an additional conjugation channel via hypervalent sulfur.
  • Found conductance reduction with increased donor-acceptor moiety size due to competing electronic forms.

Conclusions:

  • Single-molecule junction techniques enable the study of diradical conductance tuning.
  • Push-pull electron spin effects in asymmetric diradicals significantly modulate molecular conductance.
  • Molecular orbital and valence bond theories explain the observed conductance changes.