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

Electron Paramagnetic Resonance (EPR) Spectroscopy: Organic Radicals01:17

Electron Paramagnetic Resonance (EPR) Spectroscopy: Organic Radicals

3.6K
Ideally, an unpaired electron shows a single peak in the EPR spectrum due to the transition between the two spin energy states. However, coupling interactions can occur between the spins of the unpaired electron and any neighboring spin-active nuclei. This hyperfine coupling results in hyperfine splitting, where the EPR signal is split into multiplets. The signals split into 2nI + 1 peaks, where n is the number of equivalent nuclei and I is the nuclear spin. These splitting patterns provide...
3.6K
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: Overview01:11

Radical Reactivity: Overview

2.8K
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...
2.8K
Radical Formation: Addition00:47

Radical Formation: Addition

2.3K
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...
2.3K
Radical Reactivity: Steric Effects01:10

Radical Reactivity: Steric Effects

2.6K
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...
2.6K
π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds01:14

π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds

1.9K
In aromatic compounds, such as benzene, the circulation of (4n + 2) π-electrons sets up a diamagnetic or diatropic ring current around the perimeter of the molecule. This current induces a magnetic field that opposes the external field inside the ring and reinforces it on the outside. The protons in benzene are deshielded and exhibit high chemical shifts in the range 6.5–8.5 ppm. The shielding effect at the center of the ring is evident in complex aromatic molecules, such as...
1.9K

You might also read

Related Articles

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

Sort by
Same author

In Search of Entangled Singlet Pure Diradicals.

The journal of physical chemistry. A·2024
Same author

Ordering Effect of Charge-Charge Repulsion in Doped Antiferromagnetic Lattices: A Coupled Cluster Study.

The journal of physical chemistry. A·2024
Same author

Mapping the Slow Stabilization of End States with Length along a Laterally Extended Graphene Nanoribbon.

The journal of physical chemistry letters·2024
Same author

On Entangled Singlet Pure Diradicals.

The journal of physical chemistry. A·2024
Same author

From complete to selected model spaces in determinant-based multi-reference second-order perturbation treatments.

The Journal of chemical physics·2023
Same author

Difficulty of the evaluation of the barrier height of an open-shell transition state between closed shell minima: The case of small C<sub>4n</sub> rings.

The Journal of chemical physics·2022

Related Experiment Video

Updated: Feb 21, 2026

Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds
11:44

Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds

Published on: October 18, 2018

27.7K

Spreading out spin density in polyphenalenyl radicals.

Georges Trinquier1, Jean-Paul Malrieu

  • 1Laboratoire de Chimie et Physique Quantiques (CNRS-UMR5626), IRSAMC, Université Paul-Sabatier (Toulouse III), 31062 Toulouse Cedex, France. georges.trinquier@irsamc.ups-tlse.fr.

Physical Chemistry Chemical Physics : PCCP
|October 6, 2017
PubMed
Summary

Polycondensed phenalenyl units can create highly-delocalized spin distributions in radicals. Geometric arrangement influences spin uniformity, with implications for organic electronics and spintronics.

More Related Videos

Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels
11:19

Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels

Published on: July 4, 2016

11.1K
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

11.3K

Related Experiment Videos

Last Updated: Feb 21, 2026

Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds
11:44

Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds

Published on: October 18, 2018

27.7K
Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels
11:19

Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels

Published on: July 4, 2016

11.1K
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

11.3K

Area of Science:

  • Organic Chemistry
  • Materials Science
  • Quantum Chemistry

Background:

  • Topological arguments suggest polycondensed phenalenyl units can yield delocalized spin distributions.
  • Understanding the geometric factors governing spin delocalization is crucial for material design.

Purpose of the Study:

  • To investigate the geometric conditions required for highly-delocalized spin distributions in phenalenyl-based radicals.
  • To quantify the extent of spin delocalization across conjugated skeletons.
  • To assess the thermodynamic stability of these delocalized radical systems.

Main Methods:

  • Utilized Unrestricted Density Functional Theory (UDFT) calculations.
  • Examined various fused phenalene unit arrangements, up to 19 units.
  • Calculated spin distributions and assessed thermodynamic stability of radicals and their ionic derivatives.

Main Results:

  • Confirmed significant spin-density spreading over entire conjugated skeletons in polycondensed phenalenyl systems.
  • Observed that spin distribution uniformity depends on the compacity of the arrangement; linear arrangements show less delocalization.
  • Demonstrated a correlation between the degree of spin delocalization and the thermodynamic stability of the radicals.

Conclusions:

  • Geometrically constrained phenalenyl arrangements facilitate extensive spin delocalization.
  • Delocalized radicals are thermodynamically stable and their ionic counterparts (monocations and monoanions) are expected to exhibit delocalized charges.
  • These findings suggest potential applications in organic design, electronic devices, and spintronics.