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

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

π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds

1.2K
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...
1.2K
Basicity of Aromatic Amines01:18

Basicity of Aromatic Amines

7.2K
The basicity of aromatic amines is much weaker than that of aliphatic amines due to the involvement of the lone pair of electrons over the N atom in resonance with the aryl rings. Generally, the electron-donating ability of any substituents on the aryl ring of aromatic amines increases the basicity of the amine by increasing electron density, and hence the availability of lone pair on the nitrogen. On the other hand, electron-withdrawing functional groups on the aryl ring of amines decrease the...
7.2K
Paramagnetism01:30

Paramagnetism

2.5K
Paramagnets are materials with unpaired electrons that possess a finite magnetic moment. In the absence of a magnetic field, these moments are randomly oriented, and thus the net moment is zero. Under an external field, a torque acting on the moments tends to align them along the field's direction. However, the random thermal motion of electrons produces a torque opposite to the external field and tries to disorient the moments. These two competing effects align only a few moments along the...
2.5K
π Electron Effects on Chemical Shift: Overview01:27

π Electron Effects on Chemical Shift: Overview

1.1K
An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0,...
1.1K
Basicity of Heterocyclic Aromatic Amines01:25

Basicity of Heterocyclic Aromatic Amines

6.1K
Heterocyclic amines, where the N atom is a part of an alicyclic system, are similar in basicity to alkylamines. Interestingly, the heterocyclic amine having a nitrogen atom as part of an aromatic ring has much less basicity than its corresponding alicyclic counterpart. For this reason, as presented in Figure 1, piperidine (pKb = 2.8) is significantly more basic than pyridine (pKb = 8.8).
6.1K
Aromatic Hydrocarbon Anions: Structural Overview01:18

Aromatic Hydrocarbon Anions: Structural Overview

2.8K
Neutral hydrocarbons like cyclopentadiene with an odd number of carbon atoms and one intervening CH2 group in the ring are not aromatic. Cyclopentadiene with 4 π electrons does not satisfy the 4n + 2 π electron rule. Additionally, the intervening CH2 group is sp3 hybridized and lacks a vacant p orbital, thereby interrupting the overlap of p orbitals in a continuous manner and preventing the delocalization of π electrons throughout the ring.
Due to the absence of continuous...
2.8K

You might also read

Related Articles

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

Sort by
Same author

<sup>1</sup>H NMR chemical shift as an index of UV-vis absorption/emission maxima in aromatic dyes.

Physical chemistry chemical physics : PCCP·2026
Same author

Donor-Acceptor Pentacene Analogues With Near-Infrared Emission and Tunable Aromaticity.

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

Taming boroloborinines: toward photostable polycyclic antiaromatic hydrocarbons.

Chemical science·2026
Same author

Deciphering the molecular origin of the 19.3 eV electronic excitation energy of H<sub>3</sub><sup></sup>.

Chemical science·2026
Same author

Design of Carbon-Carbon Ylides.

Angewandte Chemie (International ed. in English)·2025
Same author

Indoloindolizines: The Complete Story of a Polycyclic Aromatic Scaffold from Theoretical Design to Organic Field-Effect Transistor Applications.

Journal of the American Chemical Society·2025

Related Experiment Video

Updated: Jul 15, 2025

Paramagnetic Relaxation Enhancement for Detecting and Characterizing Self-Associations of Intrinsically Disordered Proteins
07:24

Paramagnetic Relaxation Enhancement for Detecting and Characterizing Self-Associations of Intrinsically Disordered Proteins

Published on: September 23, 2021

1.8K

Magnetic Antiaromaticity─Paratropicity─Does Not Necessarily Imply Instability.

Cina Foroutan-Nejad1

  • 1Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.

The Journal of Organic Chemistry
|September 29, 2023
PubMed
Summary

Paratropic currents may not accurately indicate antiaromaticity in monocyclic hydrocarbons. Some radical ions exhibit strong paratropic currents yet gain stabilization through cyclic conjugation, challenging conventional interpretations of aromaticity.

More Related Videos

Controlling the Size, Shape and Stability of Supramolecular Polymers in Water
16:24

Controlling the Size, Shape and Stability of Supramolecular Polymers in Water

Published on: August 2, 2012

18.7K
Analysis of AtHIRD11 Intrinsic Disorder and Binding Towards Metal Ions by Capillary Gel Electrophoresis and Affinity Capillary Electrophoresis
07:54

Analysis of AtHIRD11 Intrinsic Disorder and Binding Towards Metal Ions by Capillary Gel Electrophoresis and Affinity Capillary Electrophoresis

Published on: August 22, 2018

6.0K

Related Experiment Videos

Last Updated: Jul 15, 2025

Paramagnetic Relaxation Enhancement for Detecting and Characterizing Self-Associations of Intrinsically Disordered Proteins
07:24

Paramagnetic Relaxation Enhancement for Detecting and Characterizing Self-Associations of Intrinsically Disordered Proteins

Published on: September 23, 2021

1.8K
Controlling the Size, Shape and Stability of Supramolecular Polymers in Water
16:24

Controlling the Size, Shape and Stability of Supramolecular Polymers in Water

Published on: August 2, 2012

18.7K
Analysis of AtHIRD11 Intrinsic Disorder and Binding Towards Metal Ions by Capillary Gel Electrophoresis and Affinity Capillary Electrophoresis
07:54

Analysis of AtHIRD11 Intrinsic Disorder and Binding Towards Metal Ions by Capillary Gel Electrophoresis and Affinity Capillary Electrophoresis

Published on: August 22, 2018

6.0K

Area of Science:

  • * Theoretical Chemistry
  • * Organic Chemistry
  • * Quantum Chemistry

Background:

  • * Magnetically induced ring currents are traditionally used to assess molecular aromaticity.
  • * Strong diatropic currents typically signify aromaticity (stabilization), while paratropic currents suggest antiaromaticity (destabilization).

Purpose of the Study:

  • * To critically evaluate the reliability of paratropic currents as a definitive measure of antiaromaticity in monocyclic hydrocarbons.
  • * To investigate the relationship between paratropic currents, radical ion formation, and cyclic conjugation in hydrocarbon systems.

Main Methods:

  • * Computational analysis of magnetically induced ring currents in monocyclic hydrocarbon radical ions.
  • * Comparison of cyclic conjugation stabilization energies between neutral hydrocarbons and their radical ion counterparts.

Main Results:

  • * Monocyclic hydrocarbon radical ions can exhibit significant paratropic currents.
  • * Despite strong paratropic currents, these radical ions often display enhanced stabilization due to cyclic conjugation.
  • * This stabilization suggests that paratropic currents alone may not be a sufficient indicator of antiaromaticity.

Conclusions:

  • * The validity of paratropic currents as a sole indicator of antiaromaticity in monocyclic hydrocarbons is questioned.
  • * Cyclic conjugation plays a crucial role in stabilizing hydrocarbon radical ions, even in the presence of strong paratropic currents.
  • * A nuanced understanding is required, considering both ring currents and conjugation effects for accurate aromaticity assessment.