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 Experiment Videos

Diamagnetic and paramagnetic ring currents in expanded porphyrins.

Erich Steiner1, Patrick W Fowler

  • 1Department of Chemistry, School of Biological and Chemical Sciences, University of Exeter, Stocker Road, Exeter, UKEX4 4QD.

Organic & Biomolecular Chemistry
|January 23, 2004
PubMed
Summary

Sapphyrin exhibits aromaticity with a diatropic ring current, while orangarin shows antiaromaticity with a paratropic current. Frontier orbital analysis explains these opposite magnetic behaviors in expanded porphyrins.

Related Concept Videos

You might also read

Related Articles

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

Sort by
Same author

Random walks and the electronic structure of graphene.

The Journal of chemical physics·2026
Same author

Perturbing Pentalene: Aromaticity and Antiaromaticity in a Non-Alternant Polycyclic Aromatic Hydrocarbon and BN-Heteroanalogues.

Chemphyschem : a European journal of chemical physics and physical chemistry·2025
Same author

Ring Currents in the Clar Goblet Calculated Using Configurational State Averaging.

The journal of physical chemistry. A·2024
Same author

Tuning (Anti)Aromaticity: Variations on the [8]-Circulene Framework.

Chemphyschem : a European journal of chemical physics and physical chemistry·2024
Same author

<i>Per</i>iodoannulenes: A Generalized Annulene-within-an-Annulene Paradigm for Combined σ and π Ring Currents.

The journal of physical chemistry. A·2021
Same author

A Correlated Source-Sink-Potential Model Consistent with the Meir-Wingreen Formula.

The journal of physical chemistry. A·2020

Area of Science:

  • Computational Chemistry
  • Quantum Chemistry
  • Organic Chemistry

Background:

  • Expanded porphyrins like sapphyrin and orangarin are macrocyclic compounds with unique electronic properties.
  • Understanding their magnetic and electronic behavior is crucial for developing new materials and understanding fundamental chemical principles.

Purpose of the Study:

  • To compute and analyze ipsocentric current density maps for sapphyrin and orangarin.
  • To investigate the origins of global macrocyclic ring currents and their relationship to aromaticity and antiaromaticity.
  • To correlate electronic structure, specifically frontier orbitals, with observed magnetic properties.

Main Methods:

  • Calculations performed at the coupled Hartree-Fock (CHF) level of theory.
  • Utilized the 6-31G** basis set for computational accuracy.

Related Experiment Videos

  • Employed B3LYP geometries for planar C(2v) expanded porphyrins.

    • Main Results:

    • Sapphyrin displays a dominant diatropic ring current (22[small pi] system), indicating aromaticity.
    • Orangarin exhibits a dominant paratropic ring current (20[small pi] system) around an inner pathway, indicating antiaromaticity.
    • Analysis revealed that frontier orbital topology, energy, and symmetry dictate the macrocyclic ring current.

    Conclusions:

    • The electronic structure and symmetry of frontier orbitals are key determinants of ring current direction and magnitude in expanded porphyrins.
    • Sapphyrin's aromaticity is analogous to benzene, driven by 4-electron diamagnetism.
    • Orangarin's antiaromaticity is analogous to planarized cyclooctatetraene, driven by 2-electron paramagnetism.