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

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
Frost Circles for Different Conjugated Systems01:18

Frost Circles for Different Conjugated Systems

2.8K
The inscribed polygon method is consistent with Hückel’s 4n + 2 rule and helps to learn whether the given cyclic compound is aromatic or not. The compound is stable and aromatic if every bonding molecular orbital (MO) is completely filled with a pair of electrons. However, if the non-bonding or antibonding orbitals are filled with electrons, the compound is unstable and not aromatic. Consider the Frost circle diagrams for cycloalkenes containing 4 to 8 carbons.
2.8K
Aromatic Hydrocarbon Cations: Structural Overview01:18

Aromatic Hydrocarbon Cations: Structural Overview

2.9K
Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
Removing one hydrogen from the intervening CH2 group...
2.9K
Criteria for Aromaticity and the Hückel 4n + 2 Rule01:20

Criteria for Aromaticity and the Hückel 4n + 2 Rule

10.9K
Like benzene, cyclobutadiene and cyclooctatetraene are cyclic compounds with alternate single and double bonds. However, their chemical behavior differs from benzene, as they are unstable and not aromatic. So, what are the structural characteristics of unsaturated compounds categorized as aromatic?  
For the first time, Eric Hückel, a German chemical physicist, derived a set of structural features for a compound to be classified as aromatic. This is now known as...
10.9K
Five-Membered Heterocyclic Aromatic Compounds: Overview01:13

Five-Membered Heterocyclic Aromatic Compounds: Overview

4.0K
Heterocyclic aromatic compounds are cyclic compounds that are aromatic and have one or more heteroatoms—atoms other than carbon, in the ring. Depending upon the number of atoms present in the ring, they can be either five or six-membered. Examples of five-membered heterocyclic aromatic compounds include pyrrole, furan, thiophene, and imidazole. Pyrrole consists of one nitrogen atom having one lone pair of electrons. Furan and thiophene have one oxygen and one sulfur heteroatom,...
4.0K
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

You might also read

Related Articles

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

Sort by
Same author

NRS2002-stratified body composition and laboratory characteristics in hospitalized cancer patients assessed by bioelectrical impedance analysis.

Frontiers in nutrition·2026
Same author

4,4'- and 2,4'-Bis(olympicenyl)s: Antiferromagnetically Coupled Diradicals with Twisted Conformations.

Organic letters·2026
Same author

Development and validation of a machine learning model integrating spectral computed tomography-derived three‑dimensional quantitative parameters and clinical features for predicting minimal extrathyroidal extension in papillary thyroid microcarcinoma.

Gland surgery·2026
Same author

Aethrene: A Stable Polycyclic Aromatic Hydrocarbon With a Triplet Ground State.

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

Natural history and clinical characteristics of pulmonary subsolid nodules in pediatric patients: a cohort study.

Quantitative imaging in medicine and surgery·2026
Same author

Molecular Nanocarbons with Diverse Connectivity and Topologies Enabled by Bismuth(III) Triflate-Mediated Benzannulation Reaction.

Accounts of chemical research·2026

Related Experiment Video

Updated: Jul 29, 2025

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
11:45

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles

Published on: August 22, 2018

8.5K

Aromaticity in Fully π-Conjugated Multicyclic Macrocycles.

Longbin Ren1, Yi Han1, Xudong Hou1

  • 1Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543 Singapore.

Journal of the American Chemical Society
|May 26, 2023
PubMed
Summary

Researchers synthesized novel multicyclic macrocycles (MMCs) by fusing thiophene rings. These MMCs exhibit unique electronic properties and complex aromaticity due to electronic coupling between fused rings.

More Related Videos

Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
09:35

Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units

Published on: September 18, 2016

11.6K
Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
10:17

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones

Published on: February 7, 2019

7.0K

Related Experiment Videos

Last Updated: Jul 29, 2025

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
11:45

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles

Published on: August 22, 2018

8.5K
Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
09:35

Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units

Published on: September 18, 2016

11.6K
Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
10:17

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones

Published on: February 7, 2019

7.0K

Area of Science:

  • Organic Chemistry
  • Materials Science
  • Theoretical Chemistry

Background:

  • Aromaticity research traditionally focuses on monocyclic and polycyclic aromatic hydrocarbons.
  • Fully π-conjugated multicyclic macrocycles (MMCs) offer unique electronic structures due to inter-ring electronic coupling.
  • Studies on MMCs are limited due to synthetic challenges.

Purpose of the Study:

  • To report the facile synthesis of novel fully π-conjugated MMCs.
  • To investigate the interplay between constitutional macrocycles in MMCs.
  • To explore the unique aromaticity and electronic properties of MMCs.

Main Methods:

  • Intramolecular and intermolecular Yamamoto coupling reactions were employed for synthesis.
  • A precursor (7) was designed for efficient MMC construction.
  • Monocyclic macrocycle (1TMC) synthesized as a reference compound.

Main Results:

  • Two MMCs (2TMC and 3TMC) and a monocyclic analogue (1TMC) were successfully synthesized.
  • X-ray crystallographic analysis, NMR, and theoretical calculations were performed.
  • Unique aromatic/antiaromatic character was observed due to macrocycle interplay.

Conclusions:

  • The study demonstrates a facile synthetic route to MMCs.
  • Interplay between constitutional macrocycles significantly influences electronic properties and aromaticity.
  • New insights into complex aromaticity in MMC systems were provided.