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 Cations: Structural Overview01:18

Aromatic Hydrocarbon Cations: Structural Overview

3.4K
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...
3.4K
π Molecular Orbitals of 1,3-Butadiene01:24

π Molecular Orbitals of 1,3-Butadiene

10.6K
Conjugated dienes have lower heats of hydrogenation than cumulated and isolated dienes, making them more stable. The enhanced stabilization of conjugated systems can be understood from their π molecular orbitals.
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...
10.6K
Aromatic Hydrocarbon Anions: Structural Overview01:18

Aromatic Hydrocarbon Anions: Structural Overview

3.3K
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...
3.3K
Criteria for Aromaticity and the Hückel 4n + 2 Rule01:20

Criteria for Aromaticity and the Hückel 4n + 2 Rule

12.2K
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 Hückel’s rule or the 4n +...
12.2K
Stability of Conjugated Dienes01:28

Stability of Conjugated Dienes

3.9K
Introduction
A comparison of the enthalpies of hydrogenation of dienes reveals that conjugated dienes release less heat on hydrogenation, rendering them more stable than their nonconjugated analogs.
3.9K
Structure of Conjugated Dienes01:16

Structure of Conjugated Dienes

6.3K
Introduction
Conjugated dienes are compounds characterized by the presence of alternating double and single bonds. In a conjugated system like 1,3-butadiene, the unhybridized 2p orbital on each carbon overlaps continuously, allowing the π electrons to be delocalized across the entire molecule. In contrast, this type of overlap does not occur in cumulated and isolated dienes, such as 2,3-pentadiene and 1,4-pentadiene, respectively. Instead, the π electrons remain localized between the double...
6.3K

You might also read

Related Articles

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

Sort by
Same author

Sustainable energy harvesting <i>via</i> a scalable Janus photonic metamaterial for thermoelectric generation.

Materials horizons·2026
Same author

Ultralow chromium doping enables all-PbSe thermoelectric cooling.

Science (New York, N.Y.)·2026
Same author

Maternal hypertensive disorders in East Asia, 1990-2023: incidence, deaths, DALYs and maternal mortality in women aged 20-54 years using GBD 2023.

Hypertension in pregnancy·2026
Same author

The relationship between proactive health literacy and lifestyle behaviors among residents in a region of China.

Frontiers in public health·2026
Same author

Ion-sensitive in-situ gel loaded with rebamipide micelles for the treatment of diabetic keratopathy.

Colloids and surfaces. B, Biointerfaces·2026
Same author

A machine learning model for optimizing treatment of patients with poorly controlled type 2 diabetes.

Communications medicine·2026

Related Experiment Video

Updated: Nov 22, 2025

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

11.8K

Double π-Extended Undecabenzo[7]helicene.

Ying Chen1, Chaojun Lin1, Zhixing Luo1

  • 1School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, China.

Angewandte Chemie (International Ed. in English)
|January 7, 2021
PubMed
Summary
This summary is machine-generated.

Researchers synthesized a novel, large chiral nanographene, undecabenzo[7]helicene, exhibiting exceptional light absorption and record electronic circular dichroism. This discovery opens new avenues for advanced materials science.

Keywords:
PAHchiral nanographenechiroptical propertyextended conjugationhelicene

More Related Videos

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of &#945;-Imino &#947;-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

7.1K
Retropinacol/Cross-pinacol Coupling Reactions - A Catalytic Access to 1,2-Unsymmetrical Diols
10:12

Retropinacol/Cross-pinacol Coupling Reactions - A Catalytic Access to 1,2-Unsymmetrical Diols

Published on: April 4, 2014

13.3K

Related Experiment Videos

Last Updated: Nov 22, 2025

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

11.8K
Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of &#945;-Imino &#947;-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

7.1K
Retropinacol/Cross-pinacol Coupling Reactions - A Catalytic Access to 1,2-Unsymmetrical Diols
10:12

Retropinacol/Cross-pinacol Coupling Reactions - A Catalytic Access to 1,2-Unsymmetrical Diols

Published on: April 4, 2014

13.3K

Area of Science:

  • Organic Chemistry
  • Materials Science
  • Nanotechnology

Background:

  • Helicenes are polycyclic aromatic hydrocarbons with a chiral, helical structure.
  • Large, extended π-systems in nanographenes offer unique electronic and optical properties.
  • Developing novel nanographenes with enhanced photophysical characteristics is crucial for advanced applications.

Purpose of the Study:

  • To synthesize and characterize the first double π-extended undecabenzo[7]helicene.
  • To investigate the unusual photophysical properties of this novel nanographene.
  • To compare the properties of the double π-extended helicene with its mono-extended analogue.

Main Methods:

  • Chemical synthesis of the undecabenzo[7]helicene.
  • Single crystal X-ray diffraction for molecular structure confirmation.
  • Spectroscopic analysis (UV-Vis absorption and electronic circular dichroism) to determine photophysical properties.

Main Results:

  • Successfully synthesized and confirmed the structure of the double π-extended undecabenzo[7]helicene (1).
  • Compound 1 exhibits broad light absorption from UV to near-infrared with an extremely high molar absorption coefficient (844,000 M⁻¹cm⁻¹ at 573 nm).
  • Optically pure 1 displays a record high electronic circular dichroism intensity (|Δϵ|=1375 M⁻¹cm⁻¹ at 430 nm) for polycyclic aromatic hydrocarbons.

Conclusions:

  • The synthesized double π-extended undecabenzo[7]helicene possesses unique and superior photophysical properties compared to related compounds.
  • These findings highlight the potential of large chiral nanographenes for applications requiring strong light-matter interactions.
  • The study provides a new platform for exploring structure-property relationships in extended π-conjugated systems.