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

Nomenclature of Alkynes02:39

Nomenclature of Alkynes

Alkynes are unsaturated hydrocarbons characterized by the presence of carbon-carbon triple bonds and have a general formula CnH2n-2. The nomenclature of alkynes follows a set of rules similar to alkanes and alkenes; however, alkynes bear the suffix "-yne" instead of "-ane" or "-ene." There are two approaches to naming alkynes:
Structure and Physical Properties of Alkynes02:37

Structure and Physical Properties of Alkynes

Introduction:
In nature, compounds containing both carbon and hydrogen are known as "hydrocarbons". Aliphatic hydrocarbons are compounds whose molecules contain saturated single bonds (i.e., alkanes) or unsaturated double or triple bonds. Alkenes contain carbon–carbon double bonds and have a structural formula CnH2n. Unsaturated hydrocarbons containing carbon–carbon triple bonds are called "alkynes" and are structurally represented by the formula CnH2n-2.
The simplest alkyne is ethyne, or...
Aromatic Hydrocarbon Anions: Structural Overview01:18

Aromatic Hydrocarbon Anions: Structural Overview

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 overlap of p...
Acidity of 1-Alkynes02:42

Acidity of 1-Alkynes


The acidic strength of hydrocarbons follows the order: Alkynes > Alkenes > Alkanes. The strength of an acid is commonly expressed in units of pKa — the lower the pKa, the stronger the acid. Among the hydrocarbons, terminal alkynes have lower pKa values and are, therefore, more acidic. For example, the pKa values for ethane, ethene, and acetylene are 51, 44, and 25, respectively, as shown here.
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction01:16

[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction

The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.
Aromatic Hydrocarbon Cations: Structural Overview01:18

Aromatic Hydrocarbon Cations: Structural Overview

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 with both...

You might also read

Related Articles

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

Sort by
Same author

Separation of Molecular Magnets via HPLC with EPR Online Monitoring.

Analytical chemistry·2026
Same author

Solution-synthesized stable triaza[4]triangulene triradical with a quartet ground state.

Nature communications·2026
Same author

Conformation-Variable [7]Annulenyl Radicals.

Chemistry (Weinheim an der Bergstrasse, Germany)·2026
Same author

A Stable Triindenobenzotrithiophene Triradical with Equilateral Ferromagnetic Spin Coupling.

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

Reassortment risk of clade 2.3.4.4b H5N1 with avian H9N2 and human H3N2 and H1N1 influenza A viruses.

Science bulletin·2025
Same author

Smartwatch-based ventilatory assessment for COPD screening: A diagnostic accuracy study.

Digital health·2025

Related Experiment Video

Updated: Jun 8, 2026

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
09:22

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives

Published on: February 7, 2017

Arylene ethynylene macrocycles with intramolecular π-π stacking.

Shusen Chen1, Qifan Yan, Tian Li

  • 1Beijing National Laboratory for Molecular Sciences, Department of Applied Chemistry, College of Chemistry, Peking University, Beijing 100871, China.

Organic Letters
|September 30, 2010
PubMed
Summary

New macrocycles with aromatic units were synthesized. These molecules show intramolecular stacking and unique liquid-crystal properties due to their discotic shape.

More Related Videos

Preparation of a Corannulene-functionalized Hexahelicene by Copper(I)-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
09:35

Preparation of a Corannulene-functionalized Hexahelicene by Copper(I)-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units

Published on: September 18, 2016

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

Related Experiment Videos

Last Updated: Jun 8, 2026

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
09:22

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives

Published on: February 7, 2017

Preparation of a Corannulene-functionalized Hexahelicene by Copper(I)-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
09:35

Preparation of a Corannulene-functionalized Hexahelicene by Copper(I)-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units

Published on: September 18, 2016

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

Area of Science:

  • Organic Chemistry
  • Supramolecular Chemistry
  • Materials Science

Background:

  • Macrocyclic compounds offer unique structural and electronic properties.
  • Aromatic interactions play a crucial role in molecular self-assembly.
  • Discotic molecules are known to exhibit liquid crystalline behavior.

Purpose of the Study:

  • To synthesize novel arylene ethynylene macrocycles incorporating anthrylene and naphthylene units.
  • To investigate the intramolecular interactions within these macrocycles.
  • To explore the potential liquid crystalline properties of the synthesized compounds.

Main Methods:

  • Synthesis of arylene ethynylene macrocycles.
  • Nuclear Magnetic Resonance (NMR) spectroscopy to analyze molecular structure and interactions.
  • Density Functional Theory (DFT) calculations to model and support structural findings.

Main Results:

  • Successful synthesis of anthrylene and naphthylene-containing macrocycles.
  • Observation of significant upfield shifts in NMR spectra, indicating intramolecular π-π stacking.
  • DFT calculations confirmed the proposed intramolecular stacking motif.
  • The anthrylene-containing macrocycle exhibited a liquid-crystal phase.

Conclusions:

  • Arylene ethynylene macrocycles can adopt conformations with intramolecular π-π stacking.
  • The discotic shape of the anthrylene macrocycle is responsible for its liquid crystalline behavior.
  • These findings contribute to the design of novel functional organic materials.