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

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...
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 of Conjugated Dienes01:16

Structure of Conjugated Dienes

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...
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 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...
Thermal and Photochemical Electrocyclic Reactions: Overview01:26

Thermal and Photochemical Electrocyclic Reactions: Overview

Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.

You might also read

Related Articles

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

Sort by
Same author

Quantum Chemistry for Solids Made Simple on the Clifford Torus.

Physical review letters·2026
Same author

Charge localization in diatomic ions investigated with a new dipole moment driven approach. Test for Ne2+ and (ArNe).

The Journal of chemical physics·2025
Same author

Tests of Artificial Neural Network-Based Diabatization Approaches on Simple 1D Models.

Journal of chemical theory and computation·2025
Same author

The Emergence of the Hexagonal Lattice in Two-Dimensional Wigner Fragments.

The journal of physical chemistry letters·2024
Same author

Electronic Structure of Pentagonal Carbon Nanocones: An ab Initio Study.

The journal of physical chemistry. A·2023
Same author

Rotational Transitions in the N<sub>2</sub> <sup>+</sup> Ion Induced by Collisions with Helium Atoms in Cold Helium Plasmas. A Quasiclassical Trajectory Study.

Chemphyschem : a European journal of chemical physics and physical chemistry·2023

Related Experiment Video

Updated: May 17, 2026

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

A theoretical study of closed polyacene structures.

Muammar El Khatib1, Stefano Evangelisti, Thierry Leininger

  • 1Laboratoire de Chimie et Physique Quantiques-IRSAMC, Université de Toulouse et CNRS, 118, Route de Narbonne, F-31062 Toulouse Cedex, France.

Physical Chemistry Chemical Physics : PCCP
|October 20, 2012
PubMed
Summary

Investigating polyacene stripes revealed that 60° angles create unique electronic states. This finding, observed in hexagons, rhombuses, and triangles, aligns with the Ovchinnikov rule for spin multiplicity.

More Related Videos

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

Microscopic Visualization of Porous Nanographenes Synthesized through a Combination of Solution and On-Surface Chemistry
08:18

Microscopic Visualization of Porous Nanographenes Synthesized through a Combination of Solution and On-Surface Chemistry

Published on: March 4, 2021

Related Experiment Videos

Last Updated: May 17, 2026

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

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

Microscopic Visualization of Porous Nanographenes Synthesized through a Combination of Solution and On-Surface Chemistry
08:18

Microscopic Visualization of Porous Nanographenes Synthesized through a Combination of Solution and On-Surface Chemistry

Published on: March 4, 2021

Area of Science:

  • Computational Chemistry
  • Materials Science
  • Quantum Chemistry

Background:

  • Planar molecular structures, such as polyacene stripes, exhibit unique electronic properties.
  • Understanding the electronic structure of these systems is crucial for designing novel materials.

Purpose of the Study:

  • To investigate the electronic structure of planar polyacene stripes.
  • To explore the impact of specific molecular geometries, particularly 60° angles, on electronic states.
  • To analyze the spin multiplicity of resulting quasi-flat molecular structures.

Main Methods:

  • Employed tight-binding and ab initio computational methods.
  • Utilized Configuration Interaction Self-Consistent Field (CAS-SCF) and Multi-Reference Perturbation Theory (MR-PT) for ab initio calculations.
  • Examined convex polygons: hexagons, rhombuses, and triangles with unique side lengths.

Main Results:

  • Identified the formation of singly-occupied molecular orbitals due to 60° angles in the molecular skeleton.
  • Observed the emergence of quasi-degenerate electronic states resulting from the combination of these orbitals.
  • Demonstrated systematic agreement between the spin multiplicity of these structures and the Ovchinnikov rule.

Conclusions:

  • The presence of 60° angles is a key factor in determining the electronic properties of polyacene stripes.
  • Advanced computational methods are necessary for accurately describing the electronic structure of these systems.
  • The findings provide a theoretical basis for understanding and predicting the magnetic properties of polyacene-based materials.