Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Stability of Conjugated Dienes

Stability of Conjugated Dienes

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.

Aromatic Hydrocarbon Cations: Structural Overview

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...

Thermal and Photochemical Electrocyclic Reactions: Overview

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.

Structure of Conjugated Dienes

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...

π Molecular Orbitals of 1,3-Butadiene

π Molecular Orbitals of 1,3-Butadiene

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...

Thermal Electrocyclic Reactions: Stereochemistry

Thermal Electrocyclic Reactions: Stereochemistry

The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.

You might also read

Related Articles

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

Sort by

Same author

Electrochemical and kinetic analysis for electrode overpotential of LaGaO<sub>3</sub>-based cells in reversible operation.

Physical chemistry chemical physics : PCCP·2026

Same author

High-Efficiency and Stability Phenothiazine-Based D-(A'-π-A)<sub>2</sub> Sensitized Photocatalytic Hydrogen Evolution Under Visible Light.

ChemSusChem·2026

Same author

High-efficiency and stable deep-blue iridium phosphorescent OLEDs with enhanced charge transfer dynamics.

Light, science & applications·2026

Same author

Lemniscular BODIPY Array of Expanded Porphyrinoids: A π-Conjugated Macrocycle Exhibiting Bright Near-Infrared Circularly Polarized Luminescence.

Journal of the American Chemical Society·2026

Same author

Amplified Spontaneous Emission Enhancement in FAPbI<sub>3</sub> Nanocrystal Films via PMMA and Mechanical Tunability on Flexible PET.

ACS applied materials & interfaces·2026

Same author

Unveiling the emission mechanism in analog-doped carbazole-based organic afterglow materials.

Nature communications·2026

Search research articles

Related Experiment Video

Updated: Nov 8, 2025

Low Pressure Vapor-assisted Solution Process for Tunable Band Gap Pinhole-free Methylammonium Lead Halide Perovskite Films

Low Pressure Vapor-assisted Solution Process for Tunable Band Gap Pinhole-free Methylammonium Lead Halide Perovskite Films

Published on: September 8, 2017

Heptacene: Synthesis and Its Hole-Transfer Property in Stable Thin Films.

Takaaki Miyazaki^1,2, Motonori Watanabe³, Toshinori Matsushima^3,4,5

¹Department of Chemistry, Faculty of Science, Fukuoka University, Fukuoka, 814-0180, Japan.

Chemistry (Weinheim an Der Bergstrasse, Germany)

|April 27, 2021

Summary

Stable heptacene was synthesized and demonstrated high thermal stability. This research explores heptacene

Keywords:

heptacene hydrocarbons p-type organic field-effect transistors synthetic methods thermal conversion

More Related Videos

Preparation of Carbon Nanosheets at Room Temperature

Preparation of Carbon Nanosheets at Room Temperature

Published on: March 8, 2016

Chemical Synthesis of Porous Barium Titanate Thin Film and Thermal Stabilization of Ferroelectric Phase by Porosity-Induced Strain

Chemical Synthesis of Porous Barium Titanate Thin Film and Thermal Stabilization of Ferroelectric Phase by Porosity-Induced Strain

Published on: March 27, 2018

Related Experiment Videos

Last Updated: Nov 8, 2025

Low Pressure Vapor-assisted Solution Process for Tunable Band Gap Pinhole-free Methylammonium Lead Halide Perovskite Films

Low Pressure Vapor-assisted Solution Process for Tunable Band Gap Pinhole-free Methylammonium Lead Halide Perovskite Films

Published on: September 8, 2017

Preparation of Carbon Nanosheets at Room Temperature

Preparation of Carbon Nanosheets at Room Temperature

Published on: March 8, 2016

Chemical Synthesis of Porous Barium Titanate Thin Film and Thermal Stabilization of Ferroelectric Phase by Porosity-Induced Strain

Chemical Synthesis of Porous Barium Titanate Thin Film and Thermal Stabilization of Ferroelectric Phase by Porosity-Induced Strain

Published on: March 27, 2018

Area of Science:

Organic electronics
Materials science
Solid-state chemistry

Background:

Heptacene is a polycyclic aromatic hydrocarbon with potential applications in organic electronics.
Previous synthesis routes for heptacene were challenging, limiting its investigation.
Stable heptacene is crucial for developing high-performance organic electronic devices.

Purpose of the Study:

To synthesize a stable form of heptacene.
To evaluate heptacene's thermal stability.
To assess heptacene's potential as a p-type semiconductor in organic field-effect transistors (OFETs).

Main Methods:

Synthesis of heptacene from a monoketone precursor in nine steps.
Quantitative conversion of the precursor to heptacene via thermal treatment at 202°C.
Fabrication of top-contact OFET devices using vacuum deposition of heptacene.

Main Results:

Heptacene was successfully synthesized with a 10% overall yield.
Heptacene exhibited excellent thermal stability, remaining unchanged for two months.
The fabricated OFET devices demonstrated a maximum hole mobility of 2.2 cm²/Vs.

Conclusions:

This study reports the first effective device fabrication and charge carrier property examination of stable heptacene.
Heptacene shows promise as a p-type semiconductor material for organic field-effect transistors.
The high thermal stability of heptacene is advantageous for practical device applications.