Related Experiment Video
Updated: Jun 14, 2026
09:35
Preparation of a Corannulene-functionalized Hexahelicene by Copper(I)-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
Synthesis and stability of soluble hexacenes
Balaji Purushothaman1, Sean R Parkin, John E Anthony
1Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, USA.
Organic Letters
|April 9, 2010
Summary
New silylethyne-substituted hexacenes show "butterfly" dimerization as their main decomposition pathway, not photooxidation. Stability is improved by modifying molecular structure to prevent close contact and control dimerization.
Area of Science:
- Organic Chemistry
- Materials Science
- Photochemistry
Background:
- Hexacenes are polycyclic aromatic hydrocarbons with potential applications in organic electronics.
- Understanding their stability and degradation pathways is crucial for device development.
- Silylethyne substitution offers a route to tune electronic and structural properties.
Purpose of the Study:
- To synthesize novel silylethyne-substituted hexacene derivatives.
- To investigate their solubility, stability, and pi-stacking behavior.
- To elucidate the dominant decomposition mechanisms and explore strategies for stability enhancement.
Main Methods:
- Synthesis of silylethyne-substituted hexacene derivatives.
- Solubility and stability testing under various conditions.
- Spectroscopic and crystallographic analysis to study pi-stacking and decomposition pathways.
- Computational modeling to understand dimerization mechanisms.
Main Results:
- Silylethyne-substituted hexacenes were successfully synthesized.
- "Butterfly" dimerization was identified as the primary decomposition pathway, surpassing photooxidation.
- Molecular functionalization was shown to enhance stability by hindering close intermolecular contacts.
- Solid-state arrangement engineering allows for control over dimerization regioselectivity.
Conclusions:
- The dominant degradation pathway for these hexacene derivatives is intramolecular "butterfly" dimerization.
- Strategic functionalization and control of solid-state packing are effective methods to enhance the stability of hexacene-based materials.
- These findings provide valuable insights for designing stable organic electronic materials.
Related Concept Videos
02:30Stability of Substituted Cyclohexanes
This lesson discusses the stability of substituted cyclohexanes with a focus on energies of various conformers and the effect of 1,3-diaxial interactions.
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
01:28Stability 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.
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.
01:26Thermal 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.
02:33Stereoisomerism of Cyclic Compounds
In this lesson, we delve into the role of ring conformation and its stability, which determines the spatial arrangement and, consequently, the molecular symmetry and stereoisomerism of cyclic compounds. 1,2-Dimethylcyclohexane is used as a case study to evaluate the possible number of stereoisomers. Here, given the multiple (n = 2) chiral centers, there are 2n = 4 possible configurations that lack a plane of symmetry, as the ring skeleton exists in a non-planar chair conformation. In addition,...
02:02Chair Conformation of Cyclohexane
The chair conformation is the most stable form of cyclohexane due to the absence of angle and torsional strain. The absence of angle strain is a result of cyclohexane’s bond angle being very close to the ideal tetrahedral bond angle of 109.5° in its chair conformer. Similarly, the torsional strain is also absent owing to the perfectly staggered arrangement of bonds.
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this staggered...
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this staggered...
01:18Aromatic 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...
Removing one hydrogen from the intervening CH2 group with both...