Video Experimental Relacionado

Updated: Mar 17, 2026

Preparation of 6-aminocyclohepta-2,4-dien-1-one Derivatives via Tricarbonyltroponeiron

Preparation of 6-aminocyclohepta-2,4-dien-1-one Derivatives via Tricarbonyltroponeiron

Published on: August 12, 2019

Formación de anillo de cicloheptatrieno de tipo Scholl alrededor de un núcleo de tribenzotriquinaceno: hacia grafeno

Ho-Wang Ip¹, Chun-Fai Ng¹, Hak-Fun Chow¹

¹Department of Chemistry, Institute of Molecular Functional Materials, and The Center of Novel Functional Molecules, The Chinese University of Hong Kong , Shatin, Hong Kong.

Journal of the American Chemical Society

|August 2, 2016

Resumen

Los investigadores sintetizaron una molécula única en forma de sombrero mágico con un núcleo de tribenzotriquinaceno (TBTQ). Este nuevo intermediario de nanographene ofrece el potencial para la construcción molecular avanzada.

Área de la Ciencia:

Química orgánica
Ciencias de los materiales
Nanotecnología

Sus antecedentes:

Los hidrocarburos aromáticos policíclicos (HAP) son cruciales en la ciencia de los materiales.
El desarrollo de nanografenes no planas con estructuras definidas es un desafío.
El tribenzotriquinaceno (TBTQ) ofrece un núcleo único para nuevas arquitecturas moleculares.

Objetivo del estudio:

Para sintetizar un nuevo compuesto aromático policíclico no plano con un núcleo TBTQ.
Explorar la utilidad de este compuesto como un intermediario clave para la construcción de nanografenos.
Caracterizar la estructura y las propiedades de la molécula sintetizada.

Principales métodos:

Síntesis de un derivado del TBTQ (compuesto 5).
Utilizando tres reacciones de tipo Scholl para la formación de anillos de cicloheptatrieno.
Caracterización mediante espectroscopia de resonancia magnética nuclear (RMN) y cristalografía de rayos X.

Principales resultados:

Preparación exitosa de una molécula en forma de sombrero mágico (compuesto 6) con un núcleo de TBTQ y un cinturón de hexafenileno.
La aclaración estructural confirmó la arquitectura no plana única.
El compuesto sirve como un intermediario prometedor para la construcción de moléculas complejas de nanografeno.

Conclusiones:

Se sintetizó un nuevo precursor de nanografeno en forma de sombrero mágico basado en el núcleo TBTQ.
La estrategia sintética que involucra múltiples reacciones de Scholl es efectiva para crear sistemas policíclicos complejos.
Este trabajo abre caminos para diseñar y construir estructuras avanzadas de nanografeno no planas.

Más Videos Relacionados

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates

Published on: February 15, 2016

Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units

Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units

Published on: September 18, 2016

Videos de Conceptos Relacionados

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.

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.

Woodward–Hoffmann Selection Rules and Microscopic Reversibility

Woodward–Hoffmann Selection Rules and Microscopic Reversibility

Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for...

Conformations of Cyclohexane

Conformations of Cyclohexane

Cyclohexane does not exist in a planar form due to the high angle and torsional strain it would experience in the planar structure. Instead, it adopts non-planar chair and boat conformations.
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal...

Chair Conformation of Cyclohexane

Chair 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...