Video Experimental Relacionado

Updated: Mar 10, 2026

Preparation of Enantiopure Non-Activated Aziridines and Synthesis of Biemamide B, D, and epiallo-Isomuscarine

Preparation of Enantiopure Non-Activated Aziridines and Synthesis of Biemamide B, D, and epiallo-Isomuscarine

Published on: June 13, 2022

Radicales aminiles neutros derivados de los tintes de azoimidazolio

Léonard Y M Eymann¹, Alexander G Tskhovrebov¹, Andrzej Sienkiewicz²

¹Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.

Journal of the American Chemical Society

|December 10, 2016

Resumen

Los investigadores sintetizaron radicales aminílicos neutrales estables a través de la reducción de potasio de los tintes de azoimidazolio. Tanto los monorrádicos como los birrádicos mostraron una alta estabilidad, con una densidad de espín localizada en los átomos de nitrógeno.

Área de la Ciencia:

Química orgánica
La Química Radical
Ciencias de los materiales

Sus antecedentes:

Los radicales aminilo son radicales orgánicos centrados en el nitrógeno.
Los compuestos azo son precursores versátiles para la generación de radicales.
Los radicales estables son valiosos en varias aplicaciones químicas.

Objetivo del estudio:

Para sintetizar y caracterizar una nueva clase de radicales aminílicos neutros.
Investigar la estructura electrónica y la estabilidad de estos radicales.
Para explorar la formación de monorrádicos y birrádicos.

Principales métodos:

Reducción de los colorantes de azoimidazolio mediante el uso de potasio.
Caracterización estructural mediante difracción de rayos X o técnicas similares.
Análisis espectroscópico (por ejemplo, EPR, UV-Vis) y modelado computacional.

Principales resultados:

Síntesis exitosa de los monorrádicos de aminilo neutro y un birrádico.
Los datos estructurales y espectroscópicos indican la densidad de espín localizada en los átomos de nitrógeno.
Alta estabilidad tanto de los monorrádicos como de los birrádicos en solución y en estado sólido.

Conclusiones:

Se ha desarrollado una nueva clase de radicales aminílicos neutrales estables.
La estrategia sintética proporciona acceso tanto a los monoradicales como a los birradicales.
Estos radicales estables tienen potencial para aplicaciones en química y ciencias de los materiales.

Más Videos Relacionados

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles

Published on: August 22, 2018

Preparation of Contiguous Bisaziridines for Regioselective Ring-Opening Reactions

Preparation of Contiguous Bisaziridines for Regioselective Ring-Opening Reactions

Published on: July 28, 2022

Videos de Conceptos Relacionados

Aryldiazonium Salts to Azo Dyes: Diazo Coupling

Aryldiazonium Salts to Azo Dyes: Diazo Coupling

The reaction of weakly electrophilic aryldiazonium (also called arenediazonium) salts with highly activated aromatic compounds leads to the formation of products with an —N=N— link, called an azo linkage. This reaction, presented in Figure 1, is known as diazo coupling and occurs without the loss of the nitrogen atoms of the aryldiazonium salt. Highly activated aromatic compounds such as phenols or arylamines favor the diazo coupling reaction. The coupling generally occurs at the para...

1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism

1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO₂ Mechanism

Nitrous acid is a relatively weak and unstable acid prepared in situ by the reaction of sodium nitrite and cold, dilute hydrochloric acid. In an acidic solution, the nitrous acid undergoes protonation when it loses water to form a nitrosonium ion—an electrophile. Nitrous acid reacts with primary amines to give diazonium salts. The reaction is called diazotization of primary amines.

Preparation of 1° Amines: Azide Synthesis

Preparation of 1° Amines: Azide Synthesis

Direct alkylation of ammonia produces polyalkylated amines, along with a quaternary ammonium salt. To exclusively prepare primary amines, the azide synthesis method can be used.
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...

Basicity of Heterocyclic Aromatic Amines

Basicity of Heterocyclic Aromatic Amines

Heterocyclic amines, where the N atom is a part of an alicyclic system, are similar in basicity to alkylamines. Interestingly, the heterocyclic amine having a nitrogen atom as part of an aromatic ring has much less basicity than its corresponding alicyclic counterpart. For this reason, as presented in Figure 1, piperidine (pKb = 2.8) is significantly more basic than pyridine (pKb = 8.8).

Diazonium Group Substitution: –OH and –H

Diazonium Group Substitution: –OH and –H

Nitrous acid, a weak acid, is prepared in situ via the reaction of sodium nitrite with a strong acid under cold conditions. This nitrous acid prepared in situ reacts with primary arylamines to form arenediazonium salts. Such reactions are known as diazotization reactions. As shown in Figure 1, the formation of arenediazonium salts begins with the decomposition of nitrous acid in an acidic solution to give nitrosonium ions.

Basicity of Aromatic Amines

Basicity of Aromatic Amines

The basicity of aromatic amines is much weaker than that of aliphatic amines due to the involvement of the lone pair of electrons over the N atom in resonance with the aryl rings. Generally, the electron-donating ability of any substituents on the aryl ring of aromatic amines increases the basicity of the amine by increasing electron density, and hence the availability of lone pair on the nitrogen. On the other hand, electron-withdrawing functional groups on the aryl ring of amines decrease the...