Video Experimental Relacionado

Updated: Oct 14, 2025

Surface Functionalization of Metal-Organic Frameworks for Improved Moisture Resistance

Surface Functionalization of Metal-Organic Frameworks for Improved Moisture Resistance

Published on: September 5, 2018

Armazones orgánicos covalentes de imina basados en carbazoles químicamente estables con respuesta acidocrómica para

Leisan Gilmanova¹, Volodymyr Bon¹, Leonid Shupletsov¹

¹Chair of Inorganic Chemistry I, Technische Universität Dresden, Bergstraße 66, 01069 Dresden, Germany.

Journal of the American Chemical Society

|November 2, 2021

Resumen

Los nuevos marcos orgánicos covalentes (COF) presentan una excelente estabilidad y porosidad para un control eficiente de la humedad en interiores. Estos materiales muestran propiedades reversibles dependientes del pH y potencial para aplicaciones avanzadas de manejo de la humedad.

Área de la Ciencia:

Ciencias de los materiales
Química

Sus antecedentes:

Las estructuras orgánicas covalentes (COF) son polímeros porosos cristalinos con propiedades sintonizables.
El desarrollo de COF estables con una gran superficie es crucial para diversas aplicaciones.

Objetivo del estudio:

Síntesis y caracterización de nuevos COFs de imina isoreticulares, químicamente estables y bidimensionales (DUT-175 y DUT-176).
Investigar las propiedades estructurales, textuales y dependientes del pH de estos COF.
Evaluar su potencial para el control de la humedad en interiores.

Principales métodos:

Síntesis de COF mediante reacción de condensación de 4,4'-bis(9H-carbazol-9-il) bifenil tetraaldehído con fenildiamina y benzidina.
Determinación de la estructura mediante difracción de rayos X en polvo y microscopía electrónica de transmisión de alta resolución.
Evaluación de la porosidad mediante adsorción de gases y vapores.
Investigación de las propiedades dependientes del pH mediante espectroscopia UV-vis.

Principales resultados:

DUT-175 y DUT-176 se sintetizaron con éxito con estructuras de capas apiladas de AA y poros de canal hexagonales distorsionados.
Se lograron altas superficies Brunauer-Emmett-Teller (BET) (1071 m2 g−1 para el DUT-175 y 1062 m2 g−1 para el DUT-176).
Se observaron protonación y transferencia de carga reversibles dependientes del pH debido al sistema π conjugado y las unidades de carbazolos.
La excelente estabilidad y las isotermas sigmoidales de adsorción/desorción de vapor de agua indican su idoneidad para el control de la humedad.

Conclusiones:

Los COF sintetizados (DUT-175 y DUT-176) son altamente porosos, químicamente estables y exhiben un comportamiento único que responde al pH.
Sus notables propiedades de adsorción de vapor de agua y su estabilidad los convierten en candidatos prometedores para soluciones avanzadas de gestión de la humedad en interiores.

Más Videos Relacionados

Microfluidic-based Synthesis of Covalent Organic Frameworks COFs: A Tool for Continuous Production of COF Fibers and Direct Printing on a Surface

Microfluidic-based Synthesis of Covalent Organic Frameworks COFs: A Tool for Continuous Production of COF Fibers and Direct Printing on a Surface

Published on: July 10, 2017

Preparation of Hydrophobic Metal-Organic Frameworks via Plasma Enhanced Chemical Vapor Deposition of Perfluoroalkanes for the Removal of Ammonia

Preparation of Hydrophobic Metal-Organic Frameworks via Plasma Enhanced Chemical Vapor Deposition of Perfluoroalkanes for the Removal of Ammonia

Published on: October 10, 2013

Videos de Conceptos Relacionados

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).

Aldehydes and Ketones with Amines: Imine Formation Mechanism

Aldehydes and Ketones with Amines: Imine Formation Mechanism

Imine formation involves the addition of carbonyl compounds to a primary amine. It begins with the generation of carbinolamine through a series of steps involving an initial nucleophilic attack and then several proton transfer reactions. The second part includes the elimination of water, as a leaving group, to give the imine.
Imines are formed under mildly acidic conditions. A pH of 4.5 is ideal for the reaction.
If the pH is low or the solution is too acidic, the reaction slows down in the...

Aldehydes and Ketones with Amines: Imine and Enamine Formation Overview

Aldehydes and Ketones with Amines: Imine and Enamine Formation Overview

Primary amines react with carbonyl compounds—aldehydes and ketones—to generate imines. Imines consist of a C=N double bond and are named Schiff bases after its discoverer—the German chemist Hugo Schiff. On the other hand, secondary amines react with carbonyl compounds to give enamines. In enamines, the presence of a C=C double bond adjacent to the nitrogen atom leads to the delocalization of the lone pair.

Acid Halides to Carboxylic Acids: Hydrolysis

Acid Halides to Carboxylic Acids: Hydrolysis

Hydrolysis of acid halides is a nucleophilic acyl substitution reaction in which acid halides react with water to give carboxylic acids. The reaction occurs readily and does not require acid or a base catalyst.
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic...

Acid Halides to Amides: Aminolysis

Acid Halides to Amides: Aminolysis

Aminolysis is a nucleophilic acyl substitution reaction, where ammonia or amines act as nucleophiles to give the substitution product. Acid halides react with ammonia, primary amines, and secondary amines to yield primary, secondary, and tertiary amides, respectively.
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...

Multiple Halogenation of Methyl Ketones: Haloform Reaction

Multiple Halogenation of Methyl Ketones: Haloform Reaction

A method involving the transformation of methyl ketones to carboxylic acids using excess base and halogen is called the haloform reaction. It begins with the deprotonation of α hydrogen to form an enolate ion which reacts with the electrophilic halogen to give an α-halo ketone. The step continues until all the α protons are substituted to form a trihalomethyl ketone. The resulting molecule is unstable, and in the presence of a hydroxide base, it readily undergoes nucleophilic...