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Enredamiento de redes cuadradas en marcos orgánicos covalentes
Fangying Jin1, Ha L Nguyen1,2, Zhiye Zhong3
1Department of Chemistry, University of California-Berkeley, Kavli Energy Nanoscience Institute at UC Berkeley, and Berkeley Global Science Institute, Berkeley, California 94720, United States.
Journal of the American Chemical Society
|January 24, 2022
Resumen
Los investigadores sintetizaron las primeras estructuras orgánicas covalentes cuadradas 2D entrelazadas (COF). Este avance utiliza una nueva unidad de construcción SFTB, evitando el apilamiento π-π y permitiendo el entrelazamiento para el diseño de materiales avanzados.
Área de la Ciencia:
- Ciencias de los materiales
- Química supramolecular
- Química orgánica
Sus antecedentes:
- Las estructuras orgánicas covalentes (COF) son polímeros porosos cristalinos con propiedades sintonizables.
- Los COF 2D suelen exhibir un fuerte apilamiento π-π, lo que dificulta la formación de arquitecturas complejas.
- El desarrollo de estrategias para controlar la topología de COF y prevenir la agregación es crucial para aplicaciones avanzadas.
Objetivo del estudio:
- Para sintetizar nuevas estructuras de COF cuadrado enredado 2D.
- Investigar el papel de la unidad de construcción SFTB en la prevención del apilamiento de π-π y el enredo.
- Establecer nuevos principios de diseño para crear arquitecturas COF complejas.
Principales métodos:
- Síntesis de dos nuevos COF 2D, el COF-38 y el COF-39, mediante el uso de 4,4',4′′′-9,9'-spirobi[fluoreno]-2,2',7,7'-tetrail) -tetrabenzaldehído (SFTB) y p-fenilendiamina (PPA) o benzidina (BZD).
- Análisis de difracción de electrones de un solo cristal para determinar la estructura del COF-39.
- Utilizando un bloque de construcción SFTB tetraédrico distorsionado para controlar el conjunto del marco.
Principales resultados:
- Síntesis exitosa de COF-38 y COF-39, los primeros ejemplos de estructuras de COF cuadradas enredadas en 2D.
- Elucidación estructural de COF-39 que revela redes cuadradas 2D entrelazadas entre sí (topología sql).
- Demostrar que la unidad de construcción SFTB evita efectivamente el apilamiento π-π, facilitando la formación de redes entrelazadas.
Conclusiones:
- La unidad de construcción SFTB es clave para superar el apilamiento π-π en COFs 2D, lo que permite la formación de estructuras entrelazadas.
- Este trabajo introduce una nueva estrategia para el diseño de arquitecturas COF complejas e interconectadas.
- Los hallazgos avanzan significativamente en la comprensión y los principios de diseño de los marcos orgánicos covalentes.
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