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Las estructuras orgánicas covalentes bidimensionales monocristalinas vinculadas a la imina separan el benceno y el

Anusree Natraj¹, Woojung Ji¹, Junjie Xin²

¹Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.

Journal of the American Chemical Society

|October 20, 2022

Resumen

Los investigadores sintetizaron marcos orgánicos covalentes bidimensionales de un solo cristal de alta calidad (2D COF) rápidamente bajo condiciones ambientales. Estos avanzados COF 2D demuestran un rendimiento superior en las separaciones moleculares, destacando la importancia de la estructura cristalina.

Área de la Ciencia:

Ciencias de los materiales
Nanotecnología
Ingeniería Química

Sus antecedentes:

Los marcos orgánicos covalentes bidimensionales (2D COF) son materiales porosos en capas, generalmente sintetizados como sólidos policristalinos con pequeños dominios cristalinos.
Los métodos de síntesis existentes a menudo requieren condiciones duras y dan como resultado materiales con una perfección cristalina limitada, lo que dificulta su potencial de aplicación.
El control preciso de la estructura y la cristalinidad es crucial para desbloquear las propiedades únicas de los COF 2D.

Objetivo del estudio:

Desarrollar un método rápido y escalable para sintetizar cristales únicos de COF 2D vinculados a iminas.
Investigar las características estructurales de estos cristales simples de COF 2D sintetizados.
Evaluar el rendimiento de los cristales simples de COF en 2D en aplicaciones de separación molecular.

Principales métodos:

Polimerización de COFs 2D en suspensión ligados a iminas para obtener cristales simples facetados.
Caracterización mediante microscopía electrónica de transmisión de alta resolución (HRTEM) y difracción de electrones de rotación continua (cRED).
Incorporación de cristales simples de COF en las columnas de cromatografía de gases para estudios de separación.

Principales resultados:

Síntesis exitosa de cristales únicos de COF 2D rómbico (TAPPy-PDA) y hexagonal (TAPB-DMPDA) vinculados a la imina en cuestión de minutos en condiciones ambientales.
HRTEM y cRED confirmaron la naturaleza monocristalina en capas de los cristales de COF en el plano ab.
Los COFs 2D monocristalinos exhibieron retención selectiva de ciclohexano sobre el benceno en las separaciones de GC, con TAPPy-PDA superando a TAPB-DMPDA; las contrapartes policristalinas mostraron poca o ninguna separación.

Conclusiones:

Este estudio presenta la primera síntesis rápida a presión ambiente de cristales únicos de COF 2D vinculados a la imina.
El rendimiento superior de los COF monocristalinos en las separaciones moleculares subraya el papel crítico de la calidad del material y la perfección cristalina.
Los FOC 2D de alta calidad son muy prometedores para las tecnologías avanzadas de separación.

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