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Control de la separación de cargas por isomerización estructural de imina en marcos orgánicos covalentes con

Daniel H Streater¹, Eric R Kennehan², Denan Wang³

¹Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, United States.

Journal of the American Chemical Society

|February 8, 2024

Resumen

Las estructuras orgánicas covalentes bidimensionales isoméricas (COF) con enlaces imanes invertidos muestran una reducción de CO2 fotocatalítica distinta. El isómero imino delantero COF convierte eficientemente el CO2, a diferencia del isómero imino inverso, debido a la transferencia de carga dirigida.

Área de la Ciencia:

Ciencias de los materiales
Fotocatálisis
Química orgánica

Sus antecedentes:

Los marcos orgánicos covalentes bidimensionales (COF) son prometedores para la conversión de energía solar.
El control de las propiedades de los COF es crucial para optimizar el rendimiento fotocatalítico.

Objetivo del estudio:

Investigar el impacto de la estructura isomérica en las propiedades de los COF y en la reducción fotocatalítica del CO2.
Comprender el papel de la orientación del enlace imino en la dinámica de transferencia de carga.

Principales métodos:

Síntesis de dos COF estructuralmente isoméricos con direcciones de enlace imino invertidas.
Incorporación de un catalizador molecular de renio (Re) en la columna vertebral del COF.
Utilizando espectroscopia ultrarrápida y cálculos teóricos para estudiar las propiedades fotofísicas.

Principales resultados:

Los COF isoméricos mostraron diferencias significativas en las propiedades físicas y fotofísicas.
El isómero imino delantero de COF (f-COF) mostró una reducción fotocatalítica eficiente de CO2.
El isómero imino inverso de COF (r-COF) mostró una actividad fotocatalítica mínima.
La direccionalidad de transferencia de carga intramolecular, influenciada por la polaridad de la imina, fue identificada como el factor clave.

Conclusiones:

La química del vinculante, específicamente la orientación del enlace imino, influye críticamente en el comportamiento fotofísico y fotocatalítico del COF.
La direccionalidad selectiva de la carga es esencial para el diseño de fotocatalizadores eficientes de reducción de CO2.
Este trabajo proporciona información sobre la adaptación de los FOC para aplicaciones específicas de energía solar.

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