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Control remoto de la quiralidad dinámica del Twistaceno
Si Tong Bao1, Haoyu Jiang1, Cedric Schaack1
1Department of Chemistry, Columbia University, New York, New York 10027, United States.
Journal of the American Chemical Society
|October 4, 2022
Resumen
Los investigadores desarrollaron un método para controlar la quiralidad axial en los twistacenos basados en perileno diimida (PDI) utilizando sustituyentes quirales. Esta quiralidad remota influye en la helicidad de las subunidades flexibles, con sustituyentes y disolventes que impactan las señales de CD.
Área de la Ciencia:
- Química orgánica
- Química supramolecular
- Materiales quirópticos
Sus antecedentes:
- Los derivados de perileno diimida (PDI) son ampliamente estudiados por sus propiedades optoelectrónicas.
- El control de la quiralidad axial en moléculas orgánicas complejas es crucial para el desarrollo de materiales funcionales avanzados.
- Los twistacenos, con sus estructuras helicoidales inherentes, ofrecen propiedades fotofísicas únicas.
Objetivo del estudio:
- Establecer un método fiable para la manipulación de la quiralidad axial dinámica en twistacenes basados en PDI.
- Investigar la influencia de los sustituyentes quirales en la posición de la imida para inducir la helicidad.
- Comprender el papel de los sustituyentes y el entorno del disolvente en el control de las propiedades quirópticas.
Principales métodos:
- Síntesis de twistacenos basados en PDI con sustituyentes quirales.
- Absorción UV y espectroscopia de dicroísmo circular (CD).
- Cristalografía de rayos X y cálculos de la teoría funcional de la densidad dependiente del tiempo (TDDFT).
Principales resultados:
- Los sustituyentes quirales en la posición de imida inducen y controlan con éxito la helicidad en los twistacenos basados en PDI.
- La quiralidad remota dicta efectivamente la conformación helicoidal de las subunidades flexibles [4] de heliceno.
- Tanto los sustituyentes quirales como la polaridad del disolvente afectan significativamente el signo y la intensidad de las señales de CD.
- Los cálculos de DFT indican que las interacciones estéricas de los grupos quirales son clave para inducir la helicidad preferida.
Conclusiones:
- Se ha demostrado una estrategia robusta para controlar la quiralidad axial dinámica en las fases de torsión PDI.
- Los hallazgos proporcionan información sobre las relaciones estructura-propiedad que rigen la inducción de la helicidad en sistemas quirales flexibles.
- Este trabajo abre caminos para el diseño de nuevos materiales optoelectrónicos quirales con propiedades sintonizables.
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