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Los nanógrafos multicapa helicoidales extendidos con propiedades quirópticas dependientes de las capas
Wenhui Niu1,2, Yubin Fu1,2, Zhen-Lin Qiu2
1Max Planck Institute of Microstructure Physics, Weinberg 2, Halle 06120, Germany.
Journal of the American Chemical Society
|December 4, 2023
Resumen
Los investigadores desarrollaron nuevos nanógrafos helicoidales multicapa (NG) con propiedades quirópticas sintonizables. Estos nanografenes extendidos muestran potencial como emisores avanzados de luminiscencia polarizada circular (CPL).
Área de la Ciencia:
- Química orgánica
- Ciencias de los materiales
- Nanotecnología
Sus antecedentes:
- Los nanógrafos helicoidales (NG) poseen una quiralidad intrínseca y propiedades quirópticas únicas.
- La síntesis eficiente de NGs helicoidales extendidos y multicapa y sus propiedades dependientes de la capa están poco exploradas.
Objetivo del estudio:
- Desarrollar una estrategia sintética modular para nuevos NG helicoidales multicapa.
- Investigar las propiedades fotofísicas y quirópticas dependientes de las capas de estos NG.
Principales métodos:
- Síntesis modular mediante reacciones consecutivas de Diels-Alder y ciclodehidrogenación regioselectiva.
- Caracterización mediante análisis de rayos X de un solo cristal o de difracción de electrones.
- Mediciones de las propiedades fotofísicas y quirópticas.
Principales resultados:
- Síntesis exitosa de NG helicoidales de dos, tres y cuatro capas con sistemas π alargados y espina dorsal helicoidal rígida.
- Las propiedades fotofísicas (absorción, coeficiente de extinción molar, rendimiento cuántico de fluorescencia) son ajustables con el número de capas.
- La quiralidad estable de las subunidades de heliceno [7] incorporadas permite la resolución quiral y los estudios quirópticos dependientes de la capa.
- Alto dicroísmo circular y respuesta de luminiscencia polarizada circular (CPL) con un brillo CPL excepcional (hasta 168 M-1 cm-1).
Conclusiones:
- La síntesis modular permite el acceso a nuevas NG helicoidales multicapa.
- La ingeniería de capas influye significativamente en las características fotofísicas y quirópticas.
- Estos NG helicoidales son candidatos prometedores para los emisores CPL de alto rendimiento.
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