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Dinámico o no dinámico? La trayectoria helicoidal en los nanotubos de hexabenzocoroneno está sesgada por un auxiliar

Wei Zhang¹, Wusong Jin, Takanori Fukushima

¹RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.

Journal of the American Chemical Society

|December 21, 2012

Resumen

Los complejos de platino quiral agregados a los derivados de hexa-peri-hexabenzocoroneno (HBC) inducen el ensamblaje selectivo de sentido de tornillo en nanotubos y nanobobinas ópticamente activas. Los nanotubos libres de metales conservan la quiralidad después de la eliminación del colgante, lo que demuestra estructuras helicoidales robustas.

Área de la Ciencia:

Química supramolecular de las moléculas.
Ciencia de los materiales Ciencia de los materiales.
Química orgánica es la química orgánica.

Sus antecedentes:

Los derivados de hexa-peri-hexabenzocoroneno (HBC) son conocidos por sus propiedades de autoensamblaje.
Los metaciclos quirales pueden influir en el ensamblaje de moléculas orgánicas.
El control de la quiralidad helicoidal en nanoestructuras autoensambladas es un desafío significativo.

Objetivo del estudio:

Para investigar el ensamblaje selectivo de sentido de tornillo de los derivados de HBC funcionalizados con complejos quirales de platino.
Para explorar la formación de nanotubos y nano bobinas ópticamente activas.
Para determinar la estabilidad y la retención de quiralidad de las estructuras autoensambladas después de la eliminación del metal.

Principales métodos:

Autoensamblaje inducido por difusión de vapor de los derivados de HBC con metaciclos quirales (BINAP) utilizando éter o metanol.
Caracterización de nanoestructuras mediante el uso de microscopía electrónica de barrido (SEM).
Análisis de quiralidad utilizando espectroscopia de dicroísmo circular (CD) y evaluación del exceso diastereomérico.

Principales resultados:

El ensamblaje selectivo de sentido de tornillo produjo nanotubos ópticamente activos (NT (((Py) ((((R) -Pt)) y NT (((Py) ((([(S) -Pt)) con una quiralidad helicoidal predecible (M o P).
El uso de metanol resultó en la formación de nano bobinas con un 60% de exceso diastereomérico (relación 80:20).
Los nanotubos libres de metales (NT ((Py)) obtenidos después de la eliminación de Pt mantuvieron la actividad óptica y la integridad quiral al calentarse.

Conclusiones:

Los colgantes de platino quiral controlan efectivamente la quiralidad helicoidal de los nanotubos HBC autoensamblados.
Las estructuras helicoidales autoensambladas exhiben una estabilidad notable y mantienen la quiralidad incluso después de la eliminación del complejo metálico.
Este trabajo proporciona una vía para crear nanoestructuras quirales con propiedades helicoidales sintonizables.

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