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Un interruptor molecular quiróptico basado en foldamer que muestra una inversión completa del sentido helicoidal
Jae-min Suk1, Veluru Ramesh Naidu, Xinfang Liu
1Department of Chemistry, Yonsei University, Seoul, Korea.
Journal of the American Chemical Society
|August 19, 2011
Resumen
Los dímeros quirales de indolocarbazoles exhiben conformaciones helicoidales sensibles al disolvente. La unión de iones sulfato cambia reversiblemente el sentido helicoidal, confirmado por análisis espectroscópicos y cristalográficos.
Área de la Ciencia:
- Química supramolecular de las moléculas.
- Química orgánica es la química orgánica.
- La cristalografía química es una técnica de cristalografía química.
Sus antecedentes:
- Los dímeros quirales de indolocarbazoles poseen estructuras helicoidales únicas estabilizadas por enlaces de hidrógeno intramoleculares.
- Sus propiedades ópticas están influenciadas por cambios de conformación e interacciones con disolventes.
Objetivo del estudio:
- Para investigar el comportamiento conformacional y las propiedades ópticas de los dimeros quirales de indolocarbazoles.
- Para explorar el efecto de la unión de iones sulfato en el sentido helicoidal y la estereoquímica de estos dímeros.
Principales métodos:
- Espectroscopia de Resonancia Magnética Nuclear (RMN) (RMN) espectroscopía de resonancia magnética nuclear (RMN) espectroscopía de resonancia magnética nuclear (RMN) espectroscopía de resonancia magnética nuclear (RMN) espectroscopía de resonancia magnética nuclear (RMN) espectroscopía de resonancia magnética nuclear (RMN) espectroscopía de resonancia magnética nuclear (RMN) espectroscopía de resonancia magnética nuclear (RMN) espectroscopía de resonancia magnética nuclear
- Espectroscopia de dicroísmo circular (CD, por sus siglas en inglés)
- Mediciones de rotación óptica de las mediciones.
- Cristalografía de rayos X monocristalino de un solo cristal.
Principales resultados:
- Los dímeros adoptan una conformación helicoidal sensible a la polaridad del disolvente.
- La unión de iones sulfato induce un interruptor reversible en el sentido helicoidal, evidenciado por la inversión completa de los espectros de CD.
- Las estructuras de rayos X confirman el modo de unión y la estereoquímica absoluta de los complejos sulfatados, consistentes con los datos de la solución.
Conclusiones:
- Los dímeros quirales de indolocarbazoles son sistemas helicoidales dinámicos con conformaciones dependientes del disolvente.
- El ion sulfato actúa como un disparador específico para la conmutación reversible del sentido helicoidal.
- El estudio proporciona una comprensión detallada de las relaciones estructura-propiedad en estas moléculas quirales.
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