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Películas ópticas quirales basadas en huéspedes cromóforos achirales
Paola Rizzo1, Tommaso Montefusco, Gaetano Guerra
1Dipartimento di Chimica and INSTM Research Unit, Università degli Studi di Salerno, via Ponte don Melillo, 84084 Fisciano, Salerno, Italy.
Journal of the American Chemical Society
|May 24, 2011
Resumen
Los investigadores desarrollaron películas ópticas quirales utilizando polímeros y huéspedes achirales. La cristalización del poliestireno sindiotáctico (s-PS) con una molécula quiral temporal induce una estructura quiral estable en la película final.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Química de Polímeros La Química de Polímeros es la química de los polímeros.
- Física óptica Física de la óptica Física de la óptica Física de la óptica Física de la óptica Física de la óptica Física de la óptica
Sus antecedentes:
- Los polímeros y cromóforos achirales generalmente no exhiben propiedades ópticas quirales.
- La creación de materiales con respuestas ópticas quirales sintonizables es un desafío significativo en la ciencia de los materiales.
- El poliestireno sindiotáctico (s-PS) es un polímero bien establecido y comercialmente disponible.
Objetivo del estudio:
- Desarrollar películas con intensas respuestas ópticas quirales a través de un amplio rango espectral (UV-visible a infrarrojo).
- Investigar un nuevo método para inducir la quiralidad en materiales basados en polímeros.
- Explorar la formación y las propiedades de las fases cocristalinas polímero-anfitrión/cromóforo-invitado.
Principales métodos:
- Inducir la cristalización del poliestireno sindiotáctico amorfo (s-PS) utilizando una molécula huésped no racémica.
- Intercambio del huésped temporal no racémica con un huésped cromóforo achiral.
- Caracterizando las películas cocristalinas resultantes del polímero-anfitrión/cromóforo-invitado por sus propiedades ópticas y estructura.
Principales resultados:
- Las películas de polímero huésped aciral y las películas de cromóforo huésped exhibieron intensas respuestas ópticas quirales tanto en las regiones visibles IR como UV.
- Se produjeron con éxito películas de diferentes espesores, desde la nanoescala hasta la macroscópica.
- El comportamiento óptico quiral se remonta a la morfología no racémica de las regiones cristalinas inducidas por un invitado quiral temporal.
- La fase cocristalina de s-PS/azuleno adoptó una forma monoclinica de δ-clatrato con hélices iguales a la izquierda y a la derecha.
Conclusiones:
- Se ha demostrado un nuevo método para crear materiales ópticos quirales a partir de componentes achirales.
- La quiralidad inducida es estable incluso después de la eliminación del inductor quiral temporal.
- Este enfoque permite el diseño de películas basadas en s-PS con respuestas ópticas quirales a medida en longitudes de onda específicas.
- Los hallazgos abren nuevas vías para aplicaciones en dispositivos y sensores quirópticos.
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