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El autoensamblaje y el dicroísmo circular inducido en supramoleculas dendríticas con grupos colgantes colestéricos
Antti J Soininen1, Edis Kasëmi, A Dieter Schlüter
1Department of Applied Physics, Aalto University School of Science and Technology, 02150 Espoo, Finland.
Journal of the American Chemical Society
|August 5, 2010
Resumen
Las macromoléculas dendríticas quirales se autoensamblan en estructuras ordenadas de estado sólido, mejorando las propiedades ópticas como el dicroísmo circular (CD). Esta quiralidad supramolecular surge de la complejación iónica, lo que demuestra que los dendrímeros son plantillas versátiles para materiales ópticos avanzados.
Área de la Ciencia:
- Química supramolecular de las moléculas.
- Ciencia de los materiales Ciencia de los materiales.
- Química de Polímeros La Química de Polímeros es la química de los polímeros.
Sus antecedentes:
- Las moléculas quirales poseen propiedades ópticas únicas.
- Las macromoléculas dendríticas ofrecen arquitecturas sintonizables.
- El autoensamblaje es una estrategia clave para crear materiales ordenados.
Objetivo del estudio:
- Para investigar las estructuras de estado sólido de las supramoleculas quirales formadas por macromoleculas dendríticas.
- Explorar la relación entre el orden estructural y las propiedades ópticas (absorción de rayos UV y CD).
- Para demostrar el uso de macromoléculas dendríticas como plantillas para inducir la quiralidad supramolecular.
Principales métodos:
- Complejación iónica de grupos colestéricos quirales con macromoléculas dendríticas achirales.
- Construcción de una serie homóloga de complejos con generaciones dendríticas variables (1-3).
- Caracterización estructural utilizando dispersión de rayos X de ángulo pequeño (SAXS) y microscopía electrónica de transmisión (TEM).
Principales resultados:
- Las estructuras autoensambladas exhibieron varias fases: lamelar, columnar hexagonal, columnar oblicuo y columnar rectangular.
- La actividad óptica mostró cambios sistemáticos en la absorción de los rayos UV y la mejora de las señales de dicroísmo circular (CD).
- Las señales ópticas mejoradas, particularmente CD, se correlacionan con el orden y las longitudes de correlación de celosía de las estructuras de estado sólido.
Conclusiones:
- Las macromoléculas dendríticas actúan como plantillas supramoleculares efectivas para organizar las unidades quirales.
- El grado de libertad en las macromoléculas dendríticas influye en el orden en las estructuras de estado sólido autoensambladas.
- Estos sistemas exhiben propiedades ópticas sintonizables y amplificadas, mostrando el potencial de los materiales avanzados.
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