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Síntesis controlada por el sentido hélice de poli (metil metacrilato) estereocomplejos ópticamente activos
Takehiro Kawauchi1, Atsushi Kitaura, Jiro Kumaki
1Yashima Super-structured Helix Project, Exploratory Research for Advanced Technology, Japan Science & Technology Agency, Japan. kawauchi@tutms.tut.ac.jp
Journal of the American Chemical Society
|August 15, 2008
Resumen
Se formaron estereocomplejos de poli (methacrilato de metilo) ópticamente activos mediante la inclusión de PMMA isotáctico dentro de una hélice de PMMA sindiotáctica encapsulada con fullereno. Esto dio como resultado una hélice de tres hilos con una memoria de helicidad macromolecular preservada.
Área de la Ciencia:
- Química de Polímeros La Química de Polímeros es la química de los polímeros.
- Química supramolecular de las moléculas.
- Espectroscopia Quiróptica Espectroscopia Quiróptica es la espectroscopia quiróptica que se utiliza para hacer espectroscopía.
Sus antecedentes:
- Los polímeros ópticamente activos exhiben propiedades quirópticas únicas.
- La memoria de helicidad macromolecular permite a los polímeros retener conformaciones helicoidales específicas.
- La encapsulación de fullereno puede moldear estructuras poliméricas.
Objetivo del estudio:
- Para preparar complejos estereoscópicos de poli (metil metacrilato) ópticamente activos.
- Para investigar la inclusión supramolecular controlada por el sentido de la hélice.
- Para explorar la formación de estructuras helicoidales de triple cadena.
Principales métodos:
- Síntesis de PMMA sindiotáctico ópticamente activo y encapsulado con fullereno.
- La inclusión supramolecular de PMMA isotáctico dentro del complejo fullereno-PMMA.
- Análisis mediante espectroscopia de dicroísmo circular vibratorio (VCD).
- Análisis computacional de los espectros de VCD.
Principales resultados:
- Preparación exitosa de los estereocomplejos PMMA ópticamente activos.
- El PMMA isotáctico reemplazó a los fullerenos encapsulados dentro de la hélice sindiotáctica del PMMA.
- Formación de una hélice de doble hebra por PMMA isotáctico con la misma mano que la hélice simple de PMMA sindiotáctico.
- Evidencia de una estructura topológica de hélice de triple cadena.
Conclusiones:
- Demostró un método novedoso para crear estereocomplejos con estructuras helicoidales controladas.
- Estableció un efecto de memoria de helicidad macromolecular en hélices PMMA de triple cadena.
- Destacó el papel de la plantilla de fullereno en la dirección del autoensamblaje del polímero.
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