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Autoensamblaje de prismas trigonales dirigido por la coordinación y dirigido por la cara. La quiralidad
Douglas C Caskey1, Takuya Yamamoto, Chris Addicott
1Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, USA.
Journal of the American Chemical Society
|May 22, 2008
Resumen
Los investigadores crearon prismas trigonales quirales utilizando enlaces de platino y conectores de estrellas. Se observó la transferencia de quiralidad, con distintos comportamientos de borde de anillo de piridina y dinámicas de interconversión dependientes de la temperatura.
Área de la Ciencia:
- Química supramolecular de las moléculas.
- Coordinación Química de la Coordinación
- Ciencia de los materiales Ciencia de los materiales.
Sus antecedentes:
- El autoensamblaje impulsado por la coordinación es un método poderoso para construir arquitecturas moleculares complejas.
- Los prismas trigonales representan una estructura poliédrica fundamental con aplicaciones potenciales en el reconocimiento molecular y la catálisis.
Objetivo del estudio:
- Para sintetizar y caracterizar nuevos prismas trigonales utilizando un enfoque de autoensamblaje dirigido a la cara.
- Para investigar la influencia de los conectores de estrellas conformacionalmente quirales en la quiralidad del prisma resultante.
- Para estudiar el comportamiento dinámico de los bordes de los anillos de piridina dentro de los prismas ensamblados.
Principales métodos:
- Síntesis de cuatro prismas trigonales diferentes a través del autoensamblaje impulsado por la coordinación.
- Caracterización mediante RMN multinuclear y DOSY, y espectrometría de masas dual ESI-FT-ICR.
- Análisis computacional utilizando la mecánica molecular.
- Estudios cinéticos a través del análisis de la forma de la línea y 1-D EXCHSY RMN para la interconversión de bordes.
Principales resultados:
- Se lograron altos rendimientos de cuatro prismas trigonales distintos sin ayuda de plantillas.
- La quiralidad se comunicó con éxito desde el conector estelar al prisma, demostrando la transferencia de quiralidad.
- Los datos de RMN confirmaron bordes de anillos de piridina distintos y revelaron dinámicas de interconversión dependientes de la temperatura.
- Se observaron dos energías de activación distintas para la rotación del anillo de piridina, lo que sugiere un comportamiento dinámico complejo.
Conclusiones:
- El autoensamblaje dirigido hacia la cara es una ruta eficiente hacia complejas estructuras quirales supramoleculares.
- Los bloques de construcción conformacionalmente quirales pueden inducir la quiralidad en ensamblajes poliédricos.
- El comportamiento dinámico de los bordes del prisma es complejo y exhibe transiciones dependientes de la temperatura.
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