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Las figuras homoquirales y mesoquirales representan ocho nudos y un enlace de Salomón
Nandhini Ponnuswamy1, Fabien B L Cougnon, G Dan Pantoş
1University Chemical Laboratory, University of Cambridge , Lensfield Road, CB2 1EW, Cambridge, U.K.
Journal of the American Chemical Society
|May 17, 2014
Resumen
Los investigadores crearon una biblioteca de macrociclos en el agua utilizando un bloque de construcción quiral. El estudio identificó un vínculo de Salomón y un nudo de la figura ocho, revelando un vínculo entre la quiralidad de los bloques de construcción y la topología resultante.
Área de la Ciencia:
- Química supramolecular de las moléculas.
- Química orgánica es la química orgánica.
- Ciencia de los materiales Ciencia de los materiales.
Sus antecedentes:
- Los bloques de construcción basados en naftalenediimida (NDI) son versátiles para la construcción de arquitecturas moleculares complejas.
- La formación de macrociclos topológicamente interesantes en solución, particularmente en agua, sigue siendo un desafío significativo.
- Comprender la relación entre la quiralidad de los bloques de construcción y la topología de las estructuras autoensambladas es crucial para el diseño racional.
Objetivo del estudio:
- Para sintetizar y caracterizar una biblioteca de macrociclos de disulfuro utilizando un bloque de construcción homoquiral basado en NDI en agua.
- Identificar los isómeros topológicos formados y dilucidar los mecanismos que rigen su formación.
- Para investigar la influencia de la quiralidad de punto del bloque de construcción en la topología del macrociclo resultante.
Principales métodos:
- Autoensamblaje de un bloque de construcción homoquiral basado en naftalenodiimida en solución acuosa.
- Formación de macrociclos de disulfuro a través del acoplamiento oxidativo.
- Separación e identificación de isómeros topológicos utilizando cromatografía líquida de alto rendimiento (HPLC).
- Asignación estructural de los isómeros principales basada en su comportamiento cromatográfico y características topológicas conocidas.
Principales resultados:
- Se formó una biblioteca de macrociclos disulfuro, que contiene varios isómeros topológicos.
- Las especies más abundantes fueron un enlace de Salomón topológicamente quiral (60% por HPLC) y una figura topológicamente achiral de ocho nudos (18% por HPLC).
- El uso de una mezcla racémica de bloques de construcción dio como resultado la formación casi cuantitativa de una figura meso más estable de ocho nudos.
- Se observó una correlación entre la quiralidad puntual del bloque de construcción y la quiralidad topológica del producto macrocíclico principal.
Conclusiones:
- La quiralidad del bloque de construcción basado en NDI influye significativamente en la topología de los macrociclos resultantes.
- La formación de isómeros topológicos específicos, como el enlace de Salomón y el nudo de la figura ocho, está controlada por la estereoquímica del material de partida.
- Este trabajo sugiere una nueva estrategia para la construcción de topologías moleculares complejas mediante el control de la quiralidad y la rigidez de los bloques de construcción.
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