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Interacciones débiles que dominan el autoensamblaje supramolecular en una sal: una polimerización topoquímica
Zhong Li1, Frank W Fowler, Joseph W Lauher
1Department of Chemistry, State University of New York, Stony Brook, New York, 11794-3400, USA.
Journal of the American Chemical Society
|January 15, 2009
Resumen
Los investigadores lograron la primera polimerización de un solo cristal a un solo cristal de diacetilenos sustituidos por arilo utilizando un sistema anfitrión-invitado. Este método produce cristales de polímero conjugado libres de defectos, superando los desafíos con la rigidez monomérica.
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.
- La cristalografía es una técnica de cristalografía.
Sus antecedentes:
- La polimerización topoquímica de un solo cristal a un solo cristal (SCSC) ofrece una ruta hacia cristales de polímero conjugados altamente ordenados y libres de defectos.
- Los diacetilenos sustituidos por arilo son deseables para una mejor conjugación, pero han resistido la polimerización SCSC debido a la rigidez monomérica y los desafíos de control supramolecular.
Objetivo del estudio:
- Desarrollar un método para la polimerización SCSC de diacetilenos sustituidos por arilo.
- Para superar la rigidez y los problemas de ordenamiento supramolecular asociados con estos monómeros.
Principales métodos:
- Diseño y síntesis de un sistema anfitrión-invitado utilizando un anfitrión de ácido dicarboxílico de oxalamida y un invitado de fenildiacetileno terminal (DABzNH(2)).
- Utilizó las interacciones de enlace de hidrógeno para controlar el ensamblaje supramolecular y lograr una distancia de repetición de 4,9 Å.
- Se empleó recocido lento durante tres meses para inducir la polimerización de SCSC.
Principales resultados:
- Se sintetizó y cristalizó con éxito la sal huésped-huésped (DABzNH(3)) ((2)og, confirmando la organización supramolecular diseñada.
- Logró la primera polimerización SCSC reportada de un diacetileno sustituido por arilo, obteniendo un monocristal poli (aryldiacetileno).
- La estructura del polímero resultante reveló una vía de reacción inesperada que implicaba un movimiento significativo del sustituto aromático rígido.
Conclusiones:
- La química huésped-invitado proporciona una estrategia viable para controlar el embalaje en estado sólido de monómeros rígidos para la polimerización SCSC.
- Este trabajo demuestra la viabilidad de producir poli (aryldiacetileno) altamente cristalino a través de la polimerización SCSC.
- El estudio abre nuevas vías para sintetizar polímeros conjugados avanzados con propiedades a medida.
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