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Estabilización de los conjuntos de cucurbituril/invitado a través de las interacciones de largo alcance de Coulombic

Roymon Joseph¹, Anna Nkrumah, Ronald J Clark

¹Department of Chemistry and Biochemistry, Ohio University , Athens, Ohio 45701, United States.

Journal of the American Chemical Society

|April 18, 2014

Resumen

Cucurbit[n]urils (CB[n]) se unen fuertemente a los complejos metal-terpiridina a través de enlaces CH··O, impulsados por una entalpía favorable. CB[8] actúa como un vinculante, permitiendo la auto-clasificación y la formación de dinámicos, alternando metales oligómeros.

Área de la Ciencia:

Química supramolecular de las moléculas.
Coordinación Química de la Coordinación
Química entre anfitrión y huésped.

Sus antecedentes:

Cucurbit[n]urils (CB[n]) son anfitriones macrocíclicos conocidos por su fuerte unión al huésped.
Los complejos metal-terpiridina son versátiles bloques de construcción en la química supramolecular.
Comprender las interacciones no covalentes es crucial para diseñar conjuntos moleculares complejos.

Objetivo del estudio:

Para investigar las interacciones no covalentes entre cucurbit[n]urils (CB[n]) y los ligandos de terpiridina unidos a metales.
Para explorar el papel de CB[n] como un enlace en la formación de conjuntos supramoleculares dinámicos.
Demostrar fenómenos de autoclasificación en la construcción de oligómeros metalo-supramoleculares.

Principales métodos:

Síntesis y caracterización de los complejos de terpiridina de hierro (II) e iridio (III) con diferentes 4'-sustitutos.
Estudios vinculantes utilizando cucurbit[n]urils (CB[6]-CB[8]) para cuantificar las interacciones huésped-anfitrión.
Análisis espectroscópicos y estructurales para elucidar los modos de unión y la formación de ensamblajes.

Principales resultados:

Se observaron fuertes interacciones de enlace de hidrógeno CH··O entre los complejos CB[n] y metal-terpiridina.
El enlace es impulsado por una combinación de entalpía altamente favorable y entropía desfavorable.
CB[8] vinculó eficazmente los complejos metal-terpiridina, formando oligómeros dinámicos a través de la autoclasificación de los sustituyentes.

Conclusiones:

Cucurbit[n]urils puede mediar interacciones sin precedentes con complejos de metal-terpiridina a través de ligandos orgánicos.
CB[8] actúa como un vinculante versátil "blando", permitiendo la construcción de oligómeros metalo-supramoleculares bien definidos y alternados.
El comportamiento de autoclasificación observado ofrece una vía para el ensamblaje controlado de complejas arquitecturas supramoleculares.

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