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El movimiento molecular y la interconversión conformacional de Ir ((I) · COD incluidos en el cavitando de octaamida

Saša Korom¹, Eddy Martin¹, Stefano A Serapian¹

¹Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology , Avgda. Països Catalans 16, 43007 Tarragona, Spain.

Journal of the American Chemical Society

|January 27, 2016

Resumen

La rotación restringida de los complejos de iridio dentro de una cavidad y huésped crea nuevas formas quirales. Esta complejación supramolecular mejora la quiralidad e influye en el movimiento molecular, ofreciendo información sobre la química huésped-huésped.

Área de la Ciencia:

Química supramolecular
Química organometálica
Química Física y Orgánica

Sus antecedentes:

La cavidad de octaamida de Rebek proporciona un entorno quiral para las moléculas huéspedes.
Comprender las interacciones huésped-huésped es crucial para diseñar nuevos sistemas moleculares.

Objetivo del estudio:

Para investigar la rotación axial de los complejos heterolepticos L2·Ir(I) ·1,5-cicloctadieno (COD) dentro de un cavitando.
Explorar el impacto del confinamiento en la quiralidad y la dinámica de los huéspedes organometálicos.

Principales métodos:

Espectroscopia de resonancia magnética nuclear de protones (1H NMR) a temperaturas variables.
Análisis computacional para apoyar las observaciones experimentales.
El análisis de Van't Hoff para determinar los parámetros termodinámicos.

Principales resultados:

Rotación axial restringida de los complejos de Ir ((I) -COD dentro de la cavidad observada a través de RMN de 1H.
Cambios en la simetría (C2 a C4) del complejo dependientes de la temperatura.
Aparición de nuevas formas quirales a bajas temperaturas debido a la interconversión conformacional restringida.

Conclusiones:

El confinamiento dentro de la cavidad quiral induce una mayor barrera de racemicidad para el complejo Ir ((I) -COD.
La inclusión es un proceso endotérmico impulsado por la entropía.
Los complejos anfitrión-invitado quirales exhiben propiedades y dinámicas estéreoquímicas únicas.

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