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Chiralidad Planar Adaptativa de las arenas Pillar Invertible por Longitudes de Alkanos

Keisuke Adachi¹, Shixin Fa^1,2, Keisuke Wada¹

¹Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.

Journal of the American Chemical Society

|March 28, 2023

Resumen

Este estudio introduce un nuevo anfitrión pillar[5]areno capaz de adaptar su quiralidad en función de la longitud de los anfitriones n-alcanos incluidos. Este sistema molecular demuestra la inversión quiral dependiente de la longitud, ofreciendo nuevas posibilidades en la química huésped-invitado.

Área de la Ciencia:

Química supramolecular
Química entre anfitrión y huésped
Reconocimiento quiral

Sus antecedentes:

La quiralidad de la molécula huésped puede ser influenciada por las moléculas huésped.
La adaptación de la quiralidad del huésped a los n-alcanes neutrales y achirales es un desafío debido a las interacciones débiles.

Objetivo del estudio:

Desarrollar un sistema huésped que adapte su quiralidad en respuesta a las longitudes de n-alcano.
Investigar el mecanismo de la inversión quiral dependiente de la longitud en huéspedes macrocíclicos.

Principales métodos:

Utilizó un anfitrión macrocíclico basado en pilares[5]arenos con carbono estereogénico y átomos de bromo.
Utilizan n-alcanos de diferentes longitudes (n-pentano, n-hexano, n-heptano) como invitados.
Los hallazgos se respaldan con análisis de la estructura cristalina y cálculos teóricos.

Principales resultados:

El anfitrión pillar[5]areno exhibió una inversión quiral dependiente de la longitud, favoreciendo la forma pS con n-alcanos cortos y la forma pR con n-alcanos largos.
La temperatura influyó en la preferencia quiral, con el n-hexano favoreciendo la pR a temperaturas más altas y la pS a temperaturas más bajas.
Las estructuras cristalinas y los cálculos teóricos confirmaron las diferencias de estabilidad de los isómeros.

Conclusiones:

Demostró un sistema huésped único con quiralidad adaptable a longitudes de n-alcano.
Destacó el potencial de los huéspedes macrocíclicos en el reconocimiento molecular selectivo basado en las propiedades de los huéspedes.
Temperatura mostrada como un factor crítico en el control de la quiralidad adaptativa en complejos huésped-huésped.

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