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Estructuras y energéticas de los isómeros del complejo protonado de bipiridina-cucurbituril en la fase gaseosa

Doui Kim¹, Jongcheol Seo^1,2

¹Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongsangbuk-do 37673, Republic of Korea. jongcheol.seo@postech.ac.kr.

Physical chemistry chemical physics : PCCP

|August 29, 2025

Resumen

Los cucurbituriles (CB[6] y CB[7]) forman complejos huésped-huésped distintos con las bipirinas. La carga y el tamaño de la cavidad anfitriona influyen críticamente en si las bipirinas se incluyen o excluyen, lo que afecta el diseño del ensamblaje supramolecular.

Área de la Ciencia:

Química supramolecular
Química Física
Física y Química

Sus antecedentes:

Los cucurbituriles son huéspedes macrocíclicos conocidos por su capacidad para formar complejos de inclusión.
Las bipiridinas son ligandos versátiles con propiedades electrónicas sintonizables y diversas aplicaciones.
Comprender las interacciones huésped-huésped es crucial para el diseño de materiales funcionales avanzados.

Objetivo del estudio:

Investigar el isomerismo de la fase gaseosa y la estabilidad de los complejos cucurbituril-bipiridina.
Determinar la influencia de la geometría molecular y la distribución de la carga en la formación compleja.
Explorar el papel del tamaño de la cavidad anfitriona y la flexibilidad en la inclusión de los huéspedes.

Principales métodos:

Espectrometría de movilidad iónica-espectrometría de masas (IMS-MS) para la separación y caracterización de isómeros.
Experimentos de disociación inducida por colisión para evaluar la estabilidad compleja.
Cálculos de la teoría funcional de la densidad (DFT) para modelar estructuras e interacciones.

Principales resultados:

Se observaron isómeros complejos de inclusión y exclusión distintos para los sistemas de cucurbituril-bipiridina.
CB[6] formó preferentemente complejos de exclusión con bipiridinas de un solo protón.
Las bipiridinas doblemente protonadas formaron complejos de inclusión estables con CB a través de interacciones de carga-portal.
CB[7] formaba complejos de inclusión consistentes con todos los isómeros de la bipiridina, independientemente del estado de carga.

Conclusiones:

El isomerismo y la estabilidad de la fase gaseosa se rigen por la localización de la carga, la flexibilidad del huésped y los efectos específicos de la fase.
Los hallazgos proporcionan información sobre el diseño de materiales supramoleculares basados en bipiridina o bipiridinium.
El estudio destaca la importancia de las interacciones electrostáticas y la dinámica de la cavidad del huésped en la química huésped-huésped.

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