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Un fenolato transitorio permite la relajación de Z-Tetra-ortho-fluoroazobenzeno al estado estable en segundos

William Brittain¹, Scott Barrett¹, Len Mouer¹

¹Department of Chemistry and Biochemistry, Texas State University, San Marcos, Texas, 78666, USA.

Angewandte Chemie (International ed. in English)

|August 22, 2025

Resumen

Desarrollamos una molécula híbrida que combinaba tetra-orto-fluoroazobenzenos (TFAs) con espiropirano. Este sistema acelera dramáticamente el TFA

Área de la Ciencia:

Fotónica molecular
Química orgánica
Ciencias de los materiales

Sus antecedentes:

Los tetra-orto-fluoroazobenzos (TFAs) poseen propiedades de fotoisomerización y estabilidad térmica únicas.
El control de la isomerización térmica de Z a E de los AGT es crucial para las aplicaciones sensibles a la luz, pero sigue siendo un desafío.

Objetivo del estudio:

Para crear un sistema molecular híbrido acoplando una subunidad TFA con un conmutador de espiropirano.
Investigar la aceleración de la isomerización TFA de Z a E dentro de este sistema híbrido.
Para explorar el control de estímulos externos sobre la isomerización de TFA a través del equilibrio espiropiran-merocianina.

Principales métodos:

Sintetizó una molécula híbrida que integraba las funcionalidades de TFA y espiropyran.
Estudió la cinética de la fotoisomerización utilizando técnicas espectroscópicas.
Efectos investigados del disolvente en las tasas de isomerización.
Mecanismos de aceleración analizados a través de la formación de especies transitorias.

Principales resultados:

El sistema híbrido exhibe una isomerización Z-E significativamente más rápida de la subunidad TFA en comparación con los compuestos modelo (1000x).
La aceleración de la isomerización está relacionada con el merocianina intermedio del espiropirano.
Se observaron aumentos de la tasa dependientes del disolvente de 100 a 1000 veces.
Se logró una notable aceleración de 10^6 veces de la isomerización de TFA a través del fotocromismo o el adsorbtiocromismo.

Conclusiones:

El acoplamiento de los TFAs con los espiropiranos crea un sistema híbrido con tasas de isomerización dramáticamente mejoradas.
El merocianina intermedio juega un papel clave en la aceleración de la isomerización TFA de Z a E.
Este enfoque híbrido ofrece una nueva estrategia para sistemas moleculares sensibles a la luz con propiedades sintonizables.

Palabras clave:

Fluoroazobenceno y sus derivados Merocianina y sus derivados Fenolato y sus derivados Solvatocrómico Espiropirano

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