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Bases mecánicas para el cambio de luz roja de iones de azonio

Miroslav Medved'^1,2, Mariangela Di Donato^3,4, Wybren Jan Buma^5,6

¹Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacký University, Šlechtitelů 241/27, Olomouc, 783 71 Czech Republic.

Journal of the American Chemical Society

|September 1, 2023

Resumen

Los iones de azonio protonados se someten a una fotoisomerización rápida con luz roja, lo que permite el fotocontrol en los sistemas biológicos. Comprender su relajación térmica dependiente del pH es clave para diseñar herramientas moleculares mejoradas para la fotofarmacología.

Área de la Ciencia:

La fotoquímica
Química supramolecular
Biofísica y Química

Sus antecedentes:

Los iones de azonio son moléculas fotointercambiables prometedoras para aplicaciones como la fotofarmacología.
Una comprensión mecanicista detallada de su fotoisomerización y relajación térmica es crucial para el diseño y la aplicación racionales.

Objetivo del estudio:

Elucidar el mecanismo de fotoisomerización y relajación térmica de los iones de azonio protonados.
Para proporcionar una comprensión completa de su comportamiento de conmutación de fotos dependiente del pH.

Principales métodos:

Espectroscopia de absorción transitoria con resolución de tiempo (en escalas de tiempo de subpicosegundos a nanosegundos).
Los cálculos químicos cuánticos.

Principales resultados:

La absorción de fotones por iones de azonio E-H+ protonados induce una isomerización rápida (en picosegundos) a la forma Z-H+ protonada.
La transferencia de protones al disolvente en una escala de tiempo de microsegundos establece un equilibrio dependiente del pH entre las especies Z y Z-H+.
Las tasas de relajación térmica son altamente dependientes del pH, siendo la isomerización de Z-H+ a E-H+ significativamente más rápida que la isomerización de Z a E.

Conclusiones:

El estudio proporciona la primera imagen mecanicista completa de la foto conmutación de iones de azonio en un rango de valores de pH.
Los hallazgos destacan las características clave para optimizar los iones de azonio para mejorar el fotocontrol de las biomoléculas.

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