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Dinámica de reacción de un interruptor molecular revelada por la espectroscopia electrónica coherente bidimensional
Martin Kullmann1, Stefan Ruetzel, Johannes Buback
1Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
Journal of the American Chemical Society
|August 4, 2011
Resumen
La espectroscopia electrónica bidimensional revela la fotofísica de una molécula fotocrómica, el 6,8-dinitro-BIPS. Este estudio muestra la técnica.
Área de la Ciencia:
- Química Física es la química física.
- La espectroscopia es una técnica de espectroscopia.
- La fotoquímica es la fotoquímica.
Sus antecedentes:
- La espectroscopia electrónica coherente bidimensional (2D ES) se aplica típicamente a las moléculas con estructuras estáticas.
- Los sistemas fotocrómicos, como el 6,8-dinitro-BIPS, sufren cambios de color reversibles al exponerse a la luz.
- Comprender la dinámica de las reacciones fotocrómicas es crucial para las aplicaciones de la ciencia de los materiales.
Objetivo del estudio:
- Para investigar la fotofísica y la fotoquímica de 6,8-dinitro-BIPS disuelto utilizando 2D ES.
- Para analizar la dinámica del cierre de anillo fotoinducido en los dos isómeros de anillo abierto de 6,8-dinitro-BIPS.
- Demostrar la aplicabilidad de 2D ES para el estudio de procesos químicos reactivos.
Principales métodos:
- Se utilizó la espectroscopia electrónica de la transformada de Fourier bidimensional (2D FTES).
- Empleó pulsos de bomba de 20 fs a 605 nm y una sonda de supercontinuum en todo el espectro visible.
- Se ha estudiado el 6,8-dinitro-1',3',3'-trimetilspiro [2H-1-benzopirano-2,2'-indolina] (6,8-dinitro-BIPS) en solución.
Principales resultados:
- Se obtuvieron espectros electrónicos detallados en 2D para los dos isómeros de anillo abierto de 6,8-dinitro-BIPS.
- Proporcionó información sobre la fotofísica y la fotoquímica de los isómeros estudiados.
- Directamente indicado que la isomerización cis/trans no es un factor significativo en las fotorreacciones observadas.
Conclusiones:
- La espectroscopia electrónica 2D es una herramienta poderosa para analizar procesos reactivos en sistemas fotocrómicos.
- El estudio aclara las vías fotoquímicas de 6,8-dinitro-BIPS.
- Confirma la utilidad de 2D ES para sondear dinámicas moleculares complejas.
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