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Relajación vibratoria y cruce entre sistemas de complejos metálicos binucleares en solución
Renske M van der Veen1, Andrea Cannizzo, Frank van Mourik
1Ecole Polytechnique Fédérale de Lausanne, Laboratory of Ultrafast Spectroscopy, ISIC, 1015 Lausanne, Switzerland.
Journal of the American Chemical Society
|December 18, 2010
Resumen
Se estudiaron la relajación vibratoria ultrarrápida y las oscilaciones del paquete de ondas en el complejo [Pt2(P2O5H2)4]4-. Las interacciones de disolventes influyen significativamente en el enfriamiento vibratorio y las tasas de cruce intersistémico.
Área de la Ciencia:
- La fotoquímica es la fotoquímica.
- Química Física es la química física.
- La espectroscopia es una técnica de espectroscopia.
Sus antecedentes:
- Los complejos binucleares de platino exhiben interesantes propiedades fotofísicas.
- Comprender la dinámica ultrarrápida es crucial para el diseño de nuevos materiales.
Objetivo del estudio:
- Investigar la relajación vibratorio-electrónica ultrarrápida en [Pt2(P2O5H2)4]4-.
- Aclarar el papel del disolvente en la dinámica del estado excitado.
- Caracteriza la relajación vibratoria, las oscilaciones de los paquetes de ondas y el cruce entre sistemas.
Principales métodos:
- Espectroscopia de conversión hacia arriba de fluorescencia policromática de femtosegundo.
- Espectroscopia de absorción transitoria (TA) de banda ancha de femtosegundos en banda ancha. espectroscopia de absorción transitoria (TA) en banda ancha de femtosegundos. espectroscopia de absorción transitoria (TA) en banda ancha de femtosegundos.
- Estudios dependientes del disolvente. estudios dependientes del disolvente.
Principales resultados:
- Se observaron oscilaciones de paquetes de ondas de vibración de estiramiento Pt-Pt (224 fs período) en el estado (1) A 2 u).
- La relajación vibratoria y los tiempos de cruce intersistémico (ISC) muestran una fuerte dependencia del disolvente.
- Establecida disipación directa de energía del disolvente Pt para el enfriamiento vibratorio.
- Identificó el acoplamiento spin-vibrónico y la ruptura de simetría como factores impulsores para el ISC.
Conclusiones:
- [Pt2(P2O5H2)4]4- exhibe un comportamiento del oscilador armónico que se desvía de la descripción óptica de Bloch.
- La disipación directa de energía del disolvente Pt facilita el enfriamiento vibratorio.
- La estructura molecular, la energía y la simetría controlan las tasas de ISC a pesar del fuerte acoplamiento espín-órbita.
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