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Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals
Published on: May 29, 2018
Dinámica nuclear coherente en el cambio estructural inducido por la luz ultrarrápida del complejo bis ((diimine)
Munetaka Iwamura1, Hidekazu Watanabe, Kunihiko Ishii
1Molecular Spectroscopy Laboratory, Advanced Science Institute (ASI), RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Journal of the American Chemical Society
|April 29, 2011
Resumen
Este estudio revela cambios estructurales ultrarrápidos en un complejo de cobre tras la fotoexcitación. Se observó el movimiento nuclear coherente en el estado excitado, lo que proporciona información sobre la dinámica molecular.
Área de la Ciencia:
- La fotoquímica es la fotoquímica.
- Espectroscopia ultrarrápida Espectroscopia ultrarrápida.
- Química computacional es la química computacional.
Sus antecedentes:
- Los complejos metálicos sufren cambios estructurales tras la fotoexcitación.
- Comprender la dinámica del estado excitado es crucial para la fotoquímica.
Objetivo del estudio:
- Para investigar el cambio estructural fotoinducido de [Cu(dmphen)2](+) utilizando espectroscopia ultra rápida.
- Para dilucidar la dinámica del estado excitado del singlete y el cruce entre sistemas.
Principales métodos:
- Espectroscopia ultrarrápida con una resolución de tiempo de 30 fs.
- Medidas de absorción con resolución de tiempo.
- Cálculos de la teoría funcional de la densidad dependiente del tiempo (TDDFT).
Principales resultados:
- Se observaron cambios espectrales distintos atribuidos a un cambio estructural D(2d) → D(2) en el estado excitado singlet.
- Confirmadas constantes de tiempo de ~0.8 ps para el cambio estructural y ~10 ps para el cruce intersistémico.
- Se detectó un movimiento nuclear coherente en el estado excitado, lo que indica una estructura vibratoria bien definida.
Conclusiones:
- La fotoexcitación induce modos de vibración específicos, incluidos los cambios en los enlaces Cu-ligando y la torsión del ligando.
- El estado singlet excitado mantiene su estructura y coherencia vibratoria durante un corto período.
- Los enfoques experimentales y computacionales combinados proporcionan una comprensión completa de la dinámica fotoinducida.
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