Regensburg 2010 – wissenschaftliches Programm
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DF: Fachverband Dielektrische Festkörper
DF 9: Focus Session: Structural dynamics in photoexcited molecules
DF 9.5: Hauptvortrag
Mittwoch, 24. März 2010, 11:40–12:15, H11
Ultrafast photochromism of fulgides — •Markus Braun1,2, Simone Draxler2, Thomas Brust2, and Stephan Malkmus2 — 1Institut für Physikalische und Theoretische Chemie, Johann Wolfgang Goethe-Universität Frankfurt, Max von Laue-Strasse 7, 60438 Frankfurt am Main, Germany — 2Lehrstuhl für BioMolekulare Optik, Oettingenstr. 67, Ludwig-Maximilians-Universität München, 80538 München, Germany
Pump-probe spectroscopy with fs-time resolution is a powerful tool to elucidate reaction pathways of complex photoreactions. We use pulse sequences to trigger and influence the reaction dynamics of photochromic indolylfulgides [1]. These experiments give deeper insight in the mechanism of the light-induced pericyclic ring-opening/ring-closure reactions for those molecular switches. The pericyclic reactions occur ultrafast without long-lived intermediates and are associated with a definite change of the steady state absorption spectrum. The ground state isomers are thermally stable, which is favourable for distinct applications (memory) [2]. The ultrafast photoreactions are studied by fs-pump-probe spectroscopy in the UV/Vis and the influence of vibrational excess energy (temperature, wavelength, pre-excitation) on the dynamics and yield is investigated [3].
[1] S. Draxler et al., Phys. Chem. Chem. Phys. 11 (2009) 5019-5027
[2] S. Malkmus et al., Adv. Funct. Mater. 17 (2007) 3657-3662
[3] T. Brust et al., J. Photochem. Photobiol. A 207 (2009) 209-216