Ultrafast photo-induced charge transfer unveiled by two-dimensional electronic spectroscopy

Autor(en)

Oliver Bixner, Vladimir Lukes, Tomas Mancal, Jürgen Hauer, Franz Milota, Michael Fischer, Igor Pugliesi, Maximilian Bradler, Walther Schmid, Eberhard Riedle, Harald Kauffmann, Niklas Christensson

Abstrakt

The interaction of exciton and charge transfer (CT) states plays a central role in photo-induced CT processes in chemistry, biology, and physics. In this work, we use a combination of two-dimensional electronic spectroscopy (2D-ES), pump-probe measurements, and quantum chemistry to investigate the ultrafast CT dynamics in a lutetium bisphthalocyanine dimer in different oxidation states. It is found that in the anionic form, the combination of strong CT-exciton interaction and electronic asymmetry induced by a counter-ion enables CT between the two macrocycles of the complex on a 30 fs timescale. Following optical excitation, a chain of electron and hole transfer steps gives rise to characteristic cross-peak dynamics in the electronic 2D spectra, and we monitor how the excited state charge density ultimately localizes on the macrocycle closest to the counter-ion within 100 fs. A comparison with the dynamics in the radical species further elucidates how CT states modulate the electronic structure and tune fs-reaction dynamics. Our experiments demonstrate the unique capability of 2D-ES in combination with other methods to decipher ultrafast CT dynamics

Organisation(en)

Institut für Organische Chemie, Institut für Physikalische Chemie, Elektronische Materialeigenschaften

Externe Organisation(en)

Slovak University of Technology in Bratislava, Charles University Prague, Ludwig-Maximilians-Universität München

Journal

Journal of Chemical Physics

Band

136

Anzahl der Seiten

12

ISSN

0021-9606

DOI

https://doi.org/10.1063/1.4720492

Publikationsdatum

2012

Peer-reviewed

Ja

ÖFOS 2012

104017 Physikalische Chemie, 1030 Physik, Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/f1cb2e3e-cfab-46a3-8f8a-b3cb496795ed