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

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

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(s)
Department of Organic Chemistry, Department of Physical Chemistry, Electronic Properties of Materials
External organisation(s)
Slovak University of Technology in Bratislava, Charles University Prague, Ludwig-Maximilians-Universität München
Journal
Journal of Chemical Physics
Volume
136
No. of pages
12
ISSN
0021-9606
DOI
https://doi.org/10.1063/1.4720492
Publication date
2012
Peer reviewed
Yes
Austrian Fields of Science 2012
104017 Physical chemistry, 1030 Physics, Astronomy
Portal url
https://ucrisportal.univie.ac.at/en/publications/ultrafast-photoinduced-charge-transfer-unveiled-by-twodimensional-electronic-spectroscopy(f1cb2e3e-cfab-46a3-8f8a-b3cb496795ed).html