Page 10 - Book of Invited & Keynotes Talks

th
8 Biannual Conference on Chemistry - CHEM 08

Unraveling the Elementary Steps of Photosensitizer Dynamics Using
Methods Across the Spectrum from IR to X-ray
O. Kühn, O. S. Bokareva, S. I. Bokarev
Universität Rostock, Institut für Physik, Albert-Einstein-Str. 23-24, 18059

Rostock, Germany

ABSTRACT
Transition metal complexes play an essential role as photosensitizers, photoemitters, and
dyes. The theoretical description of mechanistic details of the associated processes are
complicated due to (i) the nontrivial electronic structure with system sizes calling for density
functional theory, which is challenged by correlation effects and charge transfer transitions,
(ii) a pronounced spin-orbit coupling giving rise to spin forbidden mixing up to the point
where a classification in terms of spin-free states ceases to make sense, and (iii) the practical
use of photosensitizers as part of complex reaction schemes involving multiple reactants
and products. All together these points are shaping the landscape of multidimensional
nonadiabatic functional dynamics.During the last years, we have applied electronic structure
and theoretical spectroscopy methods to characterize the elementary steps of an exemplary
hydrogen-generating photocatalytic cycle employing on an Ir-photosensitizer and a Fe-
based water reduction catalyst. Our efforts comprised the electronic excitation and charge
separation, the reduction of the photosensitizer as well as the electron transfer to the Fe-
based catalyst. This talk will give an overview and address methodological challenges.
References
Bokarev, S. I.; Bokareva, O. S.; Kühn, O. Electronic Excitation Spectrum of the Photosensitizer
[Ir(ppy) 2(bpy)] . J Chem Phys 2012, 136, 214305
+
Neubauer, A.; Grell, G.; Friedrich, A.; Bokarev, S. I.; Schwarzbach, P.; Gärtner, F.; Surkus, A.-E.;
Junge, H.; Beller, M.; Kühn, O.; et al. Electron- and Energy-Transfer Processes in a Photocatalytic
System Based on an Ir(III)-Photosensitizer and an Iron Catalyst. J Phys Chem Lett 2014, 5, 1355–
1360
Bokarev, S. I.; Kühn, O.; Lochbrunner, S.; Junge, H.; Beller, M. Spin Density Distribution after
Electron Transfer from Triethylamine to an [Ir(ppy) 2(bpy)] Photosensitizer during Photocatalytic
+
Water Reduction. PhysChemChemPhys 2014, 16, 4789–4796.
Bokarev, S. I.; Bokareva, O. S.; Kühn, O. A Theoretical Perspective on Charge Transfer in
Photocatalysis. The Example of Ir-Based Systems. Coord. Chem. Rev. 2015, 304–305, 133–145.
Fischer, S.; Bokareva, O. S.; Barsch, E.; Bokarev, S. I.; Kühn, O.; Ludwig, R. Mechanistic Study of
Photocatalytic Hydrogen Generation with Simple Iron Carbonyls as Water Reduction Catalysts.
ChemCatChem 2016, 8, 404–411.
Bokareva, O. S.; Möhle, T.; Neubauer, A.; Bokarev, S. I.; Lochbrunner, S.; Kühn, O. Chemical
Tuning and Absorption Properties of Iridium Photosensitizers for Photocatalytic Applications.
Inorganics 2017, 5, 23

Talk Title
Unraveling the Elementary Steps of

Talk Date : Tuesday 3 March Photosensitizer Dynamics Using
2020 Methods Across the Spectrum from IR
Place: Hall A to X-ray
Time : 11:30-12:15

BOOK OF INVITED SPEAKERS & KEYNOTES CHEM 08 (2020) Page 10