Talk given by

Prof. Stefan Haacke

Strasbourg University

CNRS-IPCMS

Strasbourg, France

Abstract:

The "Institut de Physique et Chimie des Matériaux de Strasbourg" (IPCMS, http://www.ipcms.unistra.fr/) is an interdisciplinary institute with a research profile combining fundamental physics and chemistry for new approaches in material science at the nanoscale. The talk will give a general overview of our research and outline more in detail a few emerging priority axes underscoring the interdisciplinary approach, and recent cutting-edge instrumental developments in the area of ultrafast spectroscopy and electron microscopy will be introduced.

In the second part, I will highlight two recent examples of topics under investigation in my research team. Using ultrafast UV-VIS spectroscopy we have made progress in understanding the molecular basis of the primary processes of vision and of primitive photo-synthesis at work in so-called retinal proteins [1]. It is well-known that these involve an ultrafast cis-trans photo-isomerization, but new information is now available as to how the protein environment steers this reaction in terms of speed and quantum efficiency [2]. A second example, is the development of new Fe(II) – N-heterocyclic carbene complexes with an enhanced ligand field splitting so as to avoid ultrafast spin crossover. As a result, these complexes display increased excited state lifetimes [3,4], which make them amenable to applications in solar cells and photo-catalysis.

References:

[1]"Ultrafast photo-induced reaction dynamics in bacteriorhodopsin and its Trp mutants", J. Briand, J. Léonard, and S. Haacke, J. Opt. 12 084004 (2010).

[2] "100 fs photo-isomerization with vibrational coherences but low quantum yield in Anabaena Sensory Rhodopsin", A. Cheminal, J. Léonard, S. Y. Kim, K.-H. Jung, H. Kandori, and S. Haacke, Phys. Chem. Chem. Phys., 17, 25429 – 25439 (2015).

[3] "An Iron-Based Photosensitizer with Extended Excited-State Lifetime: Photophysical and Photovoltaic Properties", T. Duchanois, T. Etienne, C. Cebrián, Li Liu, A. Monari, M. Beley, X. Assfeld, S. Haacke, P.C. Gros, Eur. J. Inorg. Chem. 14, 2469-2477 (2015).

[4] "A new record excited state ³MLCT lifetime for metalorganic Fe(II) complexes", L. Liu, T. Duchanois, T. Etienne, A. Monari, M. Beley, X. Assfeld, S. Haacke, P.C. Gros, Phys. Chem. Chem. Phys., 18, 12550-12556 (2016).