Post-Doc position in ultrafast photo-emission spectroscopy of rhodopsin-mimicking photo-switches, IPCMS/MBI, France/Germany

University of Strasbourg – CNRS, IPCMS, Prof. Stefan Haacke
Max-Born-Institute, Berlin, Dr. Oleg Kornilov


Rhodopsins are the protein photo-receptors for vision in vertebrates. Microbial organisms use them,
too, but for other forms of photo-sensing or for primitive photosynthesis. From a molecular point of
view, the start for these processes is photo-isomerisation: light converts the chromophore retinal from
its cis to the trans form, a photo-chemical process, which occurs within a few hundreds of
femtoseconds and with > 50% quantum efficiency.
Photo-isomerisation implies large molecular motion, out-of-plane bond twists and rotation around C-
C bonds of retinal. Quantum mechanically, the transition from cis to trans occurs when these motions
make the electronic excited and ground states degenerate, at the so-called conical intersections (CInt).
Quantum chemistry has predicted these transition states to be the decisive states determining the
quantum efficiency of the reaction, but CInt’s have so far escaped from direct observation in standard
UV/VIS/mid-IR pump-probe transient absorption experiments.
In this joint collaboration between the Max-Born-Institute, Berlin (Dr. O. Kornilov) and the IPCMS
Strasbourg (Dr. J. Léonard & Prof. S. Haacke), we bring together our expertise to investigate the CInt
of rhodopsin-mimicking photo-switches using novel tools of of femtosecond and attosecond XUV
physics. In particular, we plan to apply the method of XUV time-resolved photoelectron spectroscopy
(XUPS) to investigate Cints in rhodopsin-mimicking systems.


JOB DESCRIPTION
Within a joint collaboration of the above partner labs, the post-doc position is located in both ultrafast
spectroscopy labs in Strasbourg (IPCMS) and at MBI, Berlin. The Strasbourg team has a long-standing
experience with these particular, vibrationally coherent photo-switches 1 , studied by broadband
UV/VIS TAS with sub-10fs resolution 2 . The team of Dr. O. Kornilov at MBI runs a state-of-the-art
femtosecond UV-pump-HHG/XUPS-probe experiment with liquid jets 3 . In recent experiments, the
ground state XUPS spectra of the photo-switches were obtained, for both anionic and cationic forms
with high photo-emission yield. The first pump-probe experiments are in progress at MBI.
The post-doc will complete the first proof-of-principle phase on well-characterised molecules, in Berlin,
before the project is extended to new complexes aimed at studying the influence of vibrational
coherence and chemical substitutions on the isomerisation quantum yield and dynamics at the CInt.
This second phase implies experiments both in Strasbourg and Berlin, relying on the above set-ups.
Theoretical support will be provided by Prof. M. Olivucci (U Siena & Bowling Green), inventor of the
photo-switches, and Dr. S. Gozem (GSU Atlanta). Photo-switches will be designed for this project and
provided in sufficient amount by chemistry partners. The candidate should posess good knowledge in
molecular physics and/or physical chemistry and have to be ready to utilize novel non-standard
experimental methods and perform advanced data analysis.
The post-doc, since in an early stage of his career, is encouraged to pursue new ideas, publish first-
class papers and present his work at conferences, mentor graduate students, and contribute to fund
raising.

MINIMUM QUALIFICATIONS
Doctoral Degree in Physics, Chemistry, or Photonics and demonstrated research ability. Preferred
applicants should have a strong background in ultrafast optics, and molecular spectroscopy, possibly
in the condensed phase. We like to work with team players and young enthusiastic scientists attracted
by a broad interdisciplinary horizon, and an international collaboration.
The ideal candidate has two years of research experience in the field of ultrafast optics and
spectroscopy. Experience with synthesis of organic molecules, data analysis, and new technical
developments, including software, are a plus. Starting date: ASAP.
Applicants should send a CV and cover letter summarizing previous expertise and research interests,
and arrange for a letter of recommendation. Informal inquiries can be sent to haacke@unistra.fr or
oleg.kornilov@mbi-berlin.de.
Funding for this project comes from the Strasbourg Foundation for Research in Chemistry
(https://icfrc.fr/), with a monthly net salary in the 2’200-2’500 € range, depending on experience.

1 M. Gueye, M. Paolino, E. Gindensperger, S. Haacke, M. Olivucci, J. Léonard, Faraday Discussions, DOI:
10.1039/C9FD00062C;
2 M. Gueye, M. Manathunga, Y. Orozco, M. Paolino, S. Fusi, S. Haacke, M. Olivucci, and J. Léonard, Nature Comm. 9, 313
(2018); DOI: 10.1038/s41467-017-02668-w
3 J. Hummert, G. Reitsma, N. Mayer, E. Ikonnikov, M. Eckstein, O. Kornilov, J. Phys. Chem. Lett. 2018, 9, 6649−6655