Yoann FREROUX PhD defense
Luminescent lanthanide(III) complexes with dynamic optical responses
Freitag 7 November 2025, 09:30Passed
Organometallics: Materials and Catalysis (OMC) team
Abstract:
Luminescent lanthanide(III) complexes with dynamic optical responses
The photo-induced modulation of the luminescence of lanthanide(III) complexes using photochromic units, in particular diarylethenes, represents an emerging field with promising applications, particularly in anticounterfeiting. However, this field remains limited by several major challenges: (i) extending the emission properties from the visible to the near-infrared (NIR), (ii) implementing non-destructive emission readout, and (iii) integrating these systems into solid matrices while preserving their photophysical performances.
In this context, this thesis work focused first on the synthesis of new difluoroborate-core fluorophores used as efficient antennae for ytterbium(III) and erbium(III) complexes emitting in the NIR. These ligands have high molar extinction coefficients and dual visible/infrared emission, that made it possible to develop photochromic complexes with high luminescence contrast and, for the first time, non-destructive readout of erbium(III) emission.
The second area of research focused on the synthesis and study of new diarylethene derivatives for modulating the luminescence of lanthanides(III) emitting in the visible range, such as terbium(III), europium(III) and samarium(III). This work resulted in the first example of photomodulation of samarium(III) luminescence by a photochrome derivative.
Finally, the integration of complexes into solid matrixes was explored with a view to practical applications. A comparative study of different matrixes showed the decisive influence of the nature of the polymer and the doped complexes on the photophysical properties of the material.
Jury:
- Célia Bonnet, Directrice de Recherche CNRS, Centre de Biophysique Moléculaire d’Orléans / Reporter
- Simon Pascal, Chargé de Recherche CNRS, CEISAM, Université de Nantes / Reporter
- Keitaro Nakatani, Professeur des Universités, Ecole Normale Supérieure Paris-Saclay / Examiner
- Olivier Maury, Directeur de Recherche CNRS, Ecole Normale Supérieure de Lyon / Examiner
- Lucie Norel, Professeure des Universités, Université de Rennes / PhD Supervisor
- Stéphane Rigaut, Professeur des Universités, Université de Rennes / PhD Co-Supervisor
Contacts:
Yoann Fréroux, yoann.freroux@univ-rennes.fr
Stéphane Rigaut, stephane.rigaut@univ-rennes.fr
Lucie Norel, lucie.norel@univ-rennes.fr
