🎓 [THESIS DEFENSE] – Louis Caussin will defend his PhD thesis:
🔬 “Photoswitchable radicals for the light control of single-molecule magnets”
📅 Monday 23 November 2026 at 14:30 – ISCR – University of Rennes – Amphi Grandjean This thesis is co-funded by EUR LUMOMAT and La Région Bretagne
This thesis is supervised by Prof. Lucie NOREL – ISCR – Université de Rennes and Prof. Kevin Bernot – INSA Rennes – ISCR – Université de Rennes
Examining Committee :
➖ Dr. Jennifer Molloy – CNRS/Université Grenoble Alpes
➖ Dr. Ie-Rang Jeon – CNRS/Université de Bordeaux
➖ Prof. David Canevet – Université d’Angers
➖ Prof. Mauro Perfetti – University of Florence
📄 [Abstract] Single-chain magnets exhibit magnetic bistability at the molecular scale and hold promise for high-density information storage. Controlling them with light would provide an additional level of control. This work combines dithienylethene photochromic units, nitronyl-nitroxide radicals, and lanthanide(III) ions, with photoisomerization intended to modulate both magnetic exchange interactions and the ligand field around the metal.
Four dithienylethene–nitronyl-nitroxide diradicals and three monoradical analogs were synthesized and characterized. The most compact diradical, previously unreported, exhibits an antiferromagnetic exchange interaction multiplied by a factor of 100 upon ring closure—the strongest reported to date for this family—as well as the first ON/OFF photomodulation of the luminescence of a nitronyl-nitroxide radical.
The coordination of these ligands to lanthanide(III) ions led to the first complexes integrating dithienylethene–nitronyl-nitroxide units, in both open and closed forms. Their photochromic and magnetic properties were studied, particularly using torque magnetometry.
These results lay the foundation for the development of photocommutable single-chaine magnets based on radicals.
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