Thesis Defense – Axel Riquet – Tuesday December 9th 2025: Möbius hexaphyrins: towards metallo-allosteric receptors with photoswitchable chirality

🎓 Thesis defense – Axel Riquet will defend her PhD thesis: möbius hexaphyrins: towards metallo-allosteric receptors with photoswitchable chirality
📅 Tuesday December 9th 2025 at 13:30 at the Rennes Institute of Chemical Sciences – Beaulieu Campus – Salle 160

This thesis is supervised by Dr. Stéphane Le Gac – ISRC / Université de Rennes
Examining Committee :
➖ Dr. Céline Olivier – Institut des Sciences Moléculaires de Bordeaux – Reviewer
➖ Prof. Alexandre Martinez – Institut des Sciences Moléculaires de Marseille – Reviewer
➖ Dr. Laure Guy – École Normale Supérieure de Lyon – Examiner

This thesis is supported by University of Rennes

📄 [Abstract] Hexaphyrins are dynamic pyrrolic macrocycles which are able to adopt a Möbius ring conformation. This peculiar scaffold possesses an inherent topological helical chirality. This thesis focuses on the chirality induction and its modulation. To achieve this, several innovative strategies have been employed. Firstly, with the use of hexaphyrine bearing a chiral amine or carboxylic acid arm. The formation of zinc(II) complexes with exogeneous azo ligands allowed the obtention of impressive chirality inductions with d.e. up to >95%. The chiroptical activity of these systems has been modulated thanks to the trans->cis photoisomerization of the azo ligand giving rise to the formation of the very first Möbius ring with photoswitchable chiroptical activity. Also, new hexaphyrins with a second chiral recognition site composed of a squaramid unit, overhanging the ring, have been developped. Chirality inductions by remote control have been obtained thanks to different processes such as recognition or protonation. The modulation of the arrangement of the two recognition sites by conformational changes induced by complexation has also been observed. The promising results of these two strategies lay the foundation for the formation of allosteric receptors with photoswitchable chirality.

🎓 Soutenance de Thèse – Axel Riquel soutiendra sa thèse intitulée : hexaphyrines de Möbius : vers des récepteurs métallo-allostériques à chiralité photo-commutable
📅 Mardi 9 Décembre 2025 à 13h30 à l’Institut des Sciences Chimiques de Rennes – Campus de Beaulieu – Salle 160

Cette thèse est dirigée par Dr. Stéphane Le Gac – ISRC / Université de Rennes
Jury :
➖ Dr. Céline Olivier – Institut des Sciences Moléculaires de Bordeaux – Rapporteur
➖ Prof. Alexandre Martinez – Institut des Sciences Moléculaires de Marseille – Rapporteur
➖ Dr. Laure Guy – École Normale Supérieure de Lyon – Examinatrice

Cette thèse est soutenue par l’Université de Rennes