Alexandre CHEMIN PhD defense

Design, synthesis, and study of the properties of photoactive 1,2-dihydrophosphetenes and phospha-cyanines
Design, synthesis, and study of the properties of photoactive 1,2-dihydrophosphetenes and phospha-cyanines

Organometallics: Materials & Catalysis (OMC) team

Abstract
'This manuscript reports the synthesis and physicochemical characterization of novel π-conjugated organophosphorus systems. The first chapter focuses on the formation of compounds incorporating the 1,2-dihydrophosphetene motif (a four-membered heterocycle). By tuning the lateral substituents, we were able to demonstrate the formation of both fluorophores and photochromes. The latter exhibit high reversibility together with excellent thermal stability. These findings pave the way for the use of phosphorus-containing photochromes in various applications.
The second chapter is dedicated to the synthesis of polymethine cyanines in which the nitrogen atom is replaced by phosphorus. Through molecular engineering, we succeeded in synthesizing two new families of phospha-cyanines. Comprehensive studies of their properties in solution, in the solid state, as well as through theoretical modeling confirmed an ideal polymethine state. This state endows them with remarkable spectroscopic properties, including strong absorption and emission in the visible and near-infrared regions.'

Jury
Emmanuelle REMOND, Maitre de conférences, Université de Montpellier
Simon PASCAL, Chargé de recherche, Université de Nantes
Guy ROYAL, Professeur, Université de Grenoble
Julien BOIXEL, Chargé de recherches, Université de Rennes, ISCR
Pierre-Antoine BOUIT, Directeur de recherche, Université de Rennes, ISCR
Muriel HISSLER, Professeure, Université de Rennes, ISCR

Contacts
Pierre-Antoine Bouit, pierre-antoine.bouit@univ-rennes.fr