Reversible soft-mechanochemical control of biaryl conformations through crosslinking in a 3D macromolecular network.
Fiche publication
Date publication
août 2020
Journal
Angewandte Chemie (International ed. in English)
Auteurs
Membres identifiés du Cancéropôle Est :
Pr SCHAAF Pierre
Tous les auteurs :
Kelber JB, Bensalah-Ledoux A, Zahouani S, Baguenard B, Schaaf P, Chaumont A, Guy S, Jierry L
Lien Pubmed
Résumé
Tuning the dihedral angle (DA) of axially chiral compounds can impact biological activity, catalyst efficiency, molecular motor performance, or chiroptical properties. Herein, we report gradual, controlled and reversible changes in molecular conformation of a covalently linked binaphthyl moiety, within a 3D polymeric network by the application of a macroscopic stretching force. We managed a direct observation of the DA changes by measuring the circular dichroism signal of an optically pure BINOL-crosslinked elastomer network. In accordance with computed spectra, stretching the elastomer resulted in a widening of the DA between naphthyl rings when the BINOL was doubly-grafted to the elastomer network, while no effect was observed when a single naphthyl ring of the BINOL was grafted to the elastomer network. Combining both experimental and theoretical results, we have determined that ~170% extension of the elastomers led to the transfer of a mechanical force to the BINOL moiety of 2.5 kcal*mol -1 *Å -1 (~175 pN) in magnitude and results in the opening of the DA of BINOL up to ~130°.
Mots clés
Mechanochemistry * Stimulus-Responsive Materials * Conformation * Circular Dichroïsm * Chirality
Référence
Angew. Chem. Int. Ed. Engl.. 2020 Aug 28;: