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Reversible Soft Mechanochemical Control of Biaryl Conformations through Crosslinking in a 3D Macromolecular Network
Author(s) -
Kelber Julien B.,
BensalahLedoux Amina,
Zahouani Sarah,
Baguenard Bruno,
Schaaf Pierre,
Chaumont Alain,
Guy Stephan,
Jierry Loïc
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202010604
Subject(s) - moiety , elastomer , macromolecule , circular dichroism , covalent bond , dihedral angle , materials science , chemistry , polymer chemistry , crystallography , molecule , stereochemistry , organic chemistry , hydrogen bond , biochemistry
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 application of a macroscopic stretching force. We managed direct observation of DA changes by measuring the circular dichroism signal of an optically pure BINOL‐crosslinked elastomer network. Stretching the elastomer resulted in a widening of the DA between naphthyl rings when the BINOL was doubly grafted to the elastomer network; no effect was observed when a single naphthyl ring of the BINOL was grafted to the elastomer network. We have determined that ca. 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 (ca. 175 pN) in magnitude and results in the opening of the DA of BINOL up to 130°.