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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 international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.202010604
Subject(s) - moiety , elastomer , macromolecule , circular dichroism , covalent bond , dihedral angle , materials science , optically active , polymer chemistry , chemistry , crystallography , molecule , stereochemistry , organic chemistry , composite material , hydrogen bond , biochemistry
Abstract 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°.