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Folded Perylene Diimide Loops as Mechanoresponsive Motifs
Author(s) -
Traeger Hanna,
Sagara Yoshimitsu,
Kiebala Derek J.,
Schrettl Stephen,
Weder Christoph
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202105219
Subject(s) - excimer , perylene , diimide , intramolecular force , moiety , photochemistry , polymer , intermolecular force , fluorescence , materials science , acrylate , supramolecular chemistry , supramolecular polymers , polymer chemistry , chemistry , molecule , stereochemistry , copolymer , organic chemistry , optics , physics , composite material
A supramolecular mechanophore that can be integrated into polymers and indicates deformation by a fluorescence color change is reported. Two perylene diimides (PDIs) were connected by a short spacer and equipped with peripheral atom transfer polymerization initiators. In the idle state, the motif folds into a loop and its emission is excimer dominated. Poly(methyl acrylate) (PMA) chains were grown from the motif and the mechanophore‐containing polymer was blended with unmodified PMA to afford materials that display a visually discernible fluorescence color change upon deformation, which causes the loops to unfold. The response is instant, and correlates linearly with the applied strain. Experiments with a reference polymer containing only one PDI moiety show that looped mechanophores that display intramolecular excimer formation offer considerable advantages over intermolecular dye aggregates, including a concentration‐independent response, direct signaling of mechanical processes, and a more pronounced optical change.