biostudies-literatureThazhathethil SFoundation for Promotion of Material Science and Technology of JapanAdolphe Merkle FoundationCore Research for Evolutional Science and TechnologyFusion Oriented REsearch for disruptive Science and TechnologyMurata Science FoundationNational Center of Competence in Research Bio-Inspired Materials, University of Fribourge202209225https://www.ebi.ac.uk/biostudies/studies/S-EPMC9804172biostudies-literatureUnknown61(42)Mechanochromic mechanophores are reporter molecules that indicate mechanical events through changes of their photophysical properties. Supramolecular mechanophores in which the activation is based on the rearrangement of luminophores and/or quenchers without any covalent bond scission, remain less well investigated. Here, we report a cyclophane-based supramolecular mechanophore that contains a 1,6-bis(phenylethynyl)pyrene luminophore and a pyromellitic diimide quencher. In solution, the blue monomer emission of the luminophore is largely quenched and a faint reddish-orange emission originating from a charge-transfer (CT) complex is observed. A polyurethane elastomer containing the mechanophore displays orange emission in the absence of force, which is dominated by the CT-emission. MechanicAngewandte Chemie (International ed. in English)Excited State Charge-Transfer Complexes Enable Fluorescence Color Changes in a Supramolecular Cyclophane Mechanophore.PMC9804172JPMJPR17P651NF40-182881JP18H02024JPMJFR201NMuramatsu TThazhathethil STamaoki NSagara YWeder CfalseExcited State Charge-Transfer Complexes Enable Fluorescence Color Changes in a Supramolecular Cyclophane Mechanophore.Mechanochromic mechanophores are reporter molecules that indicate mechanical events through changes of their photophysical properties. Supramolecular mechanophores in which the activation is based on the rearrangement of luminophores and/or quenchers without any covalent bond scission, remain less well investigated. Here, we report a cyclophane-based supramolecular mechanophore that contains a 1,6-bis(phenylethynyl)pyrene luminophore and a pyromellitic diimide quencher. In solution, the blue monomer emission of the luminophore is largely quenched and a faint reddish-orange emission originating from a charge-transfer (CT) complex is observed. A polyurethane elastomer containing the mechanophore displays orange emission in the absence of force, which is dominated by the CT-emission. Mechanic2022-01-01T00:00:00Z2022 Oct2026-03-16T08:08:11.784Z2025-04-05T12:09:40.163ZS-EPMC98041723595026010.1002/anie.202209225