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Force-Dependent Multicolor Mechanochromism from a Single Mechanophore

McFadden, Molly E. and Robb, Maxwell J. (2019) Force-Dependent Multicolor Mechanochromism from a Single Mechanophore. Journal of the American Chemical Society, 141 (29). pp. 11388-11392. ISSN 0002-7863. doi:10.1021/jacs.9b05280.

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We report a bis-naphthopyran mechanophore that exhibits force-dependent changes in visible absorption. A series of polymers incorporating a chain-centered bis-naphthopyran mechanophore was synthesized and mechanically activated using ultrasonication. By varying the length of the polymer chains, the force delivered to the mechanophore is modulated systematically. We demonstrate that the relative distribution of two distinctly colored merocyanine products is altered predictably with different magnitudes of applied force, resulting in gradient multicolor mechanochromism. The mechanochemical reactivity of bis-naphthopyran is supported by density functional theory calculations and described by a theoretical model that provides insight into the force–color relationship.

Item Type:Article
Related URLs:
URLURL TypeDescription
McFadden, Molly E.0000-0003-3174-6385
Robb, Maxwell J.0000-0002-0528-9857
Additional Information:© 2019 American Chemical Society. Received: May 16, 2019; Published: July 8, 2019. Financial support from Caltech and the Dow Next Generation Educator Fund is gratefully acknowledged. We thank Corey Husic, Anna Overholts, and Dr. Scott Virgil for helpful discussions and the Center for Catalysis and Chemical Synthesis of the Beckman Institute at Caltech for access to equipment. M.E.M. was supported by a NSF Graduate Research Fellowship (DGE-1745301). The authors declare no competing financial interest.
Funding AgencyGrant Number
Dow Next Generation Educator FundUNSPECIFIED
NSF Graduate Research FellowshipDGE‐1745301
Issue or Number:29
Record Number:CaltechAUTHORS:20190709-111608490
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Official Citation:Force-Dependent Multicolor Mechanochromism from a Single Mechanophore. Molly E. McFadden and Maxwell J. Robb. Journal of the American Chemical Society 2019 141 (29), 11388-11392. DOI: 10.1021/jacs.9b05280
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:96999
Deposited By: Tony Diaz
Deposited On:09 Jul 2019 18:42
Last Modified:16 Nov 2021 17:25

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