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Generation of an Elusive Permanent Merocyanine via a Unique Mechanochemical Reaction Pathway

McFadden, Molly E. and Robb, Maxwell J. (2021) Generation of an Elusive Permanent Merocyanine via a Unique Mechanochemical Reaction Pathway. Journal of the American Chemical Society, 143 (21). pp. 7925-7929. ISSN 0002-7863. doi:10.1021/jacs.1c03865.

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We report the discovery of a 2H-naphtho[1,2-b]pyran mechanophore that produces a permanent merocyanine dye upon mechanochemical activation, in contrast to the reversible product generated photochemically. Experiments suggest that the irreversibility of the mechanically generated merocyanine is due to a unique reaction in which the scission of an ester C–O bond reveals a β-hydroxy ketone that locks the merocyanine through an intramolecular H-bonding interaction. In addition to demonstrating the reactivity using solution-phase ultrasonication, permanent merocyanine generation is also achieved in solid polymeric materials. The permanent coloration achieved with the naphthopyran mechanophore affords unique opportunities for sensing and force-recording applications as well as fundamental studies limited by the reversibility of typical colorimetric force probes.

Item Type:Article
Related URLs:
URLURL TypeDescription
McFadden, Molly E.0000-0003-3174-6385
Robb, Maxwell J.0000-0002-0528-9857
Additional Information:© 2021 American Chemical Society. Received 13 April 2021. Published online 19 May 2021. Financial support from Caltech is gratefully acknowledged. M.E.M. was supported by an NSF Graduate Research Fellowship (DGE-1745301). We thank the Molecular Materials Research Center and the Center for Catalysis and Chemical Synthesis of the Beckman Institute at Caltech for access to equipment. We also thank Dr. Bruce Brunschwig, Dr. Mona Shahgholi, and Dr. David VanderVelde for technical assistance. The authors declare no competing financial interest.
Funding AgencyGrant Number
NSF Graduate Research FellowshipDGE-1745301
Subject Keywords:Dyes and pigments, Organic compounds, Materials, Irradiation, Polymers
Issue or Number:21
Record Number:CaltechAUTHORS:20210520-113955890
Persistent URL:
Official Citation:Generation of an Elusive Permanent Merocyanine via a Unique Mechanochemical Reaction Pathway. Molly E. McFadden and Maxwell J. Robb. Journal of the American Chemical Society 2021 143 (21), 7925-7929; DOI: 10.1021/jacs.1c03865
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:109198
Deposited By: George Porter
Deposited On:24 May 2021 14:27
Last Modified:03 Jun 2021 21:11

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