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Mechanically gated formation of donor–acceptor Stenhouse adducts enabling mechanochemical multicolour soft lithography

Nature Chemistry volume 15, pages 332–338 (2023)Cite this article

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Abstract

Stress-sensitive molecules called mechanophores undergo productive chemical transformations in response to mechanical force. A variety of mechanochromic mechanophores, which change colour in response to stress, have been developed, but modulating the properties of the dyes generally requires the independent preparation of discrete derivatives. Here we introduce a mechanophore platform enabling mechanically gated multicolour chromogenic reactivity. The mechanophore is based on an activated furan precursor to donor–acceptor Stenhouse adducts (DASAs) masked as a hetero-Diels–Alder adduct. Mechanochemical activation of the mechanophore unveils the DASA precursor, and subsequent reaction with a secondary amine generates an intensely coloured DASA. Critically, the properties of the DASA are controlled by the amine, and thus a single mechanophore can be differentiated post-activation to produce a wide range of functionally diverse DASAs. We highlight this system by establishing the concept of mechanochemical multicolour soft lithography whereby a complex multicolour composite image is printed into a mechanochemically active elastomer through an iterative process of localized compression followed by reaction with different amines.

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Fig. 1: Evolution in the design of mechanochromic mechanophores and a platform enabling mechanically gated DASA formation.
Fig. 2: Synthesis of linear poly(methyl acrylate) polymers containing the masked DASA precursor at the chain midpoint (PMA-1) and at the chain end (PMA-Control) for ultrasonication experiments.
Fig. 3: Characterization of mechanically gated DASA formation via solution-phase ultrasonication.
Fig. 4: Solid-state mechanophore activation in elastomeric PDMS materials and demonstration of mechanochemical multicolour lithography.

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Data availability

All data are available in the manuscript or the Supplementary Information. Experimental data and characterization data for all new compounds prepared in the course of these studies are provided in the Supplementary Information of this paper. The X-ray crystallographic coordinates for compound (±)-3 have been deposited at the Cambridge Crystallographic Data Center (CCDC) with deposition no. 2163133. These data can be obtained free of charge from the CCDC via www.ccdc.cam.ac.uk/structures/. Source data are provided with this paper.

References

  1. Caruso, M. M. et al. Mechanically-induced chemical changes in polymeric materials. Chem. Rev. 109, 5755–5798 (2009).

    Article  CAS  PubMed  Google Scholar 

  2. Beyer, M. K. & Clausen-Schaumann, H. Mechanochemistry: the mechanical activation of covalent bonds. Chem. Rev. 105, 2921–2948 (2005).

    Article  CAS  PubMed  Google Scholar 

  3. Li, J., Nagamani, C. & Moore, J. S. Polymer mechanochemistry: from destructive to productive. Acc. Chem. Res. 48, 2181–2190 (2015).

    Article  CAS  PubMed  Google Scholar 

  4. Berkowski, K. L., Potisek, S. L., Hickenboth, C. R. & Moore, J. S. Ultrasound-induced site-specific cleavage of azo-functionalized poly(ethylene glycol). Macromolecules 38, 8975–8978 (2005).

    Article  CAS  Google Scholar 

  5. Kim, G. et al. High-intensity focused ultrasound-induced mechanochemical transduction in synthetic elastomers. Proc. Natl Acad. Sci. USA 116, 10214–10222 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  6. Davis, D. A. et al. Force-induced activation of covalent bonds in mechanoresponsive polymeric materials. Nature 459, 68–72 (2009).

    Article  CAS  PubMed  Google Scholar 

  7. Gossweiler, G. R. et al. Mechanochemical activation of covalent bonds in polymers with full and repeatable macroscopic shape recovery. ACS Macro Lett. 3, 216–219 (2014).

    Article  CAS  PubMed  Google Scholar 

  8. Kingsbury, C. M. et al. Shear activation of mechanophore-crosslinked polymers. J. Mater. Chem. 21, 8381–8388 (2011).

    Article  CAS  Google Scholar 

  9. Versaw, B. A., Zeng, T., Hu, X. & Robb, M. J. Harnessing the power of force: development of mechanophores for molecular release. J. Am. Chem. Soc. 143, 21461–21473 (2021).

    Article  CAS  PubMed  Google Scholar 

  10. Chen, Z. et al. Mechanochemical unzipping of insulating polyladderene to semiconducting polyacetylene. Science 357, 475–479 (2017).

    Article  CAS  PubMed  Google Scholar 

  11. Ramirez, A. L. B. et al. Mechanochemical strengthening of a synthetic polymer in response to typically destructive shear forces. Nat. Chem. 5, 757–761 (2013).

    Article  CAS  PubMed  Google Scholar 

  12. Ghanem, M. A. et al. The role of polymer mechanochemistry in responsive materials and additive manufacturing. Nat. Rev. Mater. 6, 84–98 (2020).

    Article  Google Scholar 

  13. Chen, Y., Mellot, G., van Luijk, D., Creton, C. & Sijbesma, R. P. Mechanochemical tools for polymer materials. Chem. Soc. Rev. 50, 4100–4140 (2021).

    Article  CAS  PubMed  Google Scholar 

  14. Hu, X., McFadden, M. E., Barber, R. W. & Robb, M. J. Mechanochemical regulation of a photochemical reaction. J. Am. Chem. Soc. 140, 14073–14077 (2018).

    Article  CAS  PubMed  Google Scholar 

  15. Barber, R. W. & Robb, M. J. A modular approach to mechanically gated photoswitching with color-tunable molecular force probes. Chem. Sci. 12, 11703–11709 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  16. Kim, T. A., Robb, M. J., Moore, J. S., White, S. R. & Sottos, N. R. Mechanical reactivity of two different spiropyran mechanophores in polydimethylsiloxane. Macromolecules 51, 9177–9183 (2018).

    Article  CAS  Google Scholar 

  17. Lin, Y., Barbee, M. H., Chang, C.-C. & Craig, S. L. Regiochemical effects on mechanophore activation in bulk materials. J. Am. Chem. Soc. 140, 15969–15975 (2018).

    Article  CAS  PubMed  Google Scholar 

  18. Helmy, S. et al. Photoswitching using visible light: a new class of organic photochromic molecules. J. Am. Chem. Soc. 136, 8169–8172 (2014).

    Article  CAS  PubMed  Google Scholar 

  19. Balamurugan, A. & Lee, H. A visible light responsive on–off polymeric photoswitch for the colorimetric detection of nerve agent mimics in solution and in the vapor phase. Macromolecules 49, 2568–2574 (2016).

    Article  CAS  Google Scholar 

  20. Diaz, Y. J. et al. A versatile and highly selective colorimetric sensor for the detection of amines. Chem. Eur. J. 23, 3562–3566 (2017).

    Article  CAS  PubMed  Google Scholar 

  21. Chen, Q. et al. Stable activated furan and donor–acceptor Stenhouse adduct polymer conjugates as chemical and thermal sensors. Macromolecules 52, 4370–4375 (2019).

    Article  CAS  Google Scholar 

  22. Poelma, S. O. et al. Controlled drug release to cancer cells from modular one-photon visible light-responsive micellar system. Chem. Commun. 52, 10525–10528 (2016).

    Article  CAS  Google Scholar 

  23. Lee, J. et al. Tunable photothermal actuation enabled by photoswitching of donor–acceptor Stenhouse adducts. ACS Appl. Mater. Interfaces 12, 54075–54082 (2020).

    Article  CAS  Google Scholar 

  24. Helmy, S., Oh, S., Leibfarth, F. A., Hawker, C. J. & Read de Alaniz, J. Design and synthesis of donor–acceptor Stenhouse adducts: a visible light photoswitch derived from furfural. J. Org. Chem. 79, 11316–11329 (2014).

    Article  CAS  PubMed  Google Scholar 

  25. Hemmer, J. R. et al. Controlling dark equilibria and enhancing donor–acceptor Stenhouse adduct photoswitching properties through carbon acid design. J. Am. Chem. Soc. 140, 10425–10429 (2018).

    Article  CAS  PubMed  Google Scholar 

  26. Lerch, M. M., Szymański, W. & Feringa, B. L. The (photo)chemistry of Stenhouse photoswitches: guiding principles and system design. Chem. Soc. Rev. 47, 1910–1937 (2018).

    Article  CAS  PubMed  Google Scholar 

  27. Pałasz, A. & Pałasz, T. Knoevenagel condensation of cyclic ketones with benzoylacetonitrile and N,N′-dimethylbarbituric acid. Application of sterically hindered condensation products in the synthesis of spiro and dispiropyrans by hetero-Diels–Alder reactions. Tetrahedron 67, 1422–1431 (2011).

    Article  Google Scholar 

  28. Stevenson, R. & De Bo, G. Controlling reactivity by geometry in retro-Diels–Alder reactions under tension. J. Am. Chem. Soc. 139, 16768–16771 (2017).

    Article  CAS  PubMed  Google Scholar 

  29. Beyer, M. K. The mechanical strength of a covalent bond calculated by density functional theory. J. Chem. Phys. 112, 7307–7312 (2000).

    Article  CAS  Google Scholar 

  30. Klein, I. M., Husic, C. C., Kovács, D. P., Choquette, N. J. & Robb, M. J. Validation of the CoGEF method as a predictive tool for polymer mechanochemistry. J. Am. Chem. Soc. 142, 16364–16381 (2020).

    Article  CAS  PubMed  Google Scholar 

  31. Clerc, M. et al. Promoting the furan ring-opening reaction to access new donor–acceptor Stenhouse adducts with hexafluoroisopropanol. Angew. Chem. Int. Ed. 60, 10219–10227 (2021).

  32. Clerc, M. et al. Donor–acceptor Stenhouse adduct-polydimethylsiloxane-conjugates for enhanced photoswitching in bulk polymers. Macromol. Rapid Commun. 43, 2200120 (2022).

    Article  CAS  Google Scholar 

  33. Sroda, M. M., Stricker, F., Peterson, J. A., Bernal, A. & Read de Alaniz, J. Donor–acceptor Stenhouse adducts: exploring the effects of ionic character. Chem. Eur. J. 27, 4183–4190 (2021).

    Article  CAS  PubMed  Google Scholar 

  34. Lui, B. F. et al. Unusual concentration dependence of the photoisomerization reaction in donor–acceptor Stenhouse adducts. Photochem. Photobiol. Sci. 18, 1587–1595 (2019).

    Article  CAS  PubMed  Google Scholar 

  35. Xia, Y. & Whitesides, G. M. Soft lithography. Angew. Chem. Int. Ed. 37, 550–575 (1998).

  36. Mei, Y. et al. Mechanochemical lithography. J. Am. Chem. Soc. 144, 9949–9958 (2022).

    Article  CAS  PubMed  Google Scholar 

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Acknowledgements

Financial support from Caltech is gratefully acknowledged. A.C.O. was supported by a National Science Foundation Graduate Research Fellowship (DGE-1745301) and an Institute Fellowship from Caltech. We thank M. Shahgholi for technical assistance with mass spectrometry and M. Takase for assistance with X-ray crystallography.

Author information

Authors and Affiliations

  1. Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA

    Anna C. Overholts, Wendy Granados Razo & Maxwell J. Robb

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  1. Anna C. Overholts
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  2. Wendy Granados Razo
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Contributions

M.J.R. conceptualized the project and provided guidance during all stages. A.C.O. and M.J.R. designed the research. A.C.O. and W.G.R. performed the experiments. A.C.O., W.G.R. and M.J.R. analysed the data. A.C.O. and M.J.R. wrote the paper.

Corresponding author

Correspondence to Maxwell J. Robb.

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Competing interests

A.C.O. and M.J.R. are inventors on a US provisional patent application submitted by California Institute of Technology (CIT 8808-P) covering the chemistry and lithographic process disclosed herein.

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Nature Chemistry thanks the anonymous reviewers for their contribution to the peer review of this work.

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Supplementary information

Supplementary Information

Supplementary Figs. 1–30, Tables 1 and 2, and Discussion.

Supplementary Data 1

Crystallographic data for compound (±)-3; CCDC reference no. 2163133.

Supplementary Data 2

The XYZ coordinates for the DFT calculations.

Source data

Source Data Fig. 1

Source data for CoGEF plot.

Source Data Fig. 3

Source data for UV–vis spectra.

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Overholts, A.C., Granados Razo, W. & Robb, M.J. Mechanically gated formation of donor–acceptor Stenhouse adducts enabling mechanochemical multicolour soft lithography. Nat. Chem. 15, 332–338 (2023). https://doi.org/10.1038/s41557-022-01126-5

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