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A photoswitchable catalyst system for remote-controlled (co)polymerization in situ

Nature Catalysisvolume 1pages516522 (2018) | Download Citation


The fundamental properties of a polymeric material are ultimately governed by its structure, which mainly relies on monomer composition and connection, topology, chain length, and polydispersity. Thus far, these structural characteristics are typically set ex situ by the specific polymerization procedure, eventually limiting the future design space for the creation of more sophisticated polymers. Herein, we report on a single photoswitchable catalyst system, which enables in situ remote control over the ring-opening polymerization of l-lactide and further allows regulation of the incorporation of trimethylene carbonate and δ-valerolactone monomers in copolymerizations. By implementing a phenol moiety into a diarylethene-type structure, we exploit light-induced keto–enol tautomerism to switch the hydrogen-bonding-mediated monomer activation reversibly ON and OFF. This general and versatile principle allows for exquisite external modulation of ground-state catalysis of a living polymerization process in a closed system by ultraviolet and visible light and should thereby facilitate the generation of new polymer structures.

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F.E. and M.K. are indebted to the Fonds der Chemischen Industrie and Studienstiftung des deutschen Volkes, respectively, for providing doctoral fellowships. Generous support from the European Research Council via ERC-2012-STG_308117 (Light4Function) is gratefully acknowledged.

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Author notes

  1. These authors contributed equally: Fabian Eisenreich, Michael Kathan.


  1. Department of Chemistry, IRIS Adlershof der Humboldt-Universität zu Berlin, Berlin, Germany

    • Fabian Eisenreich
    • , Michael Kathan
    • , Andre Dallmann
    • , Svante P. Ihrig
    • , Timm Schwaar
    • , Bernd M. Schmidt
    •  & Stefan Hecht
  2. Protein Analysis Division, Federal Institute for Materials Research and Testing, Berlin, Germany

    • Timm Schwaar
  3. Institute of Organic and Macromolecular Chemistry, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany

    • Bernd M. Schmidt


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F.E., M.K. and S.P.I. synthesized diarylethene 1. F.E. conducted ultraviolet visible spectroscopy and polymerization experiments, and analysed polymers via NMR and GPC measurements. F.E. and A.D. performed kinetics studies of polymerizations via NMR spectroscopy. T.S. conducted MALDI-MS measurements. B.M.S. solved the single-crystal X-ray structure. F.E., M.K. and S.H. conceived the idea, designed the study and wrote the manuscript. All authors discussed the results and edited the manuscript.

Competing interests

The authors declare no competing interests.

Corresponding author

Correspondence to Stefan Hecht.

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    Supplementary Methods, Supplementary Figures 1–48, Supplementary References

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