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Shielding effects in spacious macromolecules: a case study with dendronized polymers

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Abstract

Dendronized polymers exhibit defined structures with bulky side chains (dendrons) on a linear polymer backbone. Upon reaction with radicals, chromophores close to the backbone were bleached. The reaction rate and yield decreased with increasing dendron size, demonstrating that the inside of dendronized polymers can be “shielded” by bulky dendrons from access by reactive species.

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  12. Alternatively to the reduction, also a radical addition to the nitro group is possible.13 Our data and interpretation do not depend on the exact mechanism as both reactions will cause bleaching of the chromophore.

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  18. PG3 and l-PG3 are not part of a strictly homologous series. In fact they differ in the chain length and polydispersity index (PDI) (n ofPG3 ≈ 650, n of l-PG3 ≈ 700, see Table S1). Their different initial responses on exposure to iPrOH• (0-10 μs after pulse) may originate from such physical differences.

  19. It is also conceivable that iPrOH• may add to the nitro group of the chromophore before reduction.13 Such an addition process would favour repair in the bulk solution even more.

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Authors and Affiliations

  1. Department of Materials, Laboratory of Polymer Chemistry, Vladimir-Prelog Weg 5, CH-8093, Zürich, Switzerland

    Chiara Gstrein, Peter Walde & A. Dieter Schlüter

  2. Department of Chemistry and Applied Biosciences, Laboratory of Inorganic Chemistry, Vladimir-Prelog Weg 1; ETH Zürich, CH-8093, Zürich, Switzerland

    Thomas Nauser

Authors
  1. Chiara Gstrein
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  2. Peter Walde
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  3. A. Dieter Schlüter
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  4. Thomas Nauser
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Correspondence to Thomas Nauser.

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Electronic supplementary information (ESI) available. See DOI: 10.1039/c6pp00191b.

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Gstrein, C., Walde, P., Schlüter, A.D. et al. Shielding effects in spacious macromolecules: a case study with dendronized polymers. Photochem Photobiol Sci 15, 964–968 (2016). https://doi.org/10.1039/c6pp00191b

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  • DOI: https://doi.org/10.1039/c6pp00191b

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