Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Highly efficient organic photocatalysts discovered via a computer-aided-design strategy for visible-light-driven atom transfer radical polymerization

Abstract

Organocatalysed photoredox-mediated atom transfer radical polymerization (O-ATRP) is a very promising polymerization method as it eliminates concerns associated with transition-metal contamination of polymer products. However, reducing the amount of catalyst and expanding the monomer scope remain major challenges in O-ATRP. Herein, we report a systematic computer-aided-design strategy to identify powerful visible-light photoredox catalysts for O-ATRP. One of our discovered organic photoredox catalysts controls the polymerization of methyl methacrylate at sub-ppm catalyst loadings (0.5 ppm—a very meaningful amount enabling the direct use of polymers without a catalyst removal process); that is, 100–1,000 times lower loadings than other organic photoredox catalysts reported so far. Another organic photoredox catalyst with supra-reducing power in an excited state and high redox stability facilitates the challenging polymerization of the non-acrylic monomer styrene, which is not successful using existing photoredox catalysts. This work provides access to diverse challenging organic/polymer syntheses and makes O-ATRP viable for many industrial and biomedical applications.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Fig. 1: Strategy for OPC design.
Fig. 2: Molecular structures of OPCs.
Fig. 3: Analyses of the photophysical and electrochemical properties of OPCs.
Fig. 4: Photophysical and electrochemical properties of 2c.
Fig. 5: Photophysical and electrochemical properties of 4g.

Data availability

The data that support the findings of this study are available within the article and its Supplementary Information, and from the corresponding author upon reasonable request.

References

  1. 1.

    Matyjaszewski, K. Advanced materials by atom transfer radical polymerization. Adv. Mater. 30, 1706441 (2018).

    Article  Google Scholar 

  2. 2.

    Matyjaszewski, K. & Tsarevsky, N. V. Macromolecular engineering by atom transfer radical polymerization. J. Am. Chem. Soc. 136, 6513–6533 (2014).

    CAS  Article  Google Scholar 

  3. 3.

    Corrigan, N., Shamugam, S., Xu, J. & Boyer, C. Photocatalysis in organic polymer synthesis. Chem. Soc. Rev. 45, 6165–6212 (2016).

    CAS  Article  Google Scholar 

  4. 4.

    Pan, X. et al. Photomediated controlled radical polymerization. Prog. Polymer Sci. 62, 73–125 (2016).

    CAS  Article  Google Scholar 

  5. 5.

    Shanmugam, S. & Boyer, C. Organic photocatalysts for cleaner polymer synthesis. Science 352, 1053–1054 (2016).

    CAS  Article  Google Scholar 

  6. 6.

    Theriot, J. C., McCarthy, B. G., Lim, C. H. & Miyake, G. M. Organocatalyzed atom transfer radical polymerization: perspectives on catalyst design and performance. Macromol. Rapid Commun. 38, 1700040 (2017).

    Article  Google Scholar 

  7. 7.

    Treat, N. J. et al. Metal-free atom transfer radical polymerization. J. Am. Chem. Soc. 136, 16096–16101 (2014).

    CAS  Article  Google Scholar 

  8. 8.

    Pan, X. et al. Mechanism of photoinduced metal-free atom transfer radical polymerization: experimental and computational studies. J. Am. Chem. Soc. 138, 2411–2425 (2016).

    CAS  Article  Google Scholar 

  9. 9.

    Theriot, J. C. et al. Organocatalyzed atom transfer radical polymerization driven by visible light. Science 352, 1082–1086 (2016).

    CAS  Article  Google Scholar 

  10. 10.

    Pearson, R. M., Lim, C. H., McCarthy, B. G., Musgrave, C. B. & Miyake, G. M. Organocatalyzed atom transfer radical polymerization using N-aryl phenoxazines as photoredox catalysts. J. Am. Chem. Soc. 138, 11399–11407 (2016).

    CAS  Article  Google Scholar 

  11. 11.

    Lim, C. H. et al. Intramolecular charge transfer and ion pairing in N,N-diaryl dihydrophenazine photoredox catalysts for efficient organocatalyzed atom transfer radical polymerization. J. Am. Chem. Soc. 139, 348–355 (2017).

    CAS  Article  Google Scholar 

  12. 12.

    McCarthy, B. G. et al. Structure–property relationships for tailoring phenoxazines as reducing photoredox catalysts. J. Am. Chem. Soc. 140, 5088–5101 (2018).

    CAS  Article  Google Scholar 

  13. 13.

    Sartor, S. M., McCarthy, B. G., Pearson, R. M., Miyake, G. M. & Damrauer, N. H. Exploiting charge-transfer states for maximizing intersystem crossing yields in organic photoredox catalysts. J. Am. Chem. Soc. 140, 4778–4781 (2018).

    CAS  Article  Google Scholar 

  14. 14.

    Ghosh, I., Ghosh, T., Bardagi, J. I. & Konig, B. Reduction of aryl halides by consecutive visible light-induced electron transfer processes. Science 346, 725–728 (2014).

    CAS  Article  Google Scholar 

  15. 15.

    Murphy, J. J. et al. Asymmetric catalytic formation of quaternary carbons by iminium ion trapping of radicals. Nature 532, 218–222 (2016).

    CAS  Article  Google Scholar 

  16. 16.

    Silvi, M., Verrier, C., Rey, Y. P., Buzzetti, L. & Melchiorre, P. Visible-light excitation of iminium ions enables the enantioselective catalytic β-alylation of enals. Nat. Chem. 9, 868–873 (2017).

    CAS  Article  Google Scholar 

  17. 17.

    Pandey, G. & Laha, R. Visible-light-catalyzed direct benzylic C(sp 3)–H amination reaction by cross-dehydrogenative coupling. Angew. Chem. Int. Ed. 54, 14875–14879 (2015).

    CAS  Article  Google Scholar 

  18. 18.

    Rybicka-Jasinska, K., Shan, W., Zawada, K., Kadish, K. M. & Gryko, D. Porphyrins as photoredox catalysts: experimental and theoretical studies. J. Am. Chem. Soc. 138, 15451–15458 (2016).

    CAS  Article  Google Scholar 

  19. 19.

    Wang, L. et al. Structural design principle of small-molecule organic semiconductors for metal-free, visible-light-promoted photocatalysis. Angew. Chem. Int. Ed. 55, 9783–9787 (2016).

    CAS  Article  Google Scholar 

  20. 20.

    Luo, J. & Zhang, J. Donor–acceptor fluorophores for visible-light-promoted organic synthesis: photoredox/Ni dual catalytic C(sp 3)–C(sp 2) cross-coupling. ACS Catal. 6, 873–877 (2016).

    CAS  Article  Google Scholar 

  21. 21.

    Poelma, S. O. et al. Chemoselective radical dehalogenation and C–C bond formation on aryl halide substrates using organic photoredox catalysts. J. Org. Chem. 81, 7155–7160 (2016).

    CAS  Article  Google Scholar 

  22. 22.

    Kottisch, V., Michaudel, Q. & Fors, B. P. Cationic polymerization of vinyl ethers controlled by visible light. J. Am. Chem. Soc. 138, 15535–15538 (2016).

    CAS  Article  Google Scholar 

  23. 23.

    Kottisch, V., Supej, M. J. & Fors, B. P. Enhancing temporal control and enabling chain‐end modification in photoregulated cationic polymerizations by using Ir‐based catalysts. Angew. Chem. Int. Ed. 57, 8260–8264 (2018).

    CAS  Article  Google Scholar 

  24. 24.

    Arias-Rotondo, D. M. & McCusker, J. K. The photophysics of photoredox catalysis: a roadmap for catalyst design. Chem. Soc. Rev. 45, 5803–5820 (2016).

    CAS  Article  Google Scholar 

  25. 25.

    Dumur, F., Gigmes, D., Fouassier, J. & Lalevee, J. Organic electronics: an El Dorado in the quest of new photocatalysts for polymerization reactions. Acc. Chem. Res. 49, 1980–1989 (2016).

    CAS  Article  Google Scholar 

  26. 26.

    Majek, M. & Wangelin, A. J. Mechanistic perspectives on organic photoredox catalysis for aromatic substitutions. Acc. Chem. Res. 49, 2316–2327 (2016).

    CAS  Article  Google Scholar 

  27. 27.

    Romero, N. A. & Nicewicz, D. A. Organic photoredox catalysis. Chem. Rev. 116, 10075–10166 (2016).

    CAS  Article  Google Scholar 

  28. 28.

    Hirata, S. Recent advances in materials with room-temperature phosphorescence: photophysics for triplet exciton stabilization. Adv. Opt. Mater. 5, 1700116 (2017).

    Article  Google Scholar 

  29. 29.

    El-Sayed, M. A. The triplet state: its radiative and non-radiative properties. Acc. Chem. Res. 1, 8–16 (1968).

    CAS  Article  Google Scholar 

  30. 30.

    Turro, N. J. The triplet state. J. Chem. Educ. 46, 2–6 (1969).

    CAS  Article  Google Scholar 

  31. 31.

    Bolton, O., Lee, K., Kim, H. J., Lin, K. Y. & Kim, J. Activating efficient phosphorescence from purely organic materials by crystal design. Nat. Chem. 3, 205–210 (2011).

    CAS  Article  Google Scholar 

  32. 32.

    Kwon, M. S. et al. Suppressing molecular motions for enhanced room-temperature phosphorescence of metal-free organic materials. Nat. Commun. 6, 8947 (2015).

    Article  Google Scholar 

  33. 33.

    Zhang, G., Palmer, G. M., Dewhirst, M. W. & Fraser, C. L. A dual-emissive-materials design concept enables tumour hypoxia imaging. Nat. Mater. 8, 747–751 (2009).

    CAS  Article  Google Scholar 

  34. 34.

    El-Sayed, M. A. Spin–orbit coupling and the radiationless processes in nitrogen heterocyclics. J. Chem. Phys. 38, 2834–2838 (1963).

    CAS  Article  Google Scholar 

  35. 35.

    Flamigni, L. et al. Photochemistry and photophysics of coordination compounds: iridium. Top. Curr. Chem. 21, 143–203 (2007).

    Article  Google Scholar 

  36. 36.

    Kalyanasundaram, K. Photophysics, photochemistry and solar energy conversion with tris(bipyridyl)ruthenium(ii) and its analogues. Coord. Chem. Rev. 46, 159–244 (1982).

    CAS  Article  Google Scholar 

  37. 37.

    Fukuzumi, S. et al. Electron-transfer state of 9-mesityl-10-methylacridinium ion with a much longer lifetime and higher energy than that of the natural photosynthetic reaction center. J. Am. Chem. Soc. 126, 1600–1601 (2004).

    CAS  Article  Google Scholar 

  38. 38.

    Uoyama, H., Goushi, K., Shizu, K., Nomura, H. & Adachi, C. Highly efficient organic light emitting diodes from delayed fluorescence. Nature 492, 234–238 (2012).

    CAS  Article  Google Scholar 

  39. 39.

    Milián-Medina, B. & Gierschner, J. Computational design of low singlet–triplet gap all organic molecules for OLED application. Org. Elec. 13, 985–991 (2012).

    Article  Google Scholar 

  40. 40.

    Bombarelli, R. G. et al. Design of efficient molecular organic light-emitting diodes by a high-throughput virtual screening and experimental approach. Nat. Mater. 15, 1120–1127 (2016).

    Article  Google Scholar 

  41. 41.

    Kucur, E., Riegler, J., Urban, G. A. & Nann, T. Determination of quantum confinement in CdSe nanocrystals by cyclic voltammetry. J. Chem. Phys. 119, 2333–2337 (2003).

    CAS  Article  Google Scholar 

  42. 42.

    Zhang, G. & Musgrave, C. B. Comparison of DFT methods for molecular orbital eigenvalue calculations. J. Phys. Chem. C 111, 1554–1561 (2007).

    CAS  Article  Google Scholar 

  43. 43.

    Coote, M. L., Lin, C. Y., Beckwith, A. L. J. & Zavitsas, A. A. A comparison of methods for measuring relative radical stabilities of carbon-centered radicals. Phys. Chem. Chem. Phys. 12, 9597–9610 (2010).

    CAS  Article  Google Scholar 

  44. 44.

    Savéant, J. M. A simple model for the kinetics of dissociative electron transfer in polar solvents. Application to the homogeneous and heterogeneous reduction of alkyl halides. J. Am. Chem. Soc. 109, 6788–6795 (1987).

    Article  Google Scholar 

  45. 45.

    Isse, A. A. et al. Mechanism of carbon–halogen bond reductive cleavage in activated alkyl halide initiators relevant to living radical polymerization: theoretical and experimental study. J. Am. Chem. Soc. 133, 6254–6264 (2011).

    CAS  Article  Google Scholar 

  46. 46.

    Kuhlmann, R. & Schnablel, W. Laser flash photolysis investigations on primary processes of the sensitized polymerization of vinyl monomers: 1. Experiments with benzophenone. Polymer 17, 419–422 (1976).

    CAS  Article  Google Scholar 

  47. 47.

    Wan, J. & Nakatsuji, H. Theoretical study of the singlet and triplet vertical electronic transitions of styrene by the symmetry adapted cluster–configuration interaction method. Chem. Phys. 302, 125–134 (2004).

    CAS  Article  Google Scholar 

  48. 48.

    Saltiel, J., Charlton, J. L. & Mueller, W. B. Nonvertical excitation transfer. Activation parameters for endothermic triplet–triplet energy transfer to the stilbenes. J. Am. Chem. Soc. 101, 1347–1348 (1979).

    CAS  Article  Google Scholar 

  49. 49.

    Miyake, G. M. & Theriot, J. C. Perylene as organic photocatalyst for the radical polymerization of functionalized vinyl monomers through oxidative quenching with alkyl bromides and visible light. Macromolecules 47, 8255–8261 (2014).

    CAS  Article  Google Scholar 

  50. 50.

    Pier, C. K., Rankic, D. A. & MacMillan, D. W. C. Visible light photoredox catalysis with transition metal complexes: application in organic synthesis. Chem. Rev. 113, 5322–5363 (2013).

    Article  Google Scholar 

  51. 51.

    Narayanam, J. M. R. & Stephenson, C. R. J. Visible light photoredox catalysis: applications in organic synthesis. Chem. Soc. Rev. 40, 102–113 (2011).

    CAS  Article  Google Scholar 

  52. 52.

    Yoon, T. P., Ischay, M. A. & Du, J. Visible light photocatalysis as a greener approach to photochemical synthesis. Nat. Chem. 2, 527–532 (2010).

    CAS  Article  Google Scholar 

  53. 53.

    Fagnoni, M., Dondi, D., Ravelli, D. & Albini, A. Photocatalysis for the formation of the C–C bond. Chem. Rev. 107, 2725–2756 (2007).

    CAS  Article  Google Scholar 

  54. 54.

    Marin, M. L., Santos-Juanes, L., Arques, A., Amat, A. M. & Miranda, M. A. Organic photocatalysts for the oxidation of pollutants and model compounds. Chem. Rev. 112, 1710–1750 (2012).

    CAS  Article  Google Scholar 

  55. 55.

    Fukuzumi, S. & Ohkubo, K. Selective photocatalytic reactions with organic photocatalysts. Chem. Sci. 4, 561–574 (2013).

    CAS  Article  Google Scholar 

  56. 56.

    Frisch, M. J. et al. Gaussian 09 Revision D.01 (Gaussian, 2009).

Download references

Acknowledgements

This work was supported by the 2018 Research Fund (1.180067.01) of the Ulsan National Institute of Science and Technology, and Basic Science Research Program through the National Research Foundation of Korea (NRF), which was funded by the Ministry of Education (NRF–2016R1D1A1B03936002) and National Honor Scientist Program (2010–0020414) of the NRF. The work at IMDEA was supported by the ‘Severo Ochoa’ programme for Centers of Excellence in Research and Development (MINECO; grant SEV–2016–0686), European Union structural funds and Comunidad de Madrid MAD2D-CM Program (S2013/MIT–3007), and Campus of International Excellence UAM + CSIC. Financial support at IMDEA and the University of Valencia was further provided by the Spanish Ministry for Science (MINECO–FEDER projects CTQ2014–58801 and CTQ2017–87054).

Author information

Affiliations

Authors

Contributions

M.S.K. conceived and supervised the project. K.S.K. and J.G. supported and assisted in supervising the project. V.K.S. and M.S.K. designed the experiments and analysed the data. V.K.S. and C.Y. performed most of the experiments. S.B., Y.Kim, Y.Kwon, D.K., J.L., T.A. and G.T. helped with the synthesis of OPCs and polymerization studies. P.C.N., R.W. and L.L. performed advanced photophysical measurements. B.M.-M. and J.G. carried out the quantum chemical calculations. L.S.P. and J.L. advised on the experiments. V.K.S., K.S.K., J.G. and M.S.K. prepared the manuscript, with contributions from all authors.

Corresponding authors

Correspondence to Kwang S. Kim or Johannes Gierschner or Min Sang Kwon.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Supplementary Information

Supplementary Methods, Supplementary Notes 1–7, Supplementary Figures 1–86, Supplementary Tables 1–10 and Supplementary References

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Singh, V.K., Yu, C., Badgujar, S. et al. Highly efficient organic photocatalysts discovered via a computer-aided-design strategy for visible-light-driven atom transfer radical polymerization. Nat Catal 1, 794–804 (2018). https://doi.org/10.1038/s41929-018-0156-8

Download citation

Further reading

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing