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.

  • Article
  • Published:

Iron-catalysed synthesis and chemical recycling of telechelic 1,3-enchained oligocyclobutanes

Nature Chemistry volume 13, pages 156–162 (2021)Cite this article

Subjects

This article has been updated

Abstract

Closed-loop recycling offers the opportunity to mitigate plastic waste through reversible polymer construction and deconstruction. Although examples of chemical recycling of polymers are known, few have been applied to materials derived from abundant commodity olefinic monomers, which are the building blocks of ubiquitous plastic resins. Here we describe a [2+2] cycloaddition/oligomerization of 1,3-butadiene to yield a previously unrealized telechelic microstructure of (1,n′-divinyl)oligocyclobutane. This material is thermally stable, has stereoregular segments arising from chain-end control, and exhibits high crystallinity even at low molecular weight. Exposure of the oligocyclobutane to vacuum in the presence of the pyridine(diimine) iron precatalyst used to synthesize it resulted in deoligomerization to generate pristine butadiene, demonstrating a rare example of closed-loop chemical recycling of an oligomeric material derived from a commodity hydrocarbon feedstock.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Approaches to closed-loop recycling of polymers.
Fig. 2: A unique microstructure of polybutadiene obtained through iron-catalysed [2+2]-cycloaddition/oligomerization.
Fig. 3: Select thermal data for crystalline (1,n′-divinyl)polycyclobutane.
Fig. 4: Molecular dynamics simulated (1,17′-divinyl)polycyclobutane oligomer.
Fig. 5: Proposed catalytic cycle for the generation of oligocyclobutanes.
Fig. 6: Catalytic chemical recycling of cyclobutane structures.

Similar content being viewed by others

Data availability

All data necessary to support the conclusions of this paper are provided in the Supplementary Information, including optimized DFT coordinates and energetics, calculated free energies and MD equilibrated coordinates.

Change history

  • 22 February 2021

    In the version of this Article originally published, the Supplementary Information PDF was missing. This has now been corrected.

References

  1. Geyer, R., Jambeck, J. R. & Law, K. L. Production, use and fate of all plastics ever made. Sci. Adv. 3, e1700782 (2017).

    Article  PubMed  PubMed Central  Google Scholar 

  2. Rahimi, A. & García, J. M. Chemical recycling of waste plastics for new materials production. Nat. Rev. Chem. 1, 0046 (2017).

    Article  Google Scholar 

  3. Garcia, J. M. & Robertson, M. L. The future of plastics recycling. Science 358, 870–872 (2017).

    Article  CAS  PubMed  Google Scholar 

  4. Seeley, M. E., Song, B., Passie, R. & Hale, R. C. Microplastics affect sedimentary microbial communities and nitrogen cycling. Nat. Commun. 11, 2372 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  5. Sardon, H. & Dove, A. P. Plastics recycling with a difference. Science 360, 380–381 (2018).

    Article  CAS  PubMed  Google Scholar 

  6. Hopewell, J., Dvorak, R. & Kosior, E. Plastics recycling: challenges and opportunities. Philos. Trans. R. Soc. Lond. B Biol. Sci. 364, 2115–2126 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  7. Zhang, X., Fevre, M., Jones, G. O. & Waymouth, R. M. Catalysis as an enabling science for sustainable polymers. Chem. Rev. 118, 839–885 (2018).

    Article  CAS  PubMed  Google Scholar 

  8. Helms, B. A. & Russell, T. P. Reaction: polymer chemistries enabling cradle-to-cradle life cycles for plastics. Chem 1, 816–818 (2016).

    Article  CAS  Google Scholar 

  9. Hong, M. & Chen, E. Y. X. Chemically recyclable polymers: a circular economy approach to sustainability. Green Chem. 19, 3692–3706 (2017).

    Article  CAS  Google Scholar 

  10. Rowan, S. J., Cantrill, S. J., Cousins, G. R. L., Sanders, J. K. M. & Stoddart, J. F. Dynamic covalent chemistry. Angew. Chem. Int. Ed. 41, 898–952 (2002).

    Article  Google Scholar 

  11. Liu, T. et al. Eugenol-derived biobased epoxy: shape memory, repairing and recyclability. Macromolecules 50, 8588–8597 (2017).

    Article  CAS  Google Scholar 

  12. Ogden, W. A. & Guan, Z. Recyclable, strong and highly malleable thermosets based on boroxine networks. J. Am. Chem. Soc. 140, 6217–6220 (2018).

    Article  CAS  PubMed  Google Scholar 

  13. Zhu, J.-B., Watson, E. M., Tang, J. & Chen, E. Y.-X. A synthetic polymer system with repeatable chemical recyclability. Science 360, 398–403 (2018).

    Article  CAS  PubMed  Google Scholar 

  14. Christensen, P. R., Scheuermann, A. M., Loeffler, K. E. & Helms, B. A. Closed-loop recycling of plastics enabled by dynamic covalent diketoenamine bonds. Nat. Chem. 11, 442–448 (2019).

    Article  CAS  PubMed  Google Scholar 

  15. Lian, Z., Bhawal, B. N., Yu, P. & Morandi, B. Palladium-catalyzed carbon–sulfur or carbon–phosphorus bond metathesis by reversible arylation. Science 356, 1059–1063 (2017).

    Article  CAS  PubMed  Google Scholar 

  16. García, J. M. Catalyst design challenges for the future of plastics recycling. Chem 1, 813–815 (2016).

    Article  Google Scholar 

  17. Feldman, D. Polymer history. Des. Monomers Polym. 11, 1–15 (2008).

    Article  CAS  Google Scholar 

  18. Amghizar, I., Vandewalle, L. A., Van Geem, K. M. & Marin, G. B. New trends in olefin production. Eng. J. 3, 171–178 (2017).

    CAS  Google Scholar 

  19. Coates, G. W. & Getzler, Y. D. Y. L. Chemical recycling to monomer for an ideal, circular polymer economy. Nat. Rev. Mater. 5, 501–516 (2020).

    Article  CAS  Google Scholar 

  20. Pastine, S. J. Reaction: design with the end in mind. Chem 1, 818–819 (2016).

    Article  CAS  Google Scholar 

  21. Long, T. E. Reaction: benign by design demands innovation. Chem 2, 7–8 (2017).

    Article  CAS  Google Scholar 

  22. Russell, S. K., Lobkovsky, E. & Chirik, P. J. Iron-catalyzed intermolecular [2π+2π] cycloaddition. J. Am. Chem. Soc. 133, 8858–8861 (2011).

    Article  CAS  PubMed  Google Scholar 

  23. Hoyt, J. M., Schmidt, V. A., Tondreau, A. M. & Chirik, P. J. Iron-catalyzed intermolecular [2+2] cycloadditions of unactivated alkenes. Science 349, 960–963 (2015).

    Article  CAS  PubMed  Google Scholar 

  24. Hoyt, J. M., Sylvester, K. T., Semproni, S. P. & Chirik, P. J. Synthesis and electronic structure of bis(imino)pyridine iron metallacyclic intermediates in iron-catalyzed cyclization reactions. J. Am. Chem. Soc. 135, 4862–4877 (2013).

    Article  CAS  PubMed  Google Scholar 

  25. Schmidt, V. A., Hoyt, J. M., Margulieux, G. W. & Chirik, P. J. Cobalt-catalyzed [2π+2π] cycloadditions of alkenes: scope, mechanism and elucidation of electronic structure of catalytic intermediates. J. Am. Chem. Soc. 137, 7903–7914 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  26. Hall, H. K. Jr Synthesis and polymerisation of polycyclic compounds with strained C–C single bonds. Br. Polym. J. 4, 371–389 (1972).

    Article  CAS  Google Scholar 

  27. Hall, H. K. Jr & Ykman, P. Addition polymerization of cyclobutene and bicyclobutane monomers. J. Polym. Sci. Macromol. Rev. 11, 1–45 (1976).

    Article  CAS  Google Scholar 

  28. Wu, C. C. & Lenz, R. W. Thermal and autoxidation reactions of poly-3-methylenecyclobutene and poly-1-methyl-3-methylenecyclobutene. J. Polym. Sci. A Polym. Chem. 10, 3555–3567 (1972).

    Article  CAS  Google Scholar 

  29. Danopoulos, A. A., Wright, J. A. & Motherwell, W. B. Molecular N2 complexes of iron stabilised by N-heterocyclic ‘pincer’ dicarbene ligands. Chem. Commun. 784–786 (2005); https://doi.org/10.1039/b415562a

  30. Darmon, J. M. et al. Electronic structure determination of pyridine N-heterocyclic carbene iron dinitrogen complexes and neutral ligand derivatives. Organometallics 33, 5423–5433 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  31. Pagar, V. V. & RajanBabu, T. V. Tandem catalysis for asymmetric coupling of ethylene and enynes to functionalized cyclobutanes. Science 361, 68–72 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  32. Parsutkar, M. M., Pagar, V. V. & RajanBabu, T. V. Catalytic enantioselective synthesis of cyclobutenes from alkynes and alkenyl derivatives. J. Am. Chem. Soc. 141, 15367–15377 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  33. Bandrup, J., Immergut, E. & Grulke, E. Polymer Handbook 4th edn (Wiley-Blackwell, 2003).

  34. Kennedy, C. R., Zhong, H., Joannou, M. V. & Chirik, P. J. Pyridine(diimine) iron diene complexes relevant to catalytic [2+2]-cycloaddition reactions. Adv. Synth. Catal. 362, 404–416 (2020).

    Article  CAS  PubMed  Google Scholar 

  35. Kozuch, S. & Shaik, S. How to conceptualize catalytic cycles? The energetic span model. Acc. Chem. Res. 44, 101–110 (2011).

    Article  CAS  PubMed  Google Scholar 

  36. Pangborn, A. B., Giardello, M. A., Grubbs, R. H., Rosen, R. K. & Timmers, F. J. Safe and convenient procedure for solvent purification. Organometallics 15, 1518–1520 (1996).

    Article  CAS  Google Scholar 

  37. Wreford, S. S. & Whitney, J. F. Magnesium butadiene as a reagent for the preparation of transition-metal butadiene complexes: molecular structure of bis(η-butadiene)[1,2-bis(dimethylphosphino)ethane]hafnium. Inorg. Chem. 20, 3918–3924 (1981).

    Article  CAS  Google Scholar 

  38. Britovsek, G. J. P. et al. Iron and cobalt ethylene polymerization catalysts bearing 2,6-bis(imino)pyridyl ligands: synthesis, structures and polymerization studies. J. Am. Chem. Soc. 121, 8728–8740 (1999).

    Article  CAS  Google Scholar 

  39. Russell, S. K., Darmon, J. M., Lobkovsky, E. & Chirik, P. J. Synthesis of aryl-substituted bis(imino)pyridine iron dinitrogen complexes. Inorg. Chem. 49, 2782–2792 (2010).

    Article  CAS  PubMed  Google Scholar 

  40. Bart, S. C., Lobkovsky, E. & Chirik, P. J. Preparation and molecular and electronic structures of iron(0) dinitrogen and silane complexes and their application to catalytic hydrogenation and hydrosilation. J. Am. Chem. Soc. 126, 13794–13807 (2004).

    Article  CAS  PubMed  Google Scholar 

  41. Russell, S. K., Milsmann, C., Lobkovsky, E., Weyhermüller, T. & Chirik, P. J. Synthesis, electronic structure and catalytic activity of reduced bis(aldimino)pyridine iron compounds: experimental evidence for ligand participation. Inorg. Chem. 50, 3159–3169 (2011).

    Article  CAS  PubMed  Google Scholar 

  42. Bouwkamp, M. W., Bowman, A. C., Lobkovsky, E. & Chirik, P. J. Iron-catalyzed [2π+2π] cycloaddition of α,ω-dienes: the importance of redox-active supporting ligands. J. Am. Chem. Soc. 128, 13340–13341 (2006).

    Article  CAS  PubMed  Google Scholar 

  43. Rummelt, S. M. et al. Synthesis, structure and hydrogenolysis of pyridine dicarbene iron dialkyl complexes. Organometallics 38, 3159–3168 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  44. Cirera, J., Via-Nadal, M. & Ruiz, E. Benchmarking density functional methods for calculation of state energies of first row spin-crossover molecules. Inorg. Chem. 57, 14097–14105 (2018).

    Article  CAS  PubMed  Google Scholar 

  45. Jensen, K. P. Bioinorganic chemistry modeled with the TPSSh density functional. Inorg. Chem. 47, 10357–10365 (2008).

    Article  CAS  PubMed  Google Scholar 

  46. Srinivasan, S., Rappe, A. M. & Soroush, M. in Computational Quantum Chemistry: Insights into Polymerization Reactions Ch. 4 (Elsevier, 2019).

  47. Pápai, M. & Vanko, G. On predicting Mössbauer parameters of iron-containing molecules with density-functional theory. J. Chem. Theory Comput. 9, 5004–5020 (2013).

    Article  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

We are grateful to S. Klemenz and the Schoop laboratory for initial assistance with powder diffraction, as well as D. Gregory for assistance with TGA/GCMS and DSC. M.M.B. thanks K. Conover for assistance with high-temperature NMR experiments. M.M.B., C.R.K. and P.J.C. thank Firmenich for initial support of this work. M.M.B. and C.R.K. thank the NIH for Ruth L. Kirschstein National Research Service Awards (F32 GM134610 and GM126640). All authors thank ExxonMobil for support of this research.

Author information

Authors and Affiliations

  1. Department of Chemistry, Princeton University, Princeton, NJ, USA

    Megan Mohadjer Beromi, C. Rose Kennedy & Paul J. Chirik

  2. ExxonMobil Chemical Company, Baytown, TX, USA

    Jarod M. Younker, Alex E. Carpenter, Sarah J. Mattler & Joseph A. Throckmorton

Authors
  1. Megan Mohadjer Beromi
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. C. Rose Kennedy
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Jarod M. Younker
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Alex E. Carpenter
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Sarah J. Mattler
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Joseph A. Throckmorton
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Paul J. Chirik
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

C.R.K. and P.J.C. conceived the project. C.R.K. and M.M.B. performed experiments regarding the synthesis and partial characterization of oligomers. A.E.C. and S.J.M. conducted full NMR characterization and peak assignments. M.M.B., A.E.C. and J.A.T. performed experiments on the thermal stability and crystallinity of the oligomer. J.M.Y. conducted TST/DFT and molecular mechanics calculations. M.M.B. and A.E.C. performed the chemical recycling experiments.

Corresponding author

Correspondence to Paul J. Chirik.

Ethics declarations

Competing interests

C.R.K. and P.J.C. are inventors on patent application US 2019/0211142 A1 titled ‘Oligomeric and polymeric species comprising cyclobutane units’. J.M.Y., A.E.C., S.J.M. and J.A.T. are employees of ExxonMobil Chemical Company.

Additional information

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

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

Supplementary information

Supplementary Information

Supplementary Figs. 1–22, Tables 1–9 and references 1–34. Spectroscopic data for the oligocyclobutanes, chemical/stereochemical NMR shift assignments, DFT NMR simulations, WAXS data and MD simulations, TGA and DSC data, spectroscopic data for chemical recycling, gelation tests and DFT simulations of the reaction profile and associated discussion.

Supplementary Data 1

Optimized coordinates for the divinyloligocyclobutane dimer, trimer and butadiene using the B3LYP-D3 functional.

Supplementary Data 2

Optimized coordinates for the iron catalyst stationary points on the singlet energy surface using the B3LYP-D3 functional.

Supplementary Data 3

Optimized coordinates for the divinyloligocyclobutane dimer, trimer and butadiene using the M06L functional.

Supplementary Data 4

Optimized coordinates for the iron catalyst stationary points on the singlet energy surface using the M06L functional.

Supplementary Data 5

Optimized coordinates for the divinyloligocyclobutane dimer, trimer, and butadiene using the TPSSh functional.

Supplementary Data 6

Optimized coordinates for the iron catalyst stationary points using the broken symmetry (1,1) restrictions at the TPSSh level of theory.

Supplementary Data 7

Optimized coordinates for the iron catalyst stationary points using the broken symmetry (3,1) restrictions at the TPSSh level of theory.

Supplementary Data 8

Optimized coordinates for the iron catalyst stationary points on the singlet energy surface using the TPSSh functional.

Supplementary Data 9

Optimized coordinates for the iron catalyst stationary points on the triplet energy surface using the TPSSh functional.

Supplementary Data 10

Optimized coordinates for the iron catalyst stationary points on the quintet energy surface using the TPSSh functional.

Supplementary Data 11

Associated mae files for the calculated NMR shifts.

Supplementary Data 12

The resultant coordinates of the optimized geometries of the single strand oligomer.

Supplementary Data 13

The resultant coordinates of the optimized geometries of the supercell of the oligomer strands.

Supplementary Data 14

The raw data for the resultant coordinates of the optimized geometries of the single strand oligomer and supercell of the strands.

Supplementary Data 15

Combined spreadsheet comparing all functionals for all points in reaction profile.

Supplementary Data 16

Combined spreadsheet comparing all spin manifolds for all points in reaction profile.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Mohadjer Beromi, M., Kennedy, C.R., Younker, J.M. et al. Iron-catalysed synthesis and chemical recycling of telechelic 1,3-enchained oligocyclobutanes. Nat. Chem. 13, 156–162 (2021). https://doi.org/10.1038/s41557-020-00614-w

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41557-020-00614-w

This article is cited by

Search

Advanced 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