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

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. Access through your institution Buy or subscribe This is a preview of subscription content, access via your institution

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FAQs * Contact customer support SIMILAR CONTENT BEING VIEWED BY OTHERS UPCYCLING POLYETHYLENE INTO CLOSED-LOOP RECYCLABLE POLYMERS THROUGH TITANOSILICATE CATALYZED C-H OXIDATION AND

IN-CHAIN HETEROATOM INSERTION Article Open access 24 October 2024 TAILORED SYNTHESIS OF CIRCULAR POLYOLEFINS Article 11 March 2025 BIFUNCTIONAL AND RECYCLABLE POLYESTERS BY CHEMOSELECTIVE

RING-OPENING POLYMERIZATION OF A Δ-LACTONE DERIVED FROM CO2 AND BUTADIENE Article Open access 08 October 2024 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

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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 * Department of Chemistry, Princeton

University, Princeton, NJ, USA Megan Mohadjer Beromi, C. Rose Kennedy & Paul J. Chirik * ExxonMobil Chemical Company, Baytown, TX, USA Jarod M. Younker, Alex E. Carpenter, Sarah J.

Mattler & Joseph A. Throckmorton Authors * Megan Mohadjer Beromi View author publications You can also search for this author inPubMed Google Scholar * C. Rose Kennedy View author

publications You can also search for this author inPubMed Google Scholar * Jarod M. Younker View author publications You can also search for this author inPubMed Google Scholar * Alex E.

Carpenter View author publications You can also search for this author inPubMed Google Scholar * Sarah J. Mattler View author publications You can also search for this author inPubMed Google

Scholar * Joseph A. Throckmorton View author publications You can also search for this author inPubMed Google Scholar * Paul J. Chirik View author publications You can also search for this

author inPubMed 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 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: 25 February 2020 * Accepted: 28 October 2020 * Published: 25 January 2021 * Issue Date: February 2021 * DOI: https://doi.org/10.1038/s41557-020-00614-w SHARE THIS ARTICLE Anyone

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