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. 2025 Oct 16;16(1):9181.
doi: 10.1038/s41467-025-64209-0.

1,1-polymerization of acetylene

Tairan Cheng  1 , Jiayao Qiu  1 , Zedong Yang  1 , Siju Li  1 , Huanfeng Jiang  1 , Shifa Zhu  2   3   4
Affiliations

1,1-polymerization of acetylene

Tairan Cheng et al. Nat Commun. .

Abstract

The polymerization of alkynes has long been a cornerstone of materials science, yielding a plethora of π-bond-rich materials and underpinning the 2000 Nobel Prize in Chemistry. While 1,2-polymerization of alkynes via 1,2-addition has been extensively studied, the 1,1-polymerization of carbon carbon triple bonds remains a formidable challenge due to the necessity of an alkyne rearrangement step during polymerization. Here we report the 1,1-polymerization of acetylene gas through a Cd-catalyzed iterative 1,1-carboboration process, achieving a broad terminal functionalization scope and functional group compatibility. This product, 1,1-polyacetylene (1,1-PA), also named as dendralene, exhibits unique physical and chemical properties, including an explosive tendency, distinguishing it from the 1,2-polyacetylene (1,2-PA) counterparts.

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Conflict of interest statement

Competing interests: The authors declare no competing interests.

Figures

Fig. 1
Fig. 1. Background for the synthesis of 1,1-PA.
a Polyacetylene by 1,2-polymerization– and 1,1-polymerization. b Synthesis of dendralenes by coupling reaction–. c Synthesis of dendralenes by SNV reaction. d Synthesis of dendralenes from strained [3]cumulenes. e Polyhomologation of methylidene sulfur ylide. f Single step 1,1-carboboration of acetylene and terminal alkynes–, NHC N-heterocyclic carbene, BBN 9-borabicyclo[3.3.1]nonane. g Iterative 1,1-carboboration of acetylene.
Fig. 2
Fig. 2. Characterization of short-chain 1,1-PA.
a 1H NMR (CDCl3) spectrum of dodecyl 1,1-PA. b 13C NMR (CDCl3) spectrum of dodecyl 1,1-PA. c HRMS of dodecyl 1,1-PA.
Fig. 3
Fig. 3
Synthesis of short-chain 1,1-PAs. †Ph-BBN was synthesized from PhMgBr and Cl-BBN and was isolated before use. ‡Hydroboration conditions: non-standard stoichiometry/temperature/handling. See SI. Isolated yields corrected for residual impurities/solvent.
Fig. 4
Fig. 4
Application of short-chain 1,1-PAs. Isolated yields corrected for residual impurities/solvent.
Fig. 5
Fig. 5. Long-chain 1,1-PAs.
a Two photos of 5a before and after explosion. b Solid state 13C NMR of 5a. c Substrate scope: 5 mmol scale for 5a and 0.5 mmol scale for others. DP determined by end group elemental analysis. Isolated yields.
Fig. 6
Fig. 6. Explosion tests and SEM characterization of 1,1-PA.
a Explosion of 100 mg 5a under air ignited by fire. b Explosion of 0.5 g 5a under nitrogen ignited by 120 °C heating. c SEM image of a particle of 5a. d SEM image of a thin layer on one particle of 5a.
Fig. 7
Fig. 7
Computed preferential conformation of 1,1-PA. DFT calculations were performed at the B3LYP/6-31 G level of theory.
See this image and copyright information in PMC

References

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