Impact of Labile Ligands on Catalyst Initiation and Chain Propagation in Ni-Catalyzed Ethylene/Acrylate Copolymerization

Creators: Xiong, Shuoyan; Ghana, Priyabrata; Bailey, Brad C.; Spinney, Heather A.; Henderson, Briana S.; Espinosa, Matthew R.; Agapie, Theodor¹

1. California Institute of Technology

Abstract

Polar polyolefin synthesis by coordination polymerization is of high interest, but the catalysts’ low activity limits industrial implementation. Herein, we demonstrate how the nature of the labile ligand, L, impacts the performance of neutral nickel catalysts supported by bidentate phosphine-phenoxide and phosphine-enolate ligands in ethylene/acrylate copolymerization. By tuning L, the copolymerization activity reaches ∼24000 kg/(mol h). In situ studies indicate that a weaker L leads to faster chain propagation and more efficient catalyst initiation. Overall, this work highlights the potential of a strategy to improve catalyst activity in polar polyolefin synthesis complementary to design optimization for the bidentate ligand.

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Acknowledgement

We are grateful to Dow (T.A.) for funding. We thank Alex J. Nett and Todd D. Senecal for insightful discussions. We thank Manar M. Shoshani and Linh N.V. Le for assistance with X-ray crystallography, and David VanderVelde for assistance with NMR spectroscopy. We thank Heidi Clements, Hannah Bailey, and Katie Muron for assistance in collecting polymer characterization data (GPC, DSC, FT-IR). Support has been provided for the X-ray diffraction and NMR instrumentation via the Dow Next Generation Educator Fund.

Contributions

The manuscript was written through contributions of all authors.

Data Availability

Combined crystallographic information file (CIF)
Experimental section, synthetic procedures, characterization data, ligand exchange studies, and polymerization studies (PDF)

Accession Codes

CCDC 2240825–2240827 contains the supplementary crystallographic data for this paper.

Conflict of Interest

The authors declare no competing financial interest.

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