Non-π-Allyl Mechanism for the 1,4-cis-Butadiene Polymerization: Theoretical Study of Polymerization via Insertion of Butadiene into Al-C Bond with Cationic Gadolinium Metallocene

Chem Asian J. 2022 Dec 1;17(23):e202200899. doi: 10.1002/asia.202200899. Epub 2022 Oct 26.

Abstract

This paper reports a computational study on the specific 1,4-cis polymerization of butadiene catalyzed by the cationic gadolinium metallocene [(C5 Me5 )2 Gd][B(C6 F5 )4 ] combined with excess amount of Al(i Bu)3 . Because this reaction system has no initial Gd-alkyl bond, a mechanism with conventional coordinative chain transfer polymerization (CCTP) is not feasible. Density functional theory (DFT) analyses indicate a novel mechanism in which the cationic Gd plays a crucial role by assisting butadiene insertion into one of the Al-C bond of Al(i Bu)3 . The proposed butadiene polymerization mechanism can account for the specific 1,4-cis selectivity of this catalyst system.

Keywords: Alkylaluminum; Butadiene polymerization; DFT study; Lanthanides; Reaction mechanisms.

MeSH terms

  • Butadienes* / chemistry
  • Cations
  • Gadolinium*
  • Metallocenes
  • Models, Theoretical
  • Molecular Structure
  • Polymerization

Substances

  • 1,3-butadiene
  • Butadienes
  • Gadolinium
  • Metallocenes
  • metallocene
  • Cations