Ligand effects in the non-alternating CO-ethylene copolymerization by palladium(II) catalysis

Lorenzo Bettucci, Claudio Bianchini, Carmen Claver, Eduardo J. Garcia-Suarez, Aurora Ruiz, Andrea Meli, Werner Oberhauser

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

In this paper we report on a comparative study of the non-alternating CO-C2H4 copolymerization catalyzed by neutral Pd-II complexes with the phosphine-sulfonate ligands bis(o-methoxyphenyl)-phosphinophenylenesulfonate and bis(o-methoxyphenyl) phosphino-ethylenesulfonate. The former ligand, featuring a lower skeletal. exibility, has been found to form more active catalysts as well as produce polyketones with higher molecular weight and higher extra-ethylene incorporation. Operando high-pressure NMR studies have allowed us to intercept, for the first time, Pd-II( phosphine-sulfonate) beta-chelates in the non-alternating copolymerization cycle, while model organometallic reactions have contributed to demonstrate that Pd-II (phosphine-sulfonate) fragments do not form stable carbonyl complexes. The opening of the beta-chelates has been found to be a viable process by either comonomer, which contrasts with the behaviour of Pd-II (chelating diphosphine) catalysts for the perfectly alternating copolymerization.
Original languageEnglish
JournalDalton Transactions
Issue number47
Pages (from-to)5590-5602
Number of pages13
ISSN1477-9226
DOIs
Publication statusPublished - 2007
Externally publishedYes

Keywords

  • Copolymerization
  • Ethylene
  • High pressure effects
  • Ligands
  • Molecular weight
  • Organometallics
  • Palladium compounds
  • Catalysis
  • Active catalysts
  • Copolymerization cycle
  • Organometallic reactions
  • Stable carbonyl complexes
  • L
  • T
  • X
  • CHEMISTRY,
  • LOW-MOLECULAR-WEIGHT
  • CARBON-MONOXIDE
  • CO/ETHENE COPOLYMERIZATION
  • OLEFIN POLYMERIZATION
  • COMPLEXES RELEVANT
  • P,O CHELATE
  • ETHENE
  • METHANOLYSIS
  • DIPHOSPHINE
  • HYDRIDE

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