Nucleophilically assisted and cationic ring-opening polymerization of tin-bridged [1]ferrocenophanes

Thomas Baumgartner, Frieder Jäkle, Ron Rulkens, Gernot Zech, Alan J. Lough, Ian Manners

Research output: Contribution to journalArticle

53 Citations (Scopus)

Abstract

To obtain mechanistic insight, detailed studies of the intriguing "spontaneous" ambient temperature ring-opening polymerization (ROP) of tin-bridged [1]ferrocenophanes Fe(η-C5H4)2SnR2 3a (R = t-Bu) and 3b (R = Mes) in solution have been performed. The investigations explored the influence of non-nucleophilic additives such as radicals and radical traps, neutral and anionic nucleophiles, Lewis acids, protic species, and other cationic electrophiles. Significantly, two novel methodologies and mechanisms for the ROP of strained [1]ferrocenophanes are proposed based on this study. First, as the addition of amine nucleophiles such as pyridine was found to strongly accelerate the polymerization rate in solution, a new nucleophilically assisted ROP methodology was proposed. This operates at ambient temperature in solution even in the presence of chlorosilanes but, unlike the anionic polymerization of ferrocenophanes, does not involve cyclopentadienyl anions. Second, the addition of small quantities of the electrophilic species H+ and Bu3Sn+ was found to lead to a cationic ROP process. These studies suggest that the "spontaneous" ROP of tin-bridged [1]ferrocenophanes may be a consequence of the presence of spurious, trace quantities of Lewis basic or acidic impurities. The new ROP mechanisms reported are likely to be of general significance for the ROP of other metallocenophanes (e.g., for thermal ROP in the melt) and for other metallacycles containing group 14 elements.

Original languageEnglish (US)
Pages (from-to)10062-10070
Number of pages9
JournalJournal of the American Chemical Society
Volume124
Issue number34
DOIs
StatePublished - Aug 28 2002

Fingerprint

Cationic polymerization
Tin
Ring opening polymerization
Polymerization
Nucleophiles
Lewis Acids
Anionic polymerization
Temperature
Pyridine
Amines
Anions
Negative ions
Impurities
Hot Temperature
Acids

All Science Journal Classification (ASJC) codes

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

Cite this

Baumgartner, Thomas ; Jäkle, Frieder ; Rulkens, Ron ; Zech, Gernot ; Lough, Alan J. ; Manners, Ian. / Nucleophilically assisted and cationic ring-opening polymerization of tin-bridged [1]ferrocenophanes. In: Journal of the American Chemical Society. 2002 ; Vol. 124, No. 34. pp. 10062-10070.
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Nucleophilically assisted and cationic ring-opening polymerization of tin-bridged [1]ferrocenophanes. / Baumgartner, Thomas; Jäkle, Frieder; Rulkens, Ron; Zech, Gernot; Lough, Alan J.; Manners, Ian.

In: Journal of the American Chemical Society, Vol. 124, No. 34, 28.08.2002, p. 10062-10070.

Research output: Contribution to journalArticle

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T1 - Nucleophilically assisted and cationic ring-opening polymerization of tin-bridged [1]ferrocenophanes

AU - Baumgartner, Thomas

AU - Jäkle, Frieder

AU - Rulkens, Ron

AU - Zech, Gernot

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AU - Manners, Ian

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