Addition Polymers of Strained Cyclic Olefins – Transition Metal Catalysed Polymerisations of the Cyclobutene Derivative Bicyclo[3.2.0]hept-6-ene
✍ Scribed by Katherine Curran; Wilhelm Risse; Laura Boggioni; Incoronata Tritto
- Publisher
- John Wiley and Sons
- Year
- 2008
- Tongue
- English
- Weight
- 222 KB
- Volume
- 209
- Category
- Article
- ISSN
- 1022-1352
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Bicyclo[3.2.0]hept‐6‐ene was converted into the corresponding addition polymer poly(6,7‐bicyclo[3.2.0]heptylene) with the aid of early and late transition metal based olefin polymerisation catalysts. Moderate to very good yields (42–99%) of polymer were obtained with [Pd(NCEt)~4~][BF~4~]~2~, [(η^3^‐allyl)Pd(solv)~2~][SbF~6~], [(2,9‐dimethyl‐1,10‐phenanthroline)Pd(CH~3~)(NC(CH~2~)~6~CH~3~)][SbF~6~], and Cp~2~ZrCl~2~/MAO, using monomer to transition metal ratios between 50/1 and 250/1. Reaction occurs at the olefin π‐bond, and the four‐membered ring of the monomer is retained during polymerisation which differs from ring‐opening olefin metathesis polymerisation in which the four‐membered ring is opened. The nearly exclusively saturated structure of the polymer was confirmed by ^1^H and ^13^C NMR spectroscopy. It is proposed that the polymers consist of repeating units that are predominantly cis‐exo‐enchained. GPC analysis of the soluble polymers prepared with [Pd(NCEt)~4~][BF~4~]~2~ showed that the molecular mass values $\overline M _{\rm n}$(GPC) were in the range of 3 700 to 22 600.
magnified image