Synthesis and application of molybdenum (III) complexes bearing weakly coordinating anions as catalysts of isobutylene polymerization |
| |
| Authors: | Bernd E. Diebl Yang Li Mirza Cokoja Fritz E. Kühn Narayanan Radhakrishnan Stefan Zschoche Hartmut Komber Hui Yee Yeong Brigitte Voit Oskar Nuyken Phillip Hanefeld Hans‐Michael Walter |
| |
| Affiliation: | 1. Technische Universit?t München, Catalysis Research Center, Molecular Catalysis, Lichtenbergstrasse 4, D‐85747 Garching, Germany;2. Technische Universit?t München, Catalysis Research Center, Chair of Inorganic Chemistry, Lichtenbergstrasse 4, D‐85747 Garching, Germany;3. Leibniz‐Institut für Polymerforschung Dresden e.V., Hohe Strasse 6, D‐01069 Dresden, Germany;4. Technische Universit?t München, Chair of Macromolecular Chemistry, Lichtenbergstrasse 4, D‐85747 Garching, Germany;5. BASF SE, GKS/M ‐ B001, D‐67056 Ludwigshafen, Germany |
| |
| Abstract: | Acetonitrile ligated molybdenum (III) complexes of the structure [MoCl(NCCH3)5]2+ bearing different weakly coordinating anions [B(C6F5)4]? (WCA a), [B{C6H3(m‐CF3)2}4]? (WCA b) and [(C6F5)3B‐C3H3N2‐B(C6F5)3]? (WCA c) were applied as homogeneous catalysts of the polymerization of isobutylene. High monomer conversions were obtained in short reaction times (<30 min). The molecular weight of the resulting polyisobutylene is nearly independent of parameters such as temperature, solvent, monomer concentration, but is strongly influenced by the type of WCA and by chain transfer reactions which were observed in these systems. Highly reactive low molecular weight polyisobutylenes (Mn < 2000 g/mol) were obtained with a high content of exo double bond end groups as shown by 1H NMR analysis. Furthermore, experiments were performed to reduce the isomerization of these exo end groups into other internal double bonds by varying the polymerization parameters. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3775–3786, 2010 |
| |
| Keywords: | catalysis polymerization polyolefins transition metal chemistry weakly coordinating anions |
|
|
