Diebl, B. E.; Li, Y.; Cokoja, M.; Kuhn, F. E.; Radhakrishnan, N.; Zschoche, S.; Komber, H.; Yeong, H. Y.; Voit, B.; Nuyken, O.; Hanefeld, P.; Walter, H. M.
Synthesis and Application of Molybdenum (III) Complexes Bearing Weakly Coordinating Anions as Catalysts of Isobutylene Polymerization
Acetonitrile ligated molybdenum (III) complexes of the structure [MoCl(NCCH(3))(5)](2+) bearing different weakly coordinating anions [B(C(6)F(5))(4)](-) (WCA a), [BC(6)H(3)(m-CF(3))(2)(4)](-) (WCA b) and [(C(6)F(5))(3)B-C(3)H(3)N(2)-B(C(6)F(5))(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 (M(n) < 2000 g/mol) were obtained with a high content of exo double bond end groups as shown by (1)H 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. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3775-3786, 2010
ISI Document Delivery No.: 644LC Times Cited: 6 Cited Reference Count: 54 Diebl, Bernd E. Li, Yang Cokoja, Mirza Kuehn, Fritz E. Radhakrishnan, Narayanan Zschoche, Stefan Komber, Hartmut Yeong, Hui Yee Voit, Brigitte Nuyken, Oskar Hanefeld, Phillip Walter, Hans-Michael Cokoja, Mirza/B-6906-2009; Voit, Brigitte/D-4755-2009; Kuhn, Fritz/A-3113-2010 German Research Foundation (DFG); International Graduate School of Science and Engineering (IGSSE); Fonds der Chemischen Industrie; Universitat Bayern e.V.; BASF SE, Ludwigshafen This work was supported by the German Research Foundation (DFG), the International Graduate School of Science and Engineering (IGSSE), the Fonds der Chemischen Industrie, the Universitat Bayern e.V. and BASF SE, Ludwigshafen. Janos Mink (Hungarian Academy of Sciences) is also acknowledged for helpful discussions. 6 John wiley & sons inc Hoboken
Journal of Polymer Science Part a-Polymer Chemistry