Copolymerization behavior of titanium imidazolin‐2‐iminato complexes |
| |
| Authors: | Simon H Stelzig Matthias Tamm Robert M Waymouth |
| |
| Institution: | 1. Institut für Anorganische Chemie, Technische Universit?t München, Lichtenbergstr. 4, D‐85747 Garching b. München, Germany;2. Institut für Anorganische und Analytische Chemie, Technische Universit?t Braunschweig, Hagenring 30, 38106 Braunschweig;3. Department of Chemistry, Stanford University, Stanford, California 94305‐5080 |
| |
| Abstract: | Monocyclopentadienyl titanium imidazolin‐2‐iminato complexes Cp′Ti(L)X2] 1a (Cp′ = cyclopentadienyl, L = 1,3‐di‐tert‐butylimidazolin‐2‐imide, X = Cl), 1b (X = CH3); 2 (Cp′ = cyclopentadienyl, L = 1,3‐diisopropylimidazolin‐2‐imide, X = Cl); 3 (Cp′ = tert‐butylcyclopentadienyl, L = 1,3‐di‐tert‐butylimidazolin‐2‐imide, X = Cl), upon activation with methylaluminoxane (MAO) were active for the polymerization of ethylene and propylene and the copolymerization of ethylene and 1‐hexene. Catalysts derived from imidazolin‐2‐iminato tropidinyl titanium complex 4 = (Trop)Ti(L)Cl2] (Trop = tropidinyl, L = 1,3‐di‐tert‐butylimidazolin‐2‐imide) were much less active. Narrow polydispersities were observed for ethylene and propylene polymerization, but the copolymerization of ethylene/hexene led to bimodal molecular weight distributions. The productivity of catalysts derived from the dialkyl complex 1b activated with Ph3C]B(C6F5)4] or B(C6F5)3 were less active for ethylene/hexene copolymerization but yielded ethylene/hexene copolymers of narrower molecular weight distributions than those derived from 1a/MAO. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6064–6070, 2008 |
| |
| Keywords: | catalysis copolymerization imidazolin‐2‐iminato ligands metallocene catalysts polyethylene (PE) tropidinyl ligand |
|
|
