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- Title
Ethylene.
- Authors
Li, Aike; Xiao, Wei; Ma, Haiyan; Huang, Jiling
- Abstract
A series of group 4 metallocenes (RCp)[Cp-(bridge)-(2-C4H3S)]MCl2 [M = Ti ( C1, C2, C3, C4); M = Zr ( C5, C6, C7, C8)] bearing a pendant thiophene group on a cyclopentadienyl ring have been synthesized, characterized and tested as catalyst precursors for ethylene . The molecular structures of representative titanocenes C2 and C4 were confirmed by single-crystal X-ray diffraction and revealed that both complexes exist in an expected coordination environment for a monomeric bent metallocene. No coordination between the thiophene group and the titanium center could be observed in the solid state. Upon activation by methylaluminoxane (MAO), titanocenes C1, C2, C3, C4 showed moderate catalytic activities and produced high- or ultra-high-molecular-weight polyethylene ( Mv 70.5-227.1 × 104 g mol−1). Titanocene C3 is more active and long-lived, with a lifetime of nearly 9 h at 30 °C. At elevated temperatures of 80-110 °C, zirconocenes C5, C6, C7, C8 displayed high catalytic activities (up to 27.6 × 105 g PE (mol Zr)−1 h−1), giving high-molecular-weight polyethylene ( Mv 11.2-53.7 × 104 g mol−1). Even at 80 °C, a long lifetime of at least 2 h was observed for the C8/MAO catalyst system. Copyright © 2014 John Wiley & Sons, Ltd.
- Subjects
ETHYLENE; POLYMERIZATION research; THIENYL compounds; METALLOCENES; ZIRCONOCENES; THIOPHENES
- Publication
Applied Organometallic Chemistry, 2014, Vol 28, Issue 7, p495
- ISSN
0268-2605
- Publication type
Article
- DOI
10.1002/aoc.3153