Synthesis, structures, and catalytic properties for ethylene polymerization of bridged [η5,η1-C5H4CHPhArO]TiCl2 complexes
摘要:
A number of bridged half-sandwich titanium complexes [eta(5):eta(1)-2-C5H4CHPh-4-R-1-6-(RC6H2O)-C-2]TiCl2 [R-1= H (5), Me (6), Bu-t (7,8); R-2= H (6,7), Bu-t (5,8)] were synthesized from the reaction of their corresponding trimethylsilyl substituted ligand precursors 2-Me3SiC5H4CHPh-4-R-1-6-(RC6H2OSiMe3)-C-2 [R-1= H (1), Me (2), Bu-t (3,4); R-2= H (2,3), Bu-t (1,4)] with TiCl4 in hexane. All new complexes were characterized by H-1 and C-13 NMR spectroscopy. Molecular structures of complexes 5 and 8 were determined by single crystal X-ray diffraction analysis. Upon activation with (AlBu3)-Bu-i/Ph3CB (C6F5)(4), complexes 5-8 exhibit reasonable catalytic activity for ethylene polymerization and copolymerization with 1-hexene, producing polyethylene and poly(ethylene-co-1-hexene) with moderate molecular weights. (C) 2008 Elsevier B.V. All rights reserved.