Half-titanocene complexes bearing bulky dibenzhydryl-substituted aryloxide ligand: Syntheses, characterization, and ethylene (Co-) polymerization behaviors
writer:Bo Dong a, b, Hexin Zhang b, Hua Li c, Heng Liu b, Jun Guo b, Chunyu Zhang b, Xu Zhang a, Yanming Hu
keywords:Bulky aryloxide Half-titanocene complexes Ethylene polymerization Copolymerization
source:期刊
specific source:Polymer 100 (2016) 188e193
Issue time:2016年
Three half-titanocene complexes 2a-3a bearing dibenzhydryl-substituted aryloxide ligands CpTiCl2(O-2,6-Ph2CHeC6H2-4-Me), 2a; CpTiCl2 (O-2,6-Ph2CHeC6H2-4-OMe), 2b; Cp*TiCl2(O-2,6-Ph2CHeC6H2-4-Me), 3a were synthesized. All the complexes were characterized by NMR spectroscopy and elemental analysis. The molecular structures of complex 2a and 2b were further determined by single crystal X-ray diffraction, both of them adopt a three-legged distorted tetrahedral geometry in which the aryl substituents are orthogonally to the aryloxide group. Activated by methylaluminoxane (MAO), these complexes showed high activities (up to 2100 kg mol1 (Ti) h1) for ethylene polymerization. The resultant polyethylenes had high molecular weight and narrow molecular weight distributions. Furthermore, for the ethylene/1-hexene copolymerization, these complexes exhibited moderate activites and moderate to high 1-hexene incorporation ability. The sequence distributions of poly (ethylene-co-1-hexene)s are
greatly influenced by the substituent on the cyclopentadineyl group of titanium complexes.