Olefin Polymerization and Copolymerization by Complexes Bearing [ONNO]-Type Salan Ligands: Effect of Ligand Structure and Metal Type (Titanium, Zirconium, and Vanadium)

摘要

A series of novel titanium(IV) complexes bearing tetradentate [ONNO] salan type ligands: [Ti{2,2'-(OC_6H_3-5-t- Bu)_2-NHRNH}Cl_2] (Lig1TiCl_2: R_5C_2H_4; Lig_2TiCl_2: R_5C_4H_8; Lig_3- TiCl_2: R_5C_6H_(12)) and [Ti{2,2'-(OC_6H_2-3,5-di-t-Bu)_2-NHC_6H_(12)NH} Cl_2] (Lig_4TiCl_2) were synthesized and used in the (co)polymerization of olefins. Vanadium and zirconium complexes: [M{2,2'- (OC_6H_3-3,5-di-t-Bu)_2-NHC_6H_(12)NH}Cl_2] (Lig_4 VCl_2: M_5V; Lig_4ZrCl_2: M_5Zr) were also synthesized for comparative investigations. All the complexes turned out active in 1-octene polymerization after activation by MAO and/or Al(i-Bu)_3/[Ph_3C][B(C_6F_5)_4]. The catalytic performance of titanium complexes was strictly dependent on their structures and it improves for the increasing length of the aliphatic linkage between nitrogen atoms (Lig~1TiCl_2 Lig~2TiCl_2