| 초록 |
Cp*TiCl2(NR1R2)(Cp* = C5Me5; R1= phenyl, 2-biphenyl, 2-terphenyl; R2= phenyl, 2-biphenyl, 1-naphtyl, 2-naphyl) have been prepared by the reaction of Cp*TiCl3 with the corresponding lithium amide in toluene. These complexes exhibited high catalytic activities for ethylene polymerization in the presence of Ph3CB(C6F5)4/m-MAO at high temperature; especially Cp*TiCl2[NR1R2(R1=2-biphenyl, R2=phenyl) exhibited hightest catalytic activity (6.91 kg of PE/(mmol of Ti), ethylene 30 kg/cm2 at 140 °C and the resultant polymer possessed high molecular weight(Mw=390000) and molecular weight distribution(Mw/Mn= 3.2). Unusually slow kinetics of these catalytic system represented the unique role of aryl substituents on the ancillary ligand of piano-stool titanium(IV) complexes. |
