Effects of cyclopentadienyl fragment in ethylene,1-hexene,and styrene polymerizations catalyzed by half-titanocenes containing ketimide ligand of the type,Cp'TiCl_2(N=C~tBu_2)

摘要

Effects of substituents on cyclopentadienyl group for polymerization of ethylene.1-hexene and styrene with a series of(cyclo-pentadienyl)(ketimide)titanium(IV)complexes of type.Cp'TiCl_2(N=C~1Bu_2)[Cp'=Cp(1).~1BuC_5H_4(2).C_5Me_5(Cp' 3)].have been explored in the presence of methylaluminoxane(MAO)cocatalyst.Complexes 1-3 showed high catalytic activities for ethylene polymerization regardless of kind of cyclopentadienyl fragment,and the activity for 1-hexene polymerization increased in the order 12>3.These complexes also showed catalytic activities for syndiospecific styrene polymerization,however,the observed activities were much lower than those with Cp'TiCl_3.