SYNTHESIS, CHARACTERIZATION AND REACTIVITY OF AMIDO TITANIUM AND ZIRCONIUM COMPLEXES

The polymerization of ethylene and propylene was studied by using a se ries of mono- and spirocyclic coordinatively unsaturated early transit ion metal amides as pre-catalysts. Amido complexes were prepared eithe r by metathesis reaction of Cp(2)ZrCl(2) and the dilithium salt of the bisamido ligand (Me(3)SiN-(CN2)(2)-NSiMe(3))(2-), by transamination r eaction of Zr(NMe(2))(4) with two equivalents of the diamine ligand (M e(3)SiNH-(CH2)(2)-NHSiMe(3)) and by metathesis reaction of ZrCl4 . 2TH F or TiCl4 with equimolar amounts of the dilithium salt (Me(3)SiN-(CH2 )(2)-NSiMe(3))(2-). The complexes obtained were characterized by stand ard spectroscopic techniques. 'Cationic' polymerization catalysts were generated from the early transition-metal amides with methylalumoxane . Polymerization activity is dependent on catalyst and co-catalyst con centrations.