RESUMO
A series of bis(phenoxy-imine) (FI) titanium(IV) and zirconium(IV) complexes have been synthesized. The effect of the nature of the activator (MAO, combinations EtnAlCl3-n + Bu2Mg and iBu3Al + [Ph3C]+[B(C6F5)4]-) on the catalytic activity and properties of the resulting polymers was studied. It was found that Ti-Fi complexes, despite the nature of the outgoing ligands (Cl or iPrO) in the presence of Al/Mg activators, effectively catalyze the polymerization of ethylene (with the formation of UHMWPE); copolymerization of ethylene with 1-octene (with the formation of ultra-high molecular weight copolymers); and the ternary copolymerization of ethylene, propylene and 5-vinyl-2-norbornene (with the formation of polyolefin elastomers). It has been shown that Zr-FI complexes are not activated by these Al/Mg compositions. The resulting UHMWPE can be processed by a solventless method into high-strength and high-modulus oriented films; however, their mechanical characteristics do not exceed those obtained using MAO.
RESUMO
The crystal structure of the title zwitterionic zirconocene complex containing a furan-one unit, [AlZr(C10H15)2(C4H9)3(C9H18O2Si2)], is reported. On reacting a zircona-furan-one with two equivalents of HAl(i-Bu)2, disproportionation of the Lewis acid results in the formation of a triiso-butyl-aluminium fragment, Al(i-Bu)3, which coordinates to the exocyclic carbonyl O atom of the zircona-furan-one ring. Single-crystal X-ray diffraction reveals that the zircona-furan-one ring remains intact with coordination of the aluminium to the exocyclic O atom. One of the i-butyl groups is disordered over two sets of sites, with an occupancy ratio of 0.731â (3):0.269â (3).