Syntesis and characterization of bis(insenyl) zirconium aryloxide derivatives and their use in alpha-olefin polymerization.

A series of new bis(indenyl)zirconium diaryloxides of general formula Ind2Zr(OL)2 (L = C6H5, C6F5, 2,6-Me2C6H3, 2,4,6Me3C6H2, 4-tBUC6H4, were synthesized by a metathesis reaction of Ind2ZrC12 with the appropriate thallium aryloxide salt, Tl0L. The complexes were characterized by 1H and 13C NMR techniques. They were also examined as catalysts for ethene and 1-hexene polymerization with methylalumoxane as co-catalyst, and a trend of the polymerization activity as a funetion of aryloxide ligands was observed. An interpretation of this trend, considering both the electronic and steric effects of the substituents on the aryloxide rings, was proposed.