Group 4 metals complexes bearing anilidomethylpyridine ligands have been synthesized and characterized by NMR spectroscopy, elemental anal., and single-crystal X-ray diffraction anal. All complexes, after activation by using AliBu2H and methylalumoxane (MAO) were tested in 1,3-butadiene and α-olefins polymn. The zirconium complexes showed higher activity with respect to the titanium homologous. Polymn. of ethylene resulted, in all cases in the prodn. of high mol. wt. linear polyethylene. Propylene polymn. tests provided substantially atactic polypropylene. 1,3-Butadiene polymns. produced cis-1,4 polybutadiene, and in the case of zirconium complexes polymers with a content of cis-1,4 units higher a 99.9% were provided. Activity and stereoselectivity of the catalysts were related to the steric features of the complexes.
New (Anilidomethyl)pyridine Titanium(IV) and Zirconium(IV) Catalyst Precursors for the Highly Chemo- and Stereoselective cis-1,4-Polymerization of 1,3-Butadiene
PRAGLIOLA, Stefania;TEDESCO, Consiglia;PELLECCHIA, Claudio
2011-01-01
Abstract
Group 4 metals complexes bearing anilidomethylpyridine ligands have been synthesized and characterized by NMR spectroscopy, elemental anal., and single-crystal X-ray diffraction anal. All complexes, after activation by using AliBu2H and methylalumoxane (MAO) were tested in 1,3-butadiene and α-olefins polymn. The zirconium complexes showed higher activity with respect to the titanium homologous. Polymn. of ethylene resulted, in all cases in the prodn. of high mol. wt. linear polyethylene. Propylene polymn. tests provided substantially atactic polypropylene. 1,3-Butadiene polymns. produced cis-1,4 polybutadiene, and in the case of zirconium complexes polymers with a content of cis-1,4 units higher a 99.9% were provided. Activity and stereoselectivity of the catalysts were related to the steric features of the complexes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
