Non-cyclopentadienyl zirconium complexes as catalysts for 1-hexene polymerization

The new β-diketonate complexes (hfac)2ZrCl2, (hfac)3ZrCl, hfac = hexafluoroacetylacetonate, and (thd)2ZrCl2, thd = 2,2,6,6-tetramethyl-3,5-heptanedionate, have been prepared in good yield by reacting the corresponding β-diketonate thallium complexes with ZrCl4 in stoichiometric amounts and they have been characterized by elemental analyses and NMR spectra. These complexes and the β-diketonate complexes (acac)2ZrCl2, (acac)3ZrCl and (thd)3ZrCl have been tested as catalysts in the polymerization of 1-hexene in the presence of N,N′-(dimethylanilinium)-tetrakis(pentafluorophenylborate) or ethyltrichloroacetate as co-catalysts at room temperature using ethyl aluminum sesquichloride as scavenger.