Synthesis and physico-chemical characterization of [Hf(NEt2)2Cl2(DME)] and its use as catalyst for ethylene polymerization

The new bis-diethylamide bis-isopropoxy hafnium complex [Hf(NEt2)2(OCH(CH3)2)2] as well as the intermediate solid-state complex {[Hf(NEt2)2Cl2.DME] (DME=1,2-dimethoxyethane)} have been synthetized, isolated and characterized by NMR spectroscopy. The dichloride complex was also characterized by X-ray diffraction showing the metal to be hexa-coordinated with a distorted octahedral geometry. Catalytic tests for the polymerization of ethylene have been carried out using this intermediate with [(NHMe2Ph)B(C6F5)4] as cocatalyst.