Synthesis, crystal structure and catalytic activity of a novel zirconium complex bearing an unsymmetrical aliphatic benzamidinato ligand

A novel non-symmetric aliphatic benzamidinato zirconium complex, [{CyNC(Ph)(NSiMe3)}2ZrCl2] (Cy = cyclohexyl) (1) has been readily prepared via the reaction of freshly prepared aliphatic lithium benzamidinate with zirconium tetrachloride. Complex 1 has been characterized by various spectroscopic techniques, elemental analysis, and single-crystal X-ray diffraction analysis. Complex 1 has a distorted pseudo-octahedral structure. Catalytic studies showed that the zirconium complex was active for ethylene polymerization with the activity of 6.66 × 104 g PE/mol Zr h. The influences of Al/Zr molar ratios, ethylene pressures and reaction temperature on the activities were investigated.