Novel zirconium complexes containing a bidentate phenoxybenzotriazole ligand

Abstract

Treatment of CpZrCl(3) with 1 equiv of 2-(2H-benzoic[d][1,2,3]triazol-2-yl)-4,6-di-tert-pentylphenol (LigH) in THF or toluene affords the monomeric complex C(31)H(41)Cl(2)N(3)O(2)Zr (1) or the dimeric complex C(54)H(66)Cl(4)N(6)O(2)Zr(2) (2), respectively. THF can transform the dimeric 2 into monomeric 1 within a few minutes at room temperature. The reaction between LigH and 2 equiv of CpZrCl(3) gave the novel dinuclear complex C(32)H(38)Cl(5)N(3)OZr(2) (3), linked by three bridging chlorides. The monomeric complex C(44)H(56)Cl(2)N(6)O(2)Zr (4), containing two Lig and two Cl ligands, could be obtained by the reaction between 2 equiv of LigH and Zr(NMe(2))(4) in toluene and subsequent addition of Me(3)SiCl. The molecular structures of the complexes were determined by the single crystal X-ray crystallographic method. In the presence of methylalumoxane (MAO) as a cocatalyst, the four complexes synthesized were highly active for the polymerization of ethylene. (C) 2010 Elsevier Ltd. All rights reserved.