New half-sandwich zirconium(IV) complexes containing salicylaldimine ligands: Synthesis, characterizations and catalytic properties

Abstract

Two new half-sandwich zirconium(IV) complexes bearing salicylaldimine ligands of the type Cp*Zr[2-tBu-4-R-6-(CH=NiPr)C6H2O]Cl2[R=H(1), tBu(2)] were prepared by the reaction of Cp*ZrCl3 with the corresponding lithium of salicylaldimine ligands 2-tBu-4-R-6-(CH=NiPr)C6H2OLi[R=H(LiLa), tBu(LiLb)]. Complexes 1 and 2 were characterized by 1H NMR, 13C NMR spectroscopy and elemental analysis. When activated with AliBu3 and Ph3CB(C6F5)4, both complexes 1 and 2 exhibited reasonable catalytic activities for ethylene polymerization, producing polyethylenes with moderate molecular weight. Complexes 1 and 2 also exhibited reasonable catalytic activities for ethylene copolymerization with 1-hexene, producing poly(ethylene-co-1-hexene)s with moderate molecular weight and reasonable 1-hexene content.