Synthesis of zirconocene complexes and their use in slurry-phase polymerisation of ethylene

A new family of zirconocene complexes of the type ((3-R)Ind(#))(2)ZrX(2) (where Ind(#) = C(6)Me(5)H and R = Me, Et and Ph) have been synthesised and fully characterised. Six new crystal structures have been reported (meso-((3-Et)Ind(#))(2)ZrBr(2), rac-((3-Et)Ind(#))(2)ZrCl(2), rac-((3-Et)Ind(#))(2)Zr(CH(2)Ph)(2), meso-((3-Et)Ind(#))(2)Zr(CH(2)Ph)(2), meso-((3-Me)Ind(#))(2)ZrBr(2) and meso-((3-Me)Ind(#))(2)Zr(CH(2)Ph)(2)). The complexes were studied for slurry-phase ethylene polymerisation when immobilised on solid polymethylaluminoxane (sMAO). Variation in the initiation group was found to have greater influence over polymerisation activity for meso-catalysts than rac-catalysts, with meso-alkyl catalysts showing higher polymerisation activities than meso-halide. Below 70 °C, polymerisation activity follows the order sMAO-meso-((3-Et)Ind(#))(2)Zr(CH(2)Ph)(2,) sMAO-meso-((3-Et)Ind(#))(2)ZrCl(2) and sMAO-meso-((3-Et)Ind(#))(2)ZrBr(2) (activities of 657, 561, and 452 kg(PE) mol(M)(−1) h(−1) bar(−1), respectively). sMAO-meso-((3-Et)Ind(#))(2)ZrBr(2) produces HDPE with the highest molecular weight, followed by sMAO-meso-((3-Et)Ind(#))(2)ZrCl(2) and sMAO-meso-((3-Et)Ind(#))(2)Zr(CH(2)Ph)(2) (M(w) of 503, 406, and 345 kg mol(−1), respectively, at 50 °C). sMAO-meso-((3-Me)Ind(#))(2)ZrBr(2) produced HDPE with almost identical molecular weights to sMAO-meso-((3-Et)Ind(#))(2)ZrCl(2) (395 kg mol(−1) at 50 °C).