The half‐sandwich complexes, [η1:η5‐C9H6(CH2)2NEt]Ti(NEt2)2 and [η1:η5‐C13H8(CH2)2NEt]Ti(NEt2)2, were synthesized and characterized by spectroscopy techniques. These compounds were activated by methylaluminoxane (MAO) for homogeneous ethene polymerization. The effect of the ligand and Al/Ti molar ratio on the polymerization activity, the molecular masses and the thermal properties of the polymers were studied and compared with previous data obtained for the case of analogous cyclopentadienyl (Cp) complexes. The activity and molecular weight decreases in the following order: Cp‐half‐sandwich > indenyl‐half‐sandwich > fluorenyl‐half‐sandwich, as consequence of the interaction of steric and electronic effects.

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The complexes [CpTi(NR2)3] were tested in ethene polymerisation and the effect of the alkyl-amine groups on their activities was explored.

Abstract-Metallocene complexes Cp 2 TiCl 2 , Cp 2 ZrCl 2 , Cp 2 Zr(N n Bu 2 ) 2 , Cp 2 Ti(η 1 -OC(O)C 6 H 5 ) 2 and Cp 2 Zr(η 1 -OC(O)C 6 H 5 ) 2 were supported on MgCl 2 /SiCl 4−n (n-C 6 H 13 O) n carrier and used for ethylene polymerization. The supported complexes result in highly active catalysts when treated with different aluminum alkyl-based co-catalysts. These catalysts are able of tuning the final properties of the produced polyethylenes. Mixed composites of metallocenes and conventional Ziegler-Natta catalysts supported on the same carrier were also studied. A supported zirconocene Cp 2 Zr(η 1 -OC(O)C 6 H 5 ) 2 on MgCl 2 /SiCl 4−n (n-C 6 H 13 O) n resulted in a highly active catalyst that eject control on the molecular weight, crystallinity and morphology of the resultant polyethylene.

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