Study on α- diimine ligand backbone in 1-hexene polymerization using late transition metal catalysts

Two Nickel-based catalysts of 1,4-bis(2,6-diisopropylphenyl)-butanediiminedichloro-nickel(II) (1a) and 1,4-bis(2,6 diisopropylphenyl)-acenaphthenediiminedibromo-nickel(II) (2a) was used in polymerization of 1-hexene. In order to study on the influence of reaction condition ([Al] /[Ni] molar ratio) and structure effect of catalyst (diimine backbone) on the activity and average molecular weight (Mv), experiments performed under identical manner. The results revealed that catalyst 1a produced poly (1-Hexene) with higher Mv and less activity than catalyst 2a using DEAC (diethylaluminium chloride) and ethylaluminum sesquichloride (EASC) as cocatalysts. Also the highest activity obtained for both catalysts using DEAC at [Al]/[Ni]=700. In addition, EASC demonstrated higher activity than DEAC at the same polymerization conditions for each catalyst.