Late transition metal catalysts with α-diimine ligands are known for a variety of functions, specifically polymerization of α-olefins such as 1-hexene. The polymers that are produced have varying degrees of branching and molecular weight resulting from variations that are found from ligand to ligand. The α-diimine ligands that were chosen were used to analyze the ortho position of the ligand to determine the different impacts on the degree of branching and molecular weight of the polymer. The specific ligands that were synthesized in this study are as follows:2-CF3-DABMe = N,N’-bis(2-(trifluoromethyl)phenyl)-2,3-dimethyl-1,4-diaza-1,3-butadiene, 2-Me-DABMe = N,N’-bis(2-(methyl)phenyl)-2,3-dimethyl-1,4-diaza-1,3-butadiene, and 2-tBu-DABMe = N,N’-bis(2-(tertbutyl)phenyl)-2,3-dimethyl-1,4-diaza-1,3-butadiene.  These were synthesized and reacted with (dme)NiBr2 (dme = dimethoxyethane) to give Ni(2-R-DABMe)Br2 (R = CF3 (1), Me (2), tBu (3)). Polymerization was initiated by the addition of a cocatalyst, methylaluminoxane (MAO). The molecular weight of the resulting polymer was determined by DOSY NMR and the degree of branching was determined by 1H NMR spectroscopy.

Steric and electronic effects of varying the ortho position of Ni(II) α-diimine catalysts on the properties of poly(1-hexene)

2019 Spring National Meeting

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