A Well-Defined Ni(II) α‑Diimine Catalyst Supported on Sulfated Zirconia for Polymerization Catalysis

The reaction of (α-diimine)­NiMe₂ (α-diimine = (2,6-ⁱPr₂-C₆H₃)­NCMeMeCN­(2,6-ⁱPr₂-C₆H₃)) with partially dehydroxylated sulfated zirconia (SZO₃₀₀) in MeCN results in the formation of [(α-diimine)­NiMe­(NCMe)]­[SZO₃₀₀] ([1]­[SZO₃₀₀]) and methane. Reactions in Et₂O resulted in mixtures of [(α-diimine)­NiMe­(OEt₂)]­[SZO₃₀₀] ([2]­[SZO₃₀₀]) and [(α-diimine)­NiMe­(OEt₂)]­[MeSZO₃₀₀] ([2]­[MeSZO₃₀₀]), which were characterized by solid-state NMR spectroscopy. Contacting these solids with ethylene and monitoring the reaction by solid-state NMR showed that Ni–Me sites insert ethylene. [1]­[SZO₃₀₀] and [2]­[SZO₃₀₀]/[2]­[MeSZO₃₀₀] are active ethylene polymerization catalysts and show properties similar to those of closely related homogeneous catalysts. [2]­[SZO₃₀₀]/[2]­[MeSZO₃₀₀] copolymerizes ethylene and methyl 10-undecenoate to form copolymers with up to 0.4% incorporation of the polar monomer.