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

Abstract

The reaction of (α-diimine)NiMe 2 (α-diimine = (2,6-i Pr 2 -C 6 H 3 )NCMeMeCN(2,6-i Pr 2 -C 6 H 3 )) with partially dehydroxylated sulfated zirconia (SZO 300 ) in MeCN results in the formation of [(αdiimine)NiMe(NCMe)][SZO 300 ] ([1][SZO 300 ]) and methane. Reactions in Et 2 O resulted in mixtures of [(α-diimine)NiMe(OEt 2 )][SZO 300 ] ([2][SZO 300 ]) and [(α-diimine)NiMe(OEt 2 )][MeSZO 300 ] ([2]-[MeSZO 300 ]), 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][SZO 300 ] and [2][SZO 300 ]/[2][MeSZO 300 ] are active ethylene polymerization catalysts and show properties similar to those of closely related homogeneous catalysts. [2][SZO 300 ]/[2][MeSZO 300 ] copolymerizes ethylene and methyl 10-undecenoate to form copolymers with up to 0.4% incorporation of the polar monomer.

A simple and versatile nickel platform for the generation of branched high molecular weight polyolefins

“…The heterogenization of early transition metal catalysts has been extensively studied, and many systems have been successfully commercialized 55,56 . In comparison, very few studies on the heterogenization of late transition metal catalysts have been reported [57][58][59][60][61] . A homogeneous catalyst supported on a solid support can lead to serious steric crowding and complications due to side reactions, which could greatly reduce catalytic activities 62 .…”

A continuing legend: the Brookhart-type α-diimine nickel and palladium catalysts

“…Conley and co-workers prepared some sulfated zirconia supported α-diimine nickel catalysts and applied them in ethylene copolymerization with methyl 10-undecenoate. 168 Plenio and co-workers designed some bowl-shaped diimine nickel catalysts with two pentiptycenyl-substituents, and studied their properties in ethylene copolymerization with various comonomers including methyl 10-undecenoate. 169…”

Surface Organometallic Chemistry of Supported Iridium(III) as a Probe for Organotransition Metal–Support Interactions in C–H Activation

“…16 More recently, an α-diimine nickel complex supported on sulfated zirconia was found to be active for ethylene polymerization. 17 In all cases, the metal complexes supported on solid acids are characterized by highly electrophilic metal centers, in which the acidic support acts as a weakly coordinating anion for the cationic or partially cationic metal centers. 18…”