Copolymerization of Ethylene and Long-Chain Functional α-Olefins by Dinuclear Zirconium Catalysts

Abstract

Bimetallic catalysts have shown promise for improving polar comonomer incorporation by late transition metals, but such effects are underexplored using early transition metal catalysts. Herein, the copolymerization of ethylene and α-olefins bearing alcohol groups was performed using mono- and dizirconium bisamine bisphenolate catalysts in the presence of MAO and Al^iBu₃. Under these conditions, catalyst activity was retained with comonomer incorporation trends mirroring those observed with unfunctionalized α-olefins, i.e., lower incorporation by bimetallic catalysts. Although incorporation levels are low, these data provide mechanistic insight for polar comonomer incorporation. These results are consistent with our earlier proposal that larger comonomers sterically clash with the distal metal center of the bimetallic catalysts, leading to lower incorporation. Additionally, a bimetallic mechanism for polar comonomer coordination and incorporation is not supported by the current data.