Bimetallic nickel complexes of trimethyl phenyl linked salicylaldimine ligands: Synthesis, structure and their ethylene polymerization behaviors

Bimetallic salicylaldimine-nickel complexes, 2,4,6-Me3-1,3-{[Ndouble bond; length as m-dashCH–(3′-R-5′-Y-2′-O–C6H3)-κ2-N,O]Ni(Ph) (PPh3)}2 [R = tert-Bu, Y = Me, 1b; R = Ph, Y = H, 2b] were prepared and their catalytic behaviors of ethylene polymerization were investigated. The bimetallic complex 2b shows higher activities (2.9 × 105 g PE mol−1 Ni h−1) for ethylene polymerization and affords polymer with high molecular weight (Mw = 1.41 × 105) and broad molecular weight distribution (Mw/Mn = 6.1) than its mononuclear matrix, {[(2,6-Me2C6H3)–Ndouble bond; length as m-dashCH–(3′-Ph-2′-O–C6H3)-κ2-N,O]Ni(Ph)(PPh3)} (3) (Activity = 5.5 × 104 g PE mol−1 Ni h−1; Mw = 1.86 × 104; Mw/Mn = 2.8).