Two bis-[1-(aryliminomethyleny)-2-oxy-naphthalen] nickel catalysts for the polymerization of methyl methacrylate

Abstract Two bis-(1-arylliminomethylenyl-2-oxy-naphthalen) nickel complexes (aryl = 2-methylphenyl, complex 1 ; aryl = 2,6-diisoproylphenyl, complex 2 ) were reacted with alkylaluminium in presence of equimolar PPh 3 and tested as catalysts in methyl methacrylate (MMA) polymerization. The two nickel catalysts can initiate polymerization of MMA with good to high activity, the highest activity reaching 1.1 × 10 5  g PMMA/(mol Ni · h) by less bulky complex 1 at 0.8 mol/L of MMA, 400 of Al/Ni ratio and 0 °C. In addition, the structures of nickel complexes and polymerization conditions, such as monomer concentration, polymerization temperature and Al/Ni molar ratio on catalytic activity of polymerization have great influences on catalytic activity and product properties.