A new tetranuclear nickel complex based on the benzimidazole ligand for the controllable polymerization of methyl methacrylate

The new tetranuclear [Ni4(L)6Cl]⋅ Cl (1) complex from the benzimidazole-based ligand HL (HL: 2-(1H-benzo[d]imidazol-2-yl)-6-methoxyohenol) was prepared and structurally characterized by EA, FT-IR and X-ray single-crystal diffraction. The tetranuclear complex 1 was shown to efficiently catalyze the controllable polymerization of methyl methacrylate (MMA) in activation with AIBN (azobisisobutyronitrile), giving the syndio-enriched atactic PMMAs. The existence of two active species in the 1/AIBN systems should be favorable for the higher catalytic activities, while the cooperative interactions between the two active centers should result in the relatively broad molecular weight distributions for the obtained PMMAs.