A Novel Phenoxyimine-based Schiff Base Ligand and Its Mononuclear Nickel(Ⅱ) Complex:Synthesis,Crystal Structure,Norbornene Polymerization and Catalytic Activity

A novel phenoxyimine-based Schiff base ligand and its mononuclear complex [C_(58)H_(52)N_2NiO_2](L = 2-benzhydryl-4-dimethoxy-3,5-dimethyl-salicylaldehyde) has been synthesized and characterized by IR spectrum, elemental analysis, TG, WAXD spectra, ~1H NMR and ~(13)C NMR. In addition, the molecular structure has been measured by single-crystal X-ray diffraction analysis. The crystal belongs to the monoclinic system, space group P2_1/c with a = 14.510(6), b = 18.573(7), c = 20.961(6) ?, β = 123.453(19)°, V = 4713(3) ?~3, M_r = 867.73, Z = 4, D_c = 1.223 g/cm~3, μ = 0.456 mm~(-1), F(000) = 1832, the final R = 0.0685 and wR = 0.1758(I 2σ(I)). The complex was used as homogeneous catalysis of polymerization of norbornene, and the MAO as cocatalyst. The nickel complex exhibited good catalytic activity up to 1.913 × 10~7 g of PNB(mol of Ni)~(-1)h~(-1),and the yields of these reactions depend on the nature of the substituent in the aromatic ring.