Nickel(Ⅱ) Complex Bearing a Salicylaldimine Ligand:Synthesis,Crystal Structure and Application in Norbornene Polymerization

A novel salicylaldimine ligand and its mononuclear nickel complex NiL](L = 2-2,6-bis(diphenylmethyl)-4-methylphenyl]imino]methyl]phenol) have been synthesized and characterized by IR spectrum, elemental analysis and thermogravimetry(TG). The molecular structure of the complex has been measured by single-crystal X-ray diffraction analysis. The crystal belongs to the monoclinic system, space group P2_1/n with a = 13.281(3), b = 16.938(3), c = 13.981(3) ?, β = 97.03(3)o, V = 3121.2(11) ?~3, C_(80)H_(64)N_2O_2Ni, M_r = 1144.04, Z = 2, D_c = 1.217 Mg/m~3, μ = 0.361 mm~(-1), F(000) = 1204, the final R = 0.0582 and wR = 0.1108(I 2s(I)). The compound showed excellent catalytic activity up to 12.78 × 10~6 g of PNB(polynorbornene)(mol of Ni)~(-1) h~(-1) for the addition polymerization of norbornene(NB) by using methylaluminoxane(MAO) as a cocatalyst.