Nickel(II) Complexes Bearing NH2CH2CH2CH2NH2 and o-C6H4(NH2)2 Ligands: Synthesis, Structures and Their Ethylene Polymerization Behavior

Two nickel complexes [Ni(NH2CH2CH2CH2NH2)(3)]Cl-2 (1) and [Ni(C6H4N2H4)(2)Cl-2] (2) have been obtained and characterized by IR and single crystal X-ray diffraction analysis. In complex 1, the nickel atom was in a chiral pseudo-octahedral [NiN6] geometry environment, which was coordinated by three 1,3-propylenediamine to form three six-membered rings. However in complex 2, besides connected with two o-phenylenediamine through four Ni-N bonds to form two five-membered rings, the nickel center was coordinated by two Cl to form trans-Ni-Cl-2, which was different from general reported diimine nickel complexes. Activated with MAO, MMAO or Et2AlCl, these nickel complexes exhibited considerable good catalytic activity [up to 3.59 X 10(6) g.mol(-1).h(-1) for complex 2] for ethylene polymerization with main products as dimers or trimers of ethylene.