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

Abstract Two nickel complexes [Ni(NH 2 CH 2 CH 2 CH 2 NH 2 ) 3 ]Cl 2 ( 1 ) and [Ni(C 6 H 4 N 2 H 4 ) 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 [NiN 6 ] 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 Et 2 AlCl, these nickel complexes exhibited considerable good catalytic activity [up to 3.59×10 6 g·mol −1 ·h −1 for complex 2 ] for ethylene polymerization with main products as dimers or trimers of ethylene.