Dinuclear Nickel(Ⅱ) Chlorides Bearing N,N′-bis(5,6,7-trihydroquinolin-8-ylidene)-[1,1′-biphenyl]-4,4′-diamines: Synthesis and Ethylene Polymerization

5,6,7-Trihydroquinolin-8-one was condensed with the corresponding benzidine to give N,N′-bis(5,6,7-trihydroquinolin-8-ylidene)-1,1′-biphenyl]-4,4′-diamine derivatives(L1–L3). The ligands were reacted with two equivalents of Ni Cl_2·6H_2O in a mixture of Et OH and CH_2Cl_2 to afford the corresponding dinickel(II) chloride complexes(Ni1-Ni3). The organic compounds were completely characterized, whilst the bi-metallic complexes were characterized by FTIR spectra and elemental analysis. These nickel complexes exhibited high activities towards ethylene polymerization in the presence of either MAO or Me_2AlCl, maintaining a high activity over a prolonged period. The obtained polyethylenes were confirmed as having low molecular weights by GPC analysis.