2-Substituted 8-(2-benzhydrylarylimino)-5,6,7-trihydroquinoline-N,N’ nickel dichlorides: Synthesis, characterization and catalytic behavior toward ethylene

A series of 2-substituted 8-(2-benzhydrylarylimino)-5,6,7-trihydro- quinolines (L) was synthesized and fully characterized, and their nickel chloride complexes, namely 2-substituted 8-(2-benzhydrylarylimino)-5,6,7-trihydroquinoline- N,N’ nickel dichlorides (LNiCl2), were prepared and characterized by FT-IR and elemental analysis. The structures of representative complexes were confirmed by single crystal X-ray crystallography, which revealed a distorted trigonal bipyramidal geometry at the metal for complexes Ni3 and Ni5 containing an additional solvent molecule, and a distorted tetrahedral geometry for the complex Ni8. Upon activation with methylaluminoxane (MAO), all nickel pre-catalysts showed good activity for ethylene polymerization and considerable activity for ethylene oligomerization.