Iron, cobalt and nickel complexes bearing hyperbranched iminopyridyl ligands: Synthesis, characterization and evaluation as ethylene oligomerization catalysts

摘要

Graphical abstractA series of hyperbranched iminopyridyl ligands and corresponding iron, cobalt and nickel complexes were synthesized, characterized and studied as catalyst for ethylene oligomerization. All complexes exhibited excellent catalytic properties for ethylene oligomerization. Meanwhile, the hyperbranched iminopyridyl nickel complex possessed better catalytic activity and selectivity of high carbon number olefins compared with iron and cobalt complexes.Display OmittedHighlights?New hyperbranched iminopyridyl iron, cobalt and nickel complexes were synthesized and characterized structurally.?The oligomers showed Schulz-Flory distribution when nickel complexes combination with MAO.?Upon activation with EtAlCl2, the nickel complex exhibited higher catalytic activities, and the alkylated-toluenes were mainly products.?The hyperbranched iminopyridyl nickel complex exhibited better