Synthesis, characterization and ethylene oligomerization studies of nickel complexes bearing 2-imino-1,10-phenanthrolines

A series of nickel (II) complexes ligated by 2-imino-1,10-phenanthrolines were synthesized and characterized by elemental and spectroscopic analysis as well as by single-crystal X-ray crystallography. X-ray crystallographic analysis reveals complexes 3, 5, 7 and 11 as the five-coordinated distorted trigonal-bipyramidal geometry. Upon activation with Et2AlCl, these complexes exhibited considerably high activity for ethylene oligomerization (up to 3.76 × 107 g mol−1(Ni) h−1 for 12 with 10 equiv. of PPh3). The ligand environment and reaction conditions significantly affect the catalytic activity of their nickel complexes.

Graphical abstractA series of nickel (II) complexes ligated by 2-imino-1,10-phenanthrolines were synthesized and characterized by elemental and spectroscopic analysis as well as the single-crystal X-ray crystallography. X-ray crystallographic analysis reveals nickel complexes as the five-coordinated distorted trigonal-bipyramidal geometry. Upon activation with Et2AlCl, these complexes exhibited considerably high activity for ethylene oligomerization.Figure optionsDownload full-size imageDownload as PowerPoint slide