Synthesis of anilinonaphthoquinone-based nickel complexes and their application for olefin polymerization

A series of anilinonaphthoquinone-based nickel complexes, Ni(C10H5O2NAr)(Ph)(PPh3) (Ar = C6H3-2,6-Me (1c); Ar = C6H2-2,4,6-Me (2c); Ar = C6H3-2,6-Et (3c)), were synthesized and the structures of 1c–3c were confirmed by single crystal X-ray analyses. The anilinonaphthoquinone-ligated nickel complexes activated with B(C6F5)3 showed high activities for ethylene polymerization at 40 °C under atmospheric pressure of ethylene and gave polyethylene with long chain branches and short chain branches. The activity of these systems was decreased by lowering polymerization temperature accompanied by increase in molecular weight. The number of the chain branches was also decreased with lowering polymerization temperature and increasing the bulkiness of the ligand.

Graphical abstractA series of anilinonaphthoquinone-based nickel complexes were synthesized and the structures were confirmed by single crystal X-ray analyses. The nickel complexes activated with B(C6F5)3 showed good activities for ethylene polymerization under atmospheric pressure.Figure optionsDownload full-size imageDownload as PowerPoint slide