Iron(II) and cobalt(II) tris(2-pyridyl)phosphine and tris(2-pyridyl)amine catalysts for the ethylene polymerization

Polyethylene was synthesized using iron(II) and cobalt(II) complexes stabilized by tris(2-pyridyl)X (X = N, P) ligands in the presence of methylaluminoxane (MAO) as cocatalyst. The catalysts showed activities ranging from moderate to high. The iron complexes showed higher activities than the cobalt analogous and it was found that the bridgehead atom of the ligand tpX (X = P, N) did not affect significantly the activity of the active species as well as the molecular weight of the polymers. The polyethylenes obtained were classified as HDPE with linear structure and broad monomodal distribution.

Graphical abstractIron(II) and cobalt(II) catalysts based on tris(2-pyridyl)amine and tris(2-pyridyl)phosphine ligands have been prepared. These catalysts showed moderate to high catalytic activity toward ethylene polymerization. The iron complexes showed higher activities than the cobalt analogous. The polyethylenes were classified as HDPE with linear structure and broad monomodal distribution. Figure optionsDownload full-size imageDownload as PowerPoint slide