2-Ethyl-ketimino-1,10-phenanthroline iron(II) complexes as highly active catalysts for ethylene oligomerization

A series of 2-(1-aryliminopropyl)-1,10-phenanthrolines (L1–L7) and their corresponding iron(II) chlorides (Fe1–Fe7) are synthesized and characterized by elemental and spectroscopic analyses. The molecular structures of 2-[1-(2,6-diisopropy1phenylimino)propyl]-1,10-phenanthroline (L3) and {2-[1-(2,6-diethylphenylimino)propyl]-1,10-phenanthroline}·FeCl2 (Fe2) are determined by the single crystal X-ray diffraction. All iron complexes, activated with methylaluminoxane (MAO), exhibit high activities in ethylene oligomerization with high selectivity for α-olefins produced. Compared with other 2-imino-phenanthrolines, the title complexes show better thermal stability, and their oligomerization products are potentially more useful due to lower contents of butenes and waxes observed.

Graphical abstractThe 2-(1-arylimiopropyl)-1,10-phenanthrolines and their iron complexes are synthesized and sufficiently characterized by elemental and spectroscopic analyses. Activated by MAO, the title iron complexes with better thermal stability perform ethylene oligomerization with narrower distribution of oligomers.Figure optionsDownload full-size imageDownload high-quality image (43 K)Download as PowerPoint slide