Synthesis, Characterization, and Ethylene Oligomerization and Polymerization of [2,6-Bis(2-benzimidazolyl)pyridyl]chromium Chlorides

A series of [2,6-bis(2-benzimidazolyl)pyridyl]chromium chlorides have been synthesized and characterized by elemental analysis and IR spectroscopy, along with X-ray diffraction analysis for the structures
of C1 and C7. When methylaluminoxane (MAO) was employed as the cocatalyst, the chromium complexes
showed high activity for ethylene oligomerization and polymerization. Oligomers were produced with
high selectivity for α-olefins, and polyethylenes were generated with extremely broad molecular weight
distributions. In the presence of diethylaluminum chloride (Et2AlCl), these chromium complexes showed
moderate activity for ethylene polymerization and produced high-molecular-weight linear polyethylene.