Frustratingly synergic effect of cobalt-nickel heterometallic precatalysts on ethylene reactivity: the cobalt and its heteronickel complexes bearing 2-methyl-2,4-bis(6-aryliminopyridin-2-yl)-1H-1,5-benzodiazepines

摘要

A series of 2-methyl-2,4-bis(6-aryliminopyridin-2-yl)-1H-1,5-benzodiazepines were reacted with cobalt chloride to form their corresponding cobalt complexes, which were further reacted with nickel chloride to form their binuclear heteronickel complexes. One of the representative cobalt-nickel complexes was unambiguously confirmed using single-crystal X-ray diffraction. Generally all mononuclear cobalt complexes and binuclear cobalt-nickel complexes showed good activities towards ethylene reactivity (oligomerization and polymerization), however, the mononuclear cobalt complexes showed much higher activities than the binuclear cobalt-nickel analogues, and this is described as the frustratingly synergic effect of heterometallic complexes in ethylene oligomerization. In addition, the obtained oligomers sometimes followed a Poisson distribution.