Probing the Characteristics of Mono- or Bimetallic (Iron or Cobalt) Complexes Bearing 2,4-Bis(6-iminopyridin-2-yl)‑3H‑benzazepines: Synthesis, Characterization, and Ethylene Reactivity

A series of 2,4-bis­(6-iminopyridin-2-yl)-3H-benzazepines and the mono- or bimetallic (Fe2+ or Co2+) complexes thereof were synthesized and characterized. All title complexes, when activated by MAO or MMAO, exhibited high activities of up to 4.0 × 107 g (mol of Fe)−1 h–1 for ethylene oligomerization and polymerization. The iron­(II) precatalysts generally showed higher activities and produced a wider distribution of products (including oligomers and polyethylene) than did their corresponding cobalt­(II) analogues. The bimetallic precatalysts exhibited higher (almost twice) activities in comparison to their monometallic analogues. The distribution of the resulting oligomers closely resembled the Schultz–Flory rule.