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. © 2013 American Chemical Society.