Cyclopolymerization of 1,6-Heptadienes Catalyzed by Iron and Cobalt Complexes: Synthesis of Polymers with Trans- or Cis-Fused 1,2-Cyclopentanediyl Groups Depending on the Catalyst

The Fe and Co complexes with a bis(imino)pyridine ligand promote the polymerization of 1,6-heptadienes with quantitative cyclization to yield polymers containing five-membered rings. The polymers composed of cis-fused five-membered rings and trans-fused rings are obtained selectively by choosing the catalyst.