Novel Controlled Polymerization of Cyclo-olefins, Dienes, and Trienes by Utilizing Reaction Properties of Late Transition Metals

Pd complexes with diimine ligands promote polymerization of cyclopentenes, 1,6‐dienes, and 1,6,11‐trienes to afford polymers having 1,2‐ or 1,3‐five‐membered ring in every repeating unit. The Pd complexes with C2 symmetrical structure catalyze the polymerization reactions to produce polymers with high stereoselectivity. Some of the obtained polymers show characteristic properties such as thermoreversible gelation and liquid crystal formation. Ni complexes bring about the cyclopolymerization of the dienes to afford polymers containing five‐ and/or six‐membered rings in controlled stereochemistry. Diimine Pd complexes promote polymerization of cyclopentenes, non‐conjugated dienes, and trienes to produce polymers with controlled structure. The polymers show characteristic properties including thermoreversible gelation and liquid crystalline formation. Diimine Ni complexes bring about cyclopolymerization of diallylfluorene to yield polymers containing five‐ and/or six‐membered rings in controlled stereochemistry.