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 C-2 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.