α,ω-Dienes are an important class of monomers due to their utility in the synthesis of cyclopolyolefins and reactive polyolefin intermediates. In this contribution, the terpolymerization of two α,ω-dienes (i.e., 1,5-hexadiene and 1,7-octadiene) with ethylene and various cyclic olefins [i.e., norbornene (NB), 5-ethylidene-2-norbornene (ENB), and dicyclopentadiene (DCPD)] catalyzed by a chelated imido vanadium complex has been examined. The ENB and DCPD diene termonomers provide additional sites for post-polymerization functionalization. Vanadium-catalyzed terpolymerization of the investigated α,ω-dienes yields polyolefins with a high molecular weight (M_w up to 200 × 10³ g mol^–1), unimodal and narrow molecular weight distribution, subambient glass transition temperatures (−30 < T_g °C < −3), and a proper content of C═C bonds. Comprehensive NMR investigation of the obtained polymers revealed that subtle changes in the α,ω-diene size have important effects on the numerous combinations of insertion paths (ring closure vs ring opening), from which different repeating units with a C═C bond in the side or main polymer chain and cyclic units are installed. Finally, the poly(ethylene-ter-1,5-hexadiene-ter-NB) was subjected to thiol-ene addition using thioglycolic acid, methyl thioglycolate, and N-acetyl-l-cysteine to access polar-functionalized polyolefins with a degree of functionalization and properties dependent on the thiol substitution.

β-Myrcene was polymerized with catalysts based on pyridyl-imino complexes of neodymium, iron and copper to highly stereoregular polymers.

Some novel cobalt diphenylphosphine complexes were synthesized by reacting cobalt(II) chloride with (2-methoxyethyl)diphenylphosphine, (2-methoxyphenyl)diphenylphosphine, and 2-(1,1-dimethylpropyl)-6-(diphenylphosphino)pyridine. Single crystals suitable for X-ray diffraction studies were obtained for the first two complexes, and their crystal structure was determined. The novel compounds were then used in association with methylaluminoxane (MAO) for the polymerization of 1,3-butadiene, and their behavior was compared with that exhibited in the polymerization of the same monomer by the systems CoCl₂(PⁿPrPh₂)₂/MAO and CoCl₂(PPh₃)₂/MAO. Some significant differences were observed depending on the MAO/Co ratio used, and a plausible interpretation for such a different behavior is proposed.