Synthesis and structure of a “living” copolymer of propylene and 1,5‐hexadiene

A soluble V(acac) 3 /Al(C 2 H 5 ) 2 Cl system was found to polymerize 1,5‐hexadiene to give a living polymer in toluene at −78°C. Hydrogenation of poly(1,5‐hexadiene) was conducted to determine the chain microstructure. The 13 C NMR analysis of hydrogenated poly(1,5‐hexadiene) indicated that the poly(1,5‐hexadiene) is composed of alternating units of 1,3‐cyclopentylenemethylene and 1‐vinyltetramethylene. In addition, living copolymers of propylene and 1,5‐hexadiene were prepared and characterized by analysis of the 1 H and 13 C NMR spectra. A chain propagation mechanism of living poly(1,5‐hexadiene) is proposed.