Bis(3-butenyl)zinc (BBZ) and bis(7-octenyl)zinc (BOZ) were synthesized from ZnCl2 and the Grignard reagent prepared from the corresponding bromide. Propene polymerization was conducted with TiCl3 using those compounds as cocatalyst. The activity strongly depended on the kind of cocatalyst and increased in the following order BBZ < BOZ < AlEt(2)Cl. These catalyst systems gave isotactic polypropylenes whose melting points were around 160 degrees C. The bis(omega-alkenyl)zinc compounds acted as a chain transfer reagent to give zinc-terminated polymers with low molecular weights. IR,H-1 NMR, and C-13 NMR analyses of the produced polymers indicated incorporation of the 7-octenyl group at the initiation chain end, whereas the 3-butenyl group was not observed, probably due to back-biting cyclization. BOZ copolymerized with propene to give PP having hexylzinc groups as side chains, while BBZ did not. The zinc-carbon bonds at the termination end as well as the side chain were converted to vinyl groups by coupling with allyl bromide to give alpha,omega-divinyl isotactic polypropylene with pendant 8-nonenyl groups.