Alternating Ethene/Propene Copolymerization with a Metallocene Catalyst

A small variation in the substituent R′ on the metallocene catalyst employed in the copolymerization of ethene and propene leads to a highly alternating (81–83%) structure ( 1 ) rather than a statistical copolymer. Such copolymers were until recently only accessible by hydrogenation of polyisoprene or 1,4-poly(pentadiene).