Copolymerization of styrene with(Z)-1,3-pentadiene in the presence of a syndiotactic-specific catalyst

Copolymerization of styrene with (Z)-1,3-pentadiene affords copolymers mostly containing 1,2 pentadiene units. Both the styrene and the pentadiene units are in syndiotactic arrangement but the comonomer sequence distribution is far from bernoullian. Interestingly, the behavior of (Z)-1,3-pentadiene does not change much when polymerization temperature raises from -20 to +20 degrees C, notwithstanding that (Z)-1,3-pentadiene affords a 1,2-syndiotactic homopolymer at -20 degrees C but a prevailingly 1,4 cis homopolymer at +20 degrees C.