Pure and Applied Chemistry

Abstract: Replacement of one of the two C₅Me₅ ligands in the samarocene (II) complex (C₅Me₅) ₂Sm (THF) ₂ with a monodentate anionic ligand (e. g. , OAr, SAr, or NR¹R²) gives a unique catalytic system, which can not only polymerize styrene and ethylene, but also copolymerize them into block styrene-ethylene copolymers under the presence of both monomers. On the other hand, addition of an appropriate cocatalyst such as MMAO or AlR₃/[Ph₃C][B (C₆F ₅) ₄] to the samarocene complex (C₅Me₅) ₂Sm (THF) ₂ or (C₅Me₅) ₂Sm (m-Me) ₂AlMe₂ affords a novel catalytic system for stereospecific 1,4-cis living polymerization of butadiene and copolymerization of butadiene with styrene.