Novel polymerization and copolymerization of ethylene, styrene, and/or butadiene by new organolanthanide-based catalysts

Replacement of one of the two C5Me5 ligands in the samarocene(II) complex ( C5Me5)(2)Sm(THF)(2) with a monodentate anionic ligand (e.g., OAr, SAr, or ( NRR2)-R-1) gives a unique catalytic system, which can not only polymerize s tyrene and ethylene, but also copolymerize them into block styrene-ethylene copolymers under the presence of both monomers. On the other hand, additio n of an appropriate cocatalyst such as MMAO or AlR3/[Ph3C] [B(C6F5)(4)] to the samarocene complex (C5Me5)(2)Sm(THF)(2) or (C5Me5)(2)Sm(mu -Me)(2)AlMe2 affords a novel catalytic system for stereospecific 1,4-cis living polymer ization of butadiene and copolymerization of butadiene with styrene.