High tacticity control in organolanthanide polymerization catalysis: formation of isotactic poly(alpha-alkenes) with a chiral C3-symmetric thulium complex

The thulium complexes Tm((i)Pr-trisox)(CH(2)SiMe(2)R)(3)] (R = Me , Ph ) were synthesized from the thulium trialkyl precursors Tm(CH(2)SiMe(2)R)(3)(thf)(2)]; reaction of with two equivalents of Ph(3)C]B(C(6)F(5))(4)] gave a cationic complex 1c, which was found to polymerize 1-hexene, 1-heptene and 1-octene to give the corresponding polyolefins with moderate to good activities and with minimum isotacticity of 90%, 83% and 95%, respectively.