Synthesis, characterization and catalytic applications of tridentate Schiff base derivatives of bis and mono (cyclopentadienyl)lanthanocene complexes

Seven kinds of lanthanocene complexes were prepared by the reaction of tridentate Schiff base {N-(2-methoxyphenyl)salicylideneamine} with tris(cyclopentadienyl) lanthanide tetrahydrofuranate or bis(cyclopentadienyl) lanthanide chloride tetrahydrofuranate in THF. All the complexes were characterized by MS, EA and IR respectively. The structure of {Cp(2)LnCl(14)H(13)NO(2)) Ln = Sm, Dy, Y, Er} (1-4) was further confirmed by X-ray determination of Cp2Sm(C14H13NO2) (1) which indicates that the complex is monomeric in which central metal is coordinatively saturated by two cyclopentadienyl rings, two oxygens and one nitrogen of the ligand. The isomerization of 1,5-hexadiene explains that complexes (1-4) isomerize this monomer into a mixture of 1,4-hexadiene, 2,4-hexadiene, 1,3-hexadiene, methylenecyclopentane and methylcyclopentene. Similarly complexes {CpLn(Cl)C14H13NO2) (THF) (Ln = Sm, Dy, Y, Er)} (5-7) polymerize methylmethacrylate (MMA) to give polyMMA (PMMA) in 51.8% yield and high molecular weight (274 x 10(3)), which shows narrow molecular weight distributions and partially syndiotactic.