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 trid entate Schiff base {N-(2-methoxyphenyl)salicylideneamine} with tris(cyclope ntadienyl) lanthanide tetrahydrofuranate or bis(cyclopentadienyl) lanthanid e 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)) L n = Sm, Dy, Y, Er} (1-4) was further confirmed by X-ray determination of Cp 2Sm(C14H13NO2) (1) which indicates that the complex is monomeric in which c entral 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 methylc yclopentene. Similarly complexes {CpLn(Cl)C14H13NO2) (THF) (Ln = Sm, Dy, Y, Er)} (5-7) polymerize methylmethacrylate (MMA) to give polyMMA (PMMA) in 5 1.8% yield and high molecular weight (274 x 10(3)), which shows narrow mole cular weight distributions and partially syndiotactic.