title: Synthesis, characterization, and catalytic activity of rare earth metal amides supported by a diamido ligand with a CH2SiMe2 link.
abstract: A series of four coordinate rare earth metal amides with general formula ((CH2SiMe2)[(2,6- IPr2C6H3)N]2)LnN(SiMe3)2(THF) [(Ln = Yb(2), Y (3), Dy (4), Sm (5), Nd (6)] containing a diamido ligand (CH2SiMe2)[(2,6-iPr2C6H3)N]2(2-) with a CH2SiMe2 link were synthesized in good yields via reaction of [(Me3Si)2N]3Ln(III)(mu-Cl)Li(THF)3 with the corresponding diamine (CH2SiMe2)[(2,6-iPr2C6H3)NH]2 (1). All compounds were fully characterized by spectroscopic methods and elemental analyses. The structures of complexes 2, 3, 4, 5, and 6 were determined by single-crystal X-ray analyses. Investigation of the catalytic properties of the complexes indicated that all complexes exhibited a high catalytic activity on the cyclotrimerization of aromatic isocyanates, which represents the first example of cyclopentadienyl-free rare earth metal complexes exhibiting a high catalytic activity and a high selectivity on cyclotrimerization of aromatic isocyanates. The temperatures, solvents, catalyst loading, and the rare earth metal effects on the catalytic activities of the complexes were examined.
authors.affiliation: Institute of Organic Chemistry, Anhui Key Laboratory of Functional Molecular Solids, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui, P.R. China.
authors.forename: Yunjun
authors.initials: Y
authors.lastname: Wu
authors.forename: Shaowu
authors.initials: S
authors.lastname: Wang
authors.forename: Xiancui
authors.initials: X
authors.lastname: Zhu
authors.forename: Gaosheng
authors.initials: G
authors.lastname: Yang
authors.forename: Yun
authors.initials: Y
authors.lastname: Wei
authors.forename: Lijun
authors.initials: L
authors.lastname: Zhang
authors.forename: Hai-bin
authors.initials: HB
authors.lastname: Song