Yttrium complexes stabilized by a diaminobis(phenolate) ligand were synthesized and their catalytic behavior was explored. Reaction of YCl3 with 1 equiv of LNa2 [L= Me2NCH2CH2N{CH2-(2-O-C6H2-tBu2-3, 5)}2] gave the yttrium chloride LYCl(THF) (1) in 92% yield. Complex 1 can be used as starting material to prepare the yttrium amido derivative. Complex 1 reacted with 1 equiv of LiNPh2 in THF to afford the expected yttrium amido complex LYNPh2 (2) in high yield. Both of complexes 1 and 2 have been well detected by elemental analysis, NMR spectra and single-crystal X-ray analysis. It was found that complex 2 can efficiently initiate the ring-opening polymerization of L-lactide and ε-caprolactone, and a controlled manner is observed in the former case.
SONG FengKui YAN ChunHui SUN HongMei YAO YingMing SHEN Qi ZHANG Yong
The synthesis and characterization of dimeric rareearth amides stabilized by a dianionic N-aryloxo functionalized β-ketoiminate ligand are described.Reactions of 4-(2-hydroxy-5-methyl-phenyl) imino-2-pentanone(LH2) with Ln[N(SiMe3)2]3(μ-Cl)Li(THF)3 in a 1:1 molar ratio in THF gave the dimeric rare-earth amido complexes [LLn{N(SiMe3)2}(THF)]2 [Ln = Nd(1),Sm(2),Yb(3),Y(4)].These complexes were well characterized,and the definitive molecular structures of complexes 3 and 4 were determined.It was found that complexes 1― 4 can initiate the ring-opening polymerization of ε-caprolactone,and the ionic radii of the central metals have significant effect on the catalytic activity.
HAN XiangZong WU LiangLiang YAO YingMing ZHANG Yong SHEN Qi
The synthesis,characterization and luminescent properties of aluminum complexes containing a dianionic N-aryloxo functionalized β-ketoiminate ligand are presented.4-(2-Hydroxy-5-R-phenyl)imino-2-pentanone (R=Me,L 1 H 2;R=tert-butyl,L 2 H 2) ligands reacted with AlEt 3 in tetrahydrofuran to give the aluminum complexes (L 1 AlEt) 2 (1) and (L 2 AlEt) 2 (2) in reasonable isolated yields.X-ray diffraction revealed that complexes 1 and 2 have solvent-free centrosymmetric dimeric structures,and each aluminum center has distorted trigonal bipyramidal geometry.At room temperature,complexes 1 and 2 exhibit blue photoluminescence in acetonitrile with maximum emission wavelengths of 419 and 413 nm,respectively.
