Synthesis, Structure Of Bridged Aryloxo Lanthanide Complexes

Some neutral lanthanide complexes supported by amine-bridged bis(phenolate) andbridged tri(phenolate) were synthesized and well characterized. The ligands used areMe₂NCH₂CH₂N{CH₂-(2-O-C₆H₂-Bu₂^t-3,5)}₂ and Me₂NCH₂CH₂N{CH₂-(2-O-C₆H₂-Me-5-Bu^t-3)}₂) and N, N, N'-tris-(3,5-di-tert-butyl-2-hydroxybenzyl)-benzene-1,2-diamine)They are abbreviated as L¹ ,L², and L.1. Reaction of LnCp₃(THF) with ligands L¹, L² in THF in a 1:1 molar ratio affordedneutral complexes L²LnCp(THF) (Ln=Sm (1), La (2)), and L¹ LaCp(THF) (3).Complexes 1-3 were characterized by IR and elemental analysis; and X-ray crystalstructure determination. These complexes can initiate the polymerization ofε-caprolactone.2. Reaction of YbCp₃(THF) with PhCH₂OH in THF in a 1:1 molar ratio, then furtherreacted with ligand L¹ in THF in a 1:1 molar ratio afforded amine-bridgedbis(phenolate) ytterbium alkoxide L¹ Yb(OCH₂Ph)(THF) (4). Complex 4 was wellcharacterized by IR and elemental analysis and X-ray structure determination. Thiscomplex can initiate the ring-opening polymerization ofε-caprolactone in goodactivity.3. First we synthesize ligand L(5).Reaction of Yb(ArO)₃ (ArO=2,4,6-Me-C₆H₂) with Lin THF in a 1:1 molar ratio afforded neutral complex LYb(THF) (6). The reactions ofLnCp₃(THF) with ligand L in THF afforded the neutral complexes LLn(DME)₂ (Ln= Sm (7), Nd (8), La (9)). Complexes 6-9 were well characterized by IR and elementalanalysis, and X-ray structure determination.