Synthesis, crystal structure of [(MeC5H4)2Ln(μ-OCH2CH2NMe2)]2 (Ln = Sm, Y, Nd) and their catalytic activity for ring-opening polymerization of ε-caprolactone

Reaction of (MeC5H4)(3)Ln with HOCH2CH2NMe2 in tetrahydrofuran ( THF) gives the new complexes [(MeC5H4)(2)Ln(mu-OCH2CH2NMe2)](2)(Ln = Sm, Y, Nd) with nitrogen functionalized mu-alkoxide ligand. The complexes were characterized by elemental analysis and IR, and [(MeC5H4)(2)Sm(mu-OCH2CH2NMe2)](2) was structurally characterized by the X-ray diffraction to be a dimer formed by two unsymmetric oxygen bridges. The complex has a tricyclic skeleton with the additional two Sur - N bonds via intramolecular coordination of OCH2CH2NMe2. The coordination number of the central metal Sur is nine. The title complexes show good catalytic activity for ring-opening polymerization of epsilon-eaprolactone.