Divalent β-diketiminate lanthanide complexes LYbR（THF）（L=｛（2,6-Me2C6H3）NC（Me）｝2CH;R=C9H7（1）,CH3C5H4（2）,OC6H2-But2-2,6-Me-4（32））were synthesized by reducing the mixed-ligand trivalen（t） β-diketiminate ytterbium chlorides synthesized in situ with Na-K alloy.These divalent lanthanide complexes exhibit good catalytic activity for the ring opening polymerization of ε-caprolactone.
