Synthesis, Structure, and Catalytic Behavior of Ytterbium Complexes Derived from a Linked Bis(β‐ketoiminato) Ligand

Ytterbium complexes supported by a linked bis(β‐ketoiminato) ligand, N , N ′‐ethylenebis(benzoylacetoimine) (H 2 L), were synthesized and their catalytic behavior was explored. The reaction of YbCl 3 with 1 equiv. of LLi 2 afforded the mononuclear ytterbium chloride LYbCl(THF) 2 ( 1 ) in high yield. Complex 1 can be used as starting material to prepare β‐ketoiminate‐ytterbium derivatives. Treatment of complex 1 with NaN(SiMe 3 ) 2 produced the dimeric ytterbium amide {LYb[N(SiMe 3 ) 2 ]} 2 ( 2 ), while the similar reaction of complex 1 with NaOAr (ArO = 2, 6‐ t Bu‐4‐MeC 6 H 2 O) led to the mononuclear ytterbium aryloxide LYbOAr(THF) ( 3 ). The three complexes were well detected by elemental analysis and single‐crystal X‐ray analysis. It was found that complexes 2 and 3 can initiate the ring‐opening polymerization of ϵ‐caprolactone with moderate activity.