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

Abstract Ytterbium complexes supported by a linked bis(β‐ketoiminato) ligand,N,N′‐ethylenebis(benzoylacetoimine) (H2L), were synthesized and their catalytic behavior was explored. The reaction of YbCl3with 1 equiv. of LLi2afforded the mononuclear ytterbium chloride LYbCl(THF)2(1) in high yield. Complex1can be used as starting material to prepare β‐ketoiminate‐ytterbium derivatives. Treatment of complex1with NaN(SiMe3)2produced the dimeric ytterbium amide {LYb[N(SiMe3)2]}2(2), while the similar reaction of complex1with NaOAr (ArO = 2, 6‐tBu‐4‐MeC6H2O) 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 complexes2and3can initiate the ring‐opening polymerization of ϵ‐caprolactone with moderate activity.