Steric Control of Lanthanide Coordination Environment: (TpMe2)2Sm(C⋮CPh), a Monomeric, Base-Free Lanthanide Alkynide Complex, and Its Thermally Induced Transformation to (TpMe2){HB(Me2pz)2(C⋮CPh)}Sm(Me2pz)

Abstract

Reaction of Sm(TpMe2)2 (1) with Hg(C⋮CPh)2 in THF at ambient temperature afforded the monomeric, base-free lanthanide alkynide complex (TpMe2)2Sm(C⋮CPh) (2). Thermolysis of 2 in benzene resulted in clean transformation to the new complex (TpMe2){HB(Me2pz)2(C⋮CPh)}Sm(Me2pz) (3), the result of an interesting, unusual ligand rearrangement on the Sm(III) center. Complexes 2 and 3 have been fully characterized by spectroscopic methods and X-ray crystallography.