Synthesis of homoleptic, divalent lanthanide (Sm, Eu) complexes via oxidative transmetallation

The direct synthesis of neutral, divalent samarium and europium complexes supported by the bulky bis(tris-tert-butoxysilyl)amide (BTTSA) ligand via oxidative transmetallation is reported. Through the use of a copper(i) ligand complex, conventional lanthanide halide starting materials for complex formation are circumvented and the clean formation of divalent complexes is achieved directly from the bulk metal. The structures of the [Ln(BTTSA)(2)] (Ln = Sm, Eu) complexes are isotypic, presenting divalent lanthanide ions with distorted, six-coordinate geometries.