Synthesis and Structural Characterization of Mixed-Valent Ytterbium and Europium Complexes Supported by a Phenoxy(quinolinyl)amide Ligand

The formation of mixed-valent ytterbium and europium complexes L4LnIII2LnII (Ln = Yb (1), Eu (2)) was observed for the first time in the spontaneous reduction reaction system of quinolinyl aminophenol (H2L) with Ln­[N­(SiMe3)2]3 (Ln = Yb, Eu) in toluene at 90 °C, whereas the same reaction with Sm­[N­(SiMe3)2]3 gave the expected monoamido samarium complex LSmN­(SiMe3)2(DME) (4). The isolation of the binuclear ytterbium complex L3Yb2 (3) under mild conditions demonstrates that the transformation from a trivalent ytterbium complex to the mixed-valent ytterbium species 1 may involve a ligand redistribution reaction and homolysis of the Yb–N bond.