Synthesis, structure and catalytic behavior of ytterbium complexes bearing a phenoxy(quinolinyl)amide ligand

Two ytterbium complexes stabilized by phenoxy(quinolinyl)amide ligand 3,5-But2-2-OC6H2CH2N-8-C9H6N (L) were synthesized and characterized. Reaction of anhydrous YbCl3 with 1 equiv. of LLi2 in THF gave the ytterbium chloride [LYbCl(THF)]2 (1) in 73% yield. A further reaction of complex 1 with equimolar of NaN(SiMe3)2 in THF afforded the unexpected heterobimetallic “ate”-complex L2YbNa(THF)2 (2) via a ligand redistribution reaction. Complex 2 could also be prepared in high isolated yield by the reaction of anhydrous YbCl3 with 2 equiv. of LNa2 generated in situ. Both complexes 1 and 2 were characterized by IR spectroscopy, elemental analysis, and single-crystal X-ray diffraction analysis. It was found that complex 2 was an effective catalyst for the addition reaction of aromatic amines to carbodiimides.