Preferential Crystallization of Lanthanoid Tris(β-diketonates) with Bridged Bis(2-pyridylmethyl)amine Ligands toward Separation Application

A combination of two bridged bis(2-pyridylmethyl)amine-type ligands offered efficient separation of lanthanoid tris(β-diketonates) complexes. The employed ligands bridged two lanthanoid tris(β-diketonates) to form crystalline ternary complexes. Since the complexes containing larger lanthanoid centers were preferentially precipitated, the bridging ligands selectively recognized the lanthanoid tris(β-diketonates) in the crystallization process, and offered an efficient separation method.