Lanthanide ions and complexes occupy a special position in developing synthetic nucleases capable of catalyzing the hydrolytic cleavage of RNA or DNA. Stimulated by a number of serendipitous lanthanide complexes that feature the common active-site structure of dinuclear metallo-phosphodiesterases, rational design and synthesis of polynuclear lanthanide–hydroxo species via ligand-controlled hydrolysis of the lanthanide ions were attempted. The efforts yielded a series of highly sophisticated yet structurally well-defined lanthanide–hydroxo complexes. These materials are potentially applicable to the study of biomimetic catalysis of phosphate diester cleavage. Research highlights are described in this Feature Article.

A nanosized heterometallic cluster containing 60 La(III) and 76 Ni(II) ions, which are arranged into a four-shell, nest-like framework structure, was obtained by the hydrolytic reaction of the mixed La(NO₃)₃–Ni(NO₃)₂ system using iminodiacetate as an ancillary ligand to control the hydrolysis.