Assembly of Dy and Dy cage-shaped nanoclusters.

Rapid kinetics, complex and diverse reaction intermediates, and difficult screening make the study of assembly mechanisms of high-nuclearity lanthanide clusters challenging. Here, we synthesize a double-cage dysprosium cluster [Dy(HL)(OAc)(O)(OH)(HO)]·6HO·6CHOH·7CHCN (Dy) by using a multidentate chelate-coordinated diacylhydrazone ligand. Two Dy cages are included in the Dy structure, which are connected via an OAc moiety. The core of Dy is composed of 8 triangular Dy and 12-fold linear Dy units. We further change the alkali added in the reaction system and successfully obtain a single cage-shaped cluster [Dy(HL)(OAc)(OH)(HO)]·2OH·10HO·12CHOH·13CHCN (Dy) with a perfect spherical cavity, which could be considered an intermediate in Dy formation. Time-dependent, high-resolution electrospray ionization mass spectrometry (HRESI-MS) is used to track the formation of Dy. A possible self-assembly mechanism is proposed. We track the formation of Dy and the six intermediate fragments are screened.