Enclosing classical polyoxometallates in silver nanoclusters

Abstract

Due to the elusive nature of polyoxometallates (POMs) in the assembly of silver clusters, POMs trapped by silver clusters are usually different from the pristine form, which surely increases the novelty of the assembly results but makes the final structure predictability challenging. Herein, three novel high-nuclearity silver-thiolate clusters trapping two kinds of classical POMs, Lindqvist-Mo₆O₁₉²⁻ and V₁₀O₂₈⁶⁻, are reported. They are identified to be [(V₁₀O₂₈)@Ag₄₄] (SD/Ag44a), [(V₁₀O₂₈)@Ag₄₆] (SD/Ag46), and [(Mo₆O₁₉)@Ag₄₄] (SD/Ag44b) clusters, which are further extended to 1D chain, 2D sql layer, and 3D pcu framework, respectively. Of note, SD/Ag44b contains a regular cubic Mo₆O₁₉ core sealed by an Ag₄₄(EtS)₂₄ shell in a pseudo-sodalite unit and six SCl₄ planar squares connecting the respective adjacent silver tetragonal faces. This structure is a novel zeolite closely related to the natural alumino-silicate ‘sodalite’ but exceptionally made of core–shell silver clusters. Moreover, the O_h symmetric Mo₆O₁₉²⁻ templates an O_h symmetric Ag₄₄ cluster in SD/Ag44b, realizing authentic symmetry delivery from guest to host in this system. This is a rare silver cluster family with classical POMs encapsulated.