Record High‐Nuclearity Polyoxoniobates: Discrete Nanoclusters {Nb₁₁₄}, {Nb₈₁}, and {Nb₅₂}, and Extended Frameworks Based on {Cu₃Nb₇₈} and {Cu₄Nb₇₈}

Abstract

A series containing the highest nuclearity polyoxoniobate (PONb) nanoclusters, ranging from dimers to tetramers, has been obtained. They include one 114-nuclear {Li₈ ⊂Nb₁₁₄ O₃₁₆ }, one 81-nuclear {Li₃ K⊂Nb₈₁ O₂₂₅ }, and one 52-nuclear {H₄ Nb₅₂ O₁₅₀ }. The Nb nuclearity of these PONbs is remarkably larger than those of all known high-nuclearity PONbs (≤32). Furthermore, the introduction of 3d Cu²⁺ ions can lead to the generation of extended inorganic-organic hybrid frameworks built from novel, high-nuclearity, nanoscale heterometallic PONb building blocks {H₃ Cu₃ Nb₇₈ O₂₂₂ } or {H₃ Cu₄ (en)Nb₇₈ O₂₂₂ }. These building blocks also contain the largest number of Nb centers of any heterometallic PONbs reported to date. The synthesis of new-type PONbs has long been a challenging subject in PONb chemistry.