A series containing the highest nuclearity polyoxoniobate (PONb) nanoclusters, ranging from dimers to tetramers, has been obtained. They include one 114-nuclear {Li ⊂Nb O }, one 81-nuclear {Li K⊂Nb O }, and one 52-nuclear {H Nb O }. The Nb nuclearity of these PONbs is remarkably larger than those of all known high-nuclearity PONbs (≤32). Furthermore, the introduction of 3d Cu ions can lead to the generation of extended inorganic-organic hybrid frameworks built from novel, high-nuclearity, nanoscale heterometallic PONb building blocks {H Cu Nb O } or {H Cu (en)Nb O }. 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.

A protein-sized (ca. 4.2×4.2×3.6 nm ) non-biologically derived molecule {Nb O (OH) (CO ) } (Nb ) containing up to 288 niobium atoms has been obtained, which is by far the largest and the highest nuclearity polyoxoniobate (PONb). Particularly, in terms of metal nuclearity number, Nb is the second largest cluster so far reported in classic polyoxometalate chemistry (V, Mo, W, Nb, and Ta). Nb can be described as a giant windmill-like cluster aggregate of six nanoscale high-nuclearity PONb units {Nb O (OH) (CO ) } (Nb ) joined together by six additional Nb ions. Interestingly, the 47-nuclearity Nb units generated in situ can be isolated and bridged by copper complexes to form an inorganic-organic hybrid three-dimensional PONb framework, which exhibits effective catalytic activity for hydrolyzing nerve agent simulant of dimethyl methylphosphonate. The unique Nb cluster also provides a new type of topology to very limited family of Nb-O clusters.

Four seven-nuclearity 3d-4f heterometallic cluster {FeLnO} substituted polyoxometalates (HPz)KFeLn(μ-O)(B-α-GeWO)(GeWO)· xHO (1-Ln, Pz = piperazine, Ln = Tb, Dy, Ho, Er for x = 27, 25, 25, 24, respectively) have been hydrothermally prepared and structurally characterized by single-crystal X-ray diffraction, powder X-ray diffraction, infrared spectrometry, thermogravimetric analyses, elemental analyses, and electrospray ionization mass spectrometry. Single-crystal X-ray diffraction analyses revealed that 1-Ln contain an unprecedented banana-shaped polyanion constructed from an iron-lanthanide heterometallic {FeLnO} cluster, two trilacunary {B-α-GeWO} units, and one hexalacunary {GeWO} fragment. The magnetic susceptibility surveying proved the presence of antiferromagnetic coupling in 1-Ln.

A rare and novel Cr-substituted polyoxoniobate (PONb), [Cr2.5Nb27.5O66(OH)20(H2O)2]7–, has been synthesized by a combination of hydrothermal and conventional solution methods. The PONb shows an unknown tetrameric structure, which is the largest Cr-containing PONb to date. Interestingly, every two PONb tetramers can be joined together by alkali-metal cations to form a discrete cubelike ionic cluster. The obtained PONb not only enriches the very limited members of the Cr-substituted PONb family but also exhibits high ionic conductivity.

Two new extended polyoxometalate (POM) architectures based on lanthanide-incorporated polyoxoniobate (Ln-incorporated PONb) cages, namely, H4[CuII(en)2]4{K4(H2O)2­[CuII(en)2]5[CuII 5­​(trz)2(en)4(OH)2]­[Dy2CuII 2­(en)2(CO3)3­(H2O)2(OH)3]­[Dy­(H2O)4]­[Dy­Nb23O68­(H2O)4]2}·60H2O (1, en = ethylenediamine) and H20[CuII(en)2]4­{[CuII(en)2]4­[Dy2(C2O4)­(H2O)4]2­[(Nb32(OH)4­(H2O)3­O89]2}·54H2O (2), have been successfully synthesized and structurally characterized, demonstrating a feasible strategy to develop functional POM materials. In addition, the proton conductivity and magnetic behaviors of both 1 and 2 were studied.

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Two inorganic-organic hybrid isopolyoxoniobates (1 and 2) based on new high-nuclearity {Nb54O151} clusters have been synthesized under hydrothermal conditions. Particularly, the combination of the unique {Nb54O151} clusters with copper-amine complexes...

Aprotein-sized (ca. 4.2 4.2 3.6 nm 3 )non-biologically derived molecule {Nb 288 O 768 (OH) 48 (CO 3 ) 12 }( Nb 288 ) containing up to 288 niobium atoms has been obtained, which is by far the largest and the highest nuclearity polyoxoniobate (PONb). Particularly,i nt erms of metal nuclearity number, Nb 288 is the second largest cluster so far reported in classic polyoxometalate chemistry (V,M o, W, Nb, and Ta). Nb 288 can be described as agiant windmill-like cluster aggregate of six nanoscale high-nuclearity PONb units {Nb 47 O 128 (OH) 6 (CO 3 ) 2 }( Nb 47 )j oined together by six additional Nb ions.I nterestingly,t he 47-nuclearity Nb 47 units generated in situ can be isolated and bridged by copper complexes to form an inorganic-organic hybrid three-dimensional PONb framework, which exhibits effective catalytic activity for hydrolyzing nerve agent simulant of dimethyl methylphosphonate.T he unique Nb 47 cluster also provides anew type of topology to very limited family of Nb-O clusters.