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Atomically precise low‐nuclearity (n<10) silver nanoclusters (AgNCs) have garnered significant interest due to their size‐dependent optical properties and diverse applications. However, their synthesis has remained challenging, primarily due to their inherent instability. The present study introduces a new feasible approach for clustering silver ions utilizing highly negative and redox‐inert polyoxoniobates (PONbs) as all‐inorganic ligands. This strategy not only enables the creation of novel Ag‐PONb composite nanoclusters but also facilitates the synthesis of stable low‐nuclearity AgNCs. Using this method, we have successfully synthesized a small octanuclear rhombic [Ag8]6+ AgNC stabilized by six highly negative [LiNb27O75]14− polyoxoanions. This marks the first PONb‐protected superatomic AgNC, designated as {Ag8@(LiNb27O75)6} (Ag8@Nb162), with an aesthetically spherical core–shell structure. The crystalline Ag8@Nb162 is stable under ambient conditions, What's more, it is water‐soluble and able to maintain its molecular cluster structure intact in water. Further, the stable small [Ag8]6+ AgNC has interesting temperature‐ and pH‐dependent reversible fluorescence response, based on which a multiple optical encryption mode for anti‐counterfeit technology was demonstrated. This work offers a promising avenue for the synthesis of fascinating and stable PONb‐protected AgNCs and sheds light on the development of new‐type optical functional materials. [ABSTRACT FROM AUTHOR]

Inspired by the metal‐oxo cluster structural feature and charge separation behaviour of the oxygen evolving center (OEC) in photosystem II (PS‐II) under photoirradiation, a new crystalline photochromic polyoxomolybdate, MV2[β‐Mo8O26] (1, MV=methyl viologen cation), is designed as a biomimetic oxygen evolution reaction (OER) catalyst in neutral electrolytes. After photoinduced electron transfer (PIET) with colour change from colourless to grey, it remains in an ultra‐stable charge‐separated state over a year under ambient conditions. The observed overpotential at 10 mA ⋅ cm−2 and Tafel slope decrease by 49 mV and 62.8 mV ⋅ dec−1 after coloration, respectively. The outstanding OER performance of the coloured state in neutral electrolytes even outperforms the commercial RuO2 benchmark. Experimental and theoretical studies show that oxygen holes within polyanions after irradiation serve as sites for enhancing direct O−O coupling, thus effectively promoting OER. This is the first successful application of electron‐transfer photochromism to realize OER activity gain. [ABSTRACT FROM AUTHOR]

Only rarely have polyoxometalates been found to form core–shell nanoclusters. Here, we succeeded in isolating a series of rare giant and all‐inorganic core–shell cobalt polyoxoniobates (Co−PONbs) with diverse shapes, nuclearities and original topologies, including 50‐nuclearity {Co12Nb38O132}, 54‐nuclearity {Co20Nb34O128}, 62‐nuclearity {Co26Nb36O140} and 87‐nuclearity {Co33Nb54O188}. They are the largest Co−PONbs and also the polyoxometalates containing the greatest number of Co ions and the largest cobalt clusters known thus far. These molecular Co−PONbs have intriguing and atomically precise core–shell architectures comprising unique cobalt oxide cores and niobate oxide shells. In particular, the encapsulated cobalt oxide cores with different nuclearities have identical compositions, structures and mixed‐valence Co3+/Co2+ states as the different sized Co−O moieties of the bulk cubic‐spinel Co3O4, suggesting that they can serve as various molecular models of the cubic‐spinel Co3O4. The successful construction of the series of the Co−PONbs reveals a feasible and versatile synthetic method for making rare core–shell heterometallic PONbs. Further, these new‐type core–shell bimetal species are promising cluster molecular catalysts for visible‐light‐driven CO2 reduction. [ABSTRACT FROM AUTHOR]

Compounds with redox activities have appealing applications in catalytic, electronic and magnetic properties, but the redox inert of polyoxoniobates (PONbs) significantly limits their applications for a long time. In this work, we are able to integrate organophosphate and lanthanide cluster into PONb to create the first family of inorganic‐organic hybrid organophosphate‐Ln‐PONb composite clusters. These novel species not only present the first family of redox active PONbs that can be reduced to form long‐lived "heteropoly blues" under ambient conditions, but also a new photochromic system. More importantly, the analyses of the electronic configurations and photochromic properties for a series of designed proof‐of‐concept PONbs models allow us to discover a D‐f‐A electron transfer mechanism, that is, photoinduced electron is transferred from a photosensitive organophosphate electron donor (D) to the NbV electron acceptor (A) through the unoccupied 4 f‐orbitals of Ln (f). This work paves the way for developing diverse PONb‐based redox materials and expanding the possibility of the applications of PONbs in the redox chemistry. [ABSTRACT FROM AUTHOR]

This work reports the interesting and unique cation‐exchange behaviors of the first indium‐bridged purely inorganic 3D framework based on high‐nuclearity polyoxoniobates as building units. Each nanoscale polyoxoniobate features a fascinating near‐icosahedral core–shell structure with six pairs of unique inorganic "molecular tweezers" that have changeable openings for binding different metal cations via ion‐exchanges and exhibit unusual selective metal‐uptake behaviors. Further, the material has high chemical stability so that can undergo single‐crystal‐to‐single‐crystal metal‐exchange processes to produce a dozen new crystals with high crystallinity. Based on these crystals and time‐dependent metal‐exchange experiments, we can visually reveal the detailed metal‐exchange interactions and mechanisms of the material at the atomic precision level. This work demonstrates a rare systematic and atomic‐level study on the ion‐exchange properties of nanoclusters, which is of significance for the exploration of cluster‐based ion‐exchange materials that are still to be developed. [ABSTRACT FROM AUTHOR]

Herein, a giant Sb‐rich polyoxometalate (POM) {Sb21Tb7W56} is reported, which contains the largest number of Sb atoms in a POM so far. The Sb‐rich POM has many interesting structural features and is a rare example of a soluble and water‐stable giant POM. Biomedical studies indicate that the Sb‐rich POM exhibits broad‐spectrum antitumor activity against various cancer cell lines by reactivating the P53‐dependent apoptotic processes and disrupting the mitochondrial membrane. In addition, this Sb‐rich POM was capable of suppressing the growth and metastasis of a breast cancer in vivo. This work demonstrates that Sb‐rich POMs are promising candidates for the development of new anticancer drugs. [ABSTRACT FROM AUTHOR]

Cup‐shaped molecules are of great interest due to their appealing architectures and properties. Compared with widely studied calixarenes, polyoxometalate‐based cup‐shaped molecules currently remain a virgin land waiting for exploration. In this work, we report the first discovery of two giant cup‐shaped inorganic–organic hybrid polyoxoniobates (PONbs) of {Cu12Nb120} and {Cd16Nb128}. The former integrates three tricyclic Nb24 clusters and a hexacyclic Nb48 cluster into a cup‐shaped molecule via a Cu12 metallacalixarene, while the latter unifies two tricyclic Nb24 clusters and a brand‐new pentacyclic Nb40 cluster into another cup‐shaped molecule via a hybrid Cd16 unit. With 132 and 144 metal centers, {Cu12Nb120} and {Cd16Nb128} show the largest two inorganic–organic hybrid PONbs known to date. [ABSTRACT FROM AUTHOR]

The development of new‐type memristors with special performance is of great interest. Herein, an inorganic‐organic hybrid crystalline polyoxometalate (POM) with usual dynamic structures is reported and used as active material for fabricating memristor with unique temperature‐regulated resistive switching behaviors. The hybrid POM not only exhibits tunable thermochromic properties, but also thermal‐induced reversible aggregation and disaggregation reactions, leading to reversible structural transformations in SCSC fashion. Further, the memory device using the hybrid POM as active layer exhibits uncommon performance, which can keep resistive switching silent in the low temperature range of 30–150 °C, but show nonvolatile memory behavior in the high temperature range of 150–270 °C. Particularly, the silent and working states at three special temperatures (30, 150 and 270 °C) can be monitored by chromism. The correlation between structure and resistive switching property of the material has been discussed. The work demonstrates that crystalline inorganic‐organic hybrid POMs are promising materials for making memristors with superior performance. [ABSTRACT FROM AUTHOR]

A Sb‐embedded polyoxoniobate has been originally synthesized under hydrothermal conditions. Particularly, the peanut‐like [Sb2Nb24O72]18− cluster cage in 1 with C2h symmetry is composed of two 9‐nuclear {SbNb9O33} motifs and one {Nb6O24} crown‐shaped ring. The compound 1 present the novel structure of Sb‐substituted sandwich‐type polyoxoniobate with antimoniobate cluster cage. Decomposition catalytic studies indicate that compound 1 exhibits good hydrolytic activity and stability on the degradation of nerve agent simulant dimethylphosphonate (DMMP). [ABSTRACT FROM AUTHOR]

In this work, two rare high‐dimensional polyoxoniobates with formulas of H9[Cu(en)(H2O)2][Cu(en)2]8[Dy(H2O)4]3[Nb24‐O69(H2O)3]2 ⋅ 36H2O (1) and H9K[Cu(en)2(H2O)]5[Cu(en)2]4‐[Eu(H2O)4]3[Nb24O69(H2O)3]2 ⋅ 2en ⋅ 45H2O (2) have been obtained under hydrothermal conditions. These extended materials are constructed from lanthanide‐incorporated triangular‐prism‐like polyoxoniobate secondary building units (SBUs) {[Ln(H2O)4]3[Nb24O69(H2O)3]2} (Ln=Dy, Eu). 1 and 2 represent the first examples of high‐dimensional polyoxometalate materials based on such lanthanide‐incorporated triangular‐prism‐like polyoxoniobate SBUs. Furthermore, the proton conduction property and the luminescent emission of these materials were evaluated. [ABSTRACT FROM AUTHOR]

The combination of polyoxoniobates (PONbs) with 3d metal ions, azoles, and organoamines is a general synthetic procedure for making unprecedented PONb metal complex cage materials, including discrete molecular cages and extended cage frameworks. By this method, the first two PONb metal complex cages K4@{[Cu29(OH)7(H2O)2(en)8(trz)21][Nb24O67(OH)2(H2O)3]4} and [Cu(en)2]@{[Cu2(en)2(trz)2]6(Nb68O188)} have been made. The former exhibits a huge tetrahedral cage with more than 120 metal centers, which is the largest inorganic–organic hybrid PONb known to date. The later shows a large cubic cage, which can act as building blocks for cage‐based extended assembly to form a 3D cage framework {[Cu(en)2]@{[Cu2(trz)2(en)2]6[H10Nb68O188]}}. These materials exhibit visible‐light‐driven photocatalytic H2 evolution activity and high vapor adsorption capacity. The results hold promise for developing both novel cage materials and largely unexplored inorganic–organic hybrid PONb chemistry. [ABSTRACT FROM AUTHOR]

Two unique heterometallic cluster organic frameworks, [Cd4MnIII4MnII6(Tri)4(CH3COO)14(μ4‐O)2(μ3‐O)2(H2O)2] Cd(H2O)2⋅9 H2O (1) and Cu[Cd5Cu6(Tri)4(CH3COO)9(H2O)4]2(CH3COO)3⋅24 H2O (2) (H3Tri=2‐(hydroxymethyl)‐2‐(pyridine‐4‐yl)‐1,3‐propanediol), have been successfully prepared by employing a bifunctional tripodal alcohol ligand as a structure‐directing agent. Crystal structure analyses reveal that 1 represents a rare example of frameworks constructed from Cd−Mn heterometallic chains, and 2 is the first heterometallic MOF based on highest‐nuclear Cd−Cu heterometallic cluster building blocks. Furthermore, the magnetic properties and gas adsorption abilities of 1 and 2 were systematically studied. [ABSTRACT FROM AUTHOR]

In this paper, we report a series of novel mixed‐metal‐substituted organic‐inorganic hybrid polyoxometalates (POMs) H3[(CH3)4N]14[NaLn(PW11O39)3]·18H2O (1‐Ln, Ln = Nd, Sm, Eu) via one‐pot solvothermal synthesis methods, which present the first series of polyoxometalate trimers composed of both alkali‐metal‐ and lanthanide‐substituted keggin‐type POMs. The trimeric heterometallic polyoxoanions in 1‐Ln show an interesting linear arrangement and can be further packed together to generate a packing structure with cations [(CH3)4N]+ and H3O+ filling the gaps between polyoxoanions. Compounds 1‐Ln are characterized by single‐crystal X‐ray diffraction analysis, TGA, IR and PXRD. Additionally, the luminescence and proton conductive properties of 1‐Ln are also characterized. A series of unprecedented linear mixed‐metal‐substituted organic‐inorganic hybrid polyoxometalate trimers H3[(CH3)4N]14[NaLn(PW11O39)3]·18H2O (1‐Ln, Ln = Nd, Sm, Eu), composed of both alkali‐metal‐ and lanthanide‐substituted keggin‐type POMs, show interesting luminescence and proton conductive properties. [ABSTRACT FROM AUTHOR]

During the past decade, research on the design and synthesis of zeolite‐like metal–organic frameworks (ZMOFs) has developed greatly. As an important subclass of ZMOFs, zeolite‐like cluster organic frameworks (ZCOFs) built from 4‐connected metal‐cluster secondary building units (SBUs) and appropriate linear organic ligand bridges have attracted sustained interest, because such materials not only integrate the merits of inorganic zeolites, ZMOFs, and metal clusters, including interesting topologies, high surface areas, extra‐large cavities and channels, structural tunability, and unique physicochemical properties from various metal clusters, but also open up a new avenue to design and fabricate hybrid zeolite‐like materials that have many potential applications in material sciences. In this review, recent developments in ZCOFs are summarized by classifying the ZCOFs into four categories according to the composition of the SBUs: 1) ZCOFs based on metal–halide cluster SBUs, 2) ZCOFs based on metal–oxygen cluster SBUs, 3) ZCOFs based on metal–chalcogen cluster SBUs, and 4) ZCOFs based on mixed types of metal‐cluster SBUs. Besides, challenges associated with the design and synthesis of ZCOFs and the vast potential of this area are also discussed. A frame of reference: Zeolite‐like cluster organic frameworks (ZCOFs) built from 4‐connected metal‐cluster secondary building units (SBUs) have attracted sustained interest due to their charming structures and potential applications in materials sciences. This Minireview presents a summary of recent advances in the development of ZCOF materials. Challenges associated with the design and synthesis of ZCOFs and the vast potential of this area are also discussed. [ABSTRACT FROM AUTHOR]

This work demonstrates that the use of high‐negative and high‐symmetry lacunary polyoxometalates (POMs) for the clustering of alkali metal ions is a feasible strategy not only for the formation of rare high‐nuclearity alkali‐metal clusters but also for the construction of new‐type all‐inorganic ionic porous materials. By the strategy, an unprecedented high‐nuclearity K‐H2O cluster {K42(H2O)60} with core–shell K6@K36 configuration is stabilized by 8 C3v‐symmetry trivacant POMs [GeW9O34]10−, forming a novel giant ionic alkali‐metal‐POM composite cluster {K42Ge8W72O272(H2O)60} with more than 100 metal centers. The incorporated 42‐nuclearity K‐H2O cluster {K42(H2O)60} exhibits the highest‐nuclearity alkali‐metal‐water cluster known to date in POM chemistry. Further, the giant {K42Ge8W72O272(H2O)60} clusters can be linked by another kind of alkali metal ions Na+ to generate a fascinating three‐dimensional all‐inorganic ionic porous framework with high chemical stability, proton conductivity, and water vapor adsorption. Giant ionic cluster: The utilization of highly negative polyoxometalates for the clustering of alkali metal cations has allowed the synthesis of a rare all‐inorganic ionic porous material built from novel giant ionic clusters {K42Ge8W72O272(H2O)60} (K42W72), which exhibits high proton conductivity. The K42W72 not only is among the largest ionic clusters but also contains unprecedented core–shell K6@K36‐H2O cage. [ABSTRACT FROM AUTHOR]

Abstract: A protein‐sized (ca. 4.2×4.2×3.6 nm3) non‐biologically derived molecule {Nb288O768(OH)48(CO3)12} (Nb288) 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, Nb288 is the second largest cluster so far reported in classic polyoxometalate chemistry (V, Mo, W, Nb, and Ta). Nb288 can be described as a giant windmill‐like cluster aggregate of six nanoscale high‐nuclearity PONb units {Nb47O128(OH)6(CO3)2} (Nb47) joined together by six additional Nb ions. Interestingly, the 47‐nuclearity Nb47 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 Nb47 cluster also provides a new type of topology to very limited family of Nb‐O clusters. [ABSTRACT FROM AUTHOR]

Two zeolite-like cluster organic frameworks based on Cd-Cu/Mn-Cu heterometallic supertetrahedral secondary building units have been successfully constructed under solvothermal conditions, namely, Cu[Cd4Cu6(L)4(H2O)18](Ac)9 ⋅DMA ⋅3 H2O ( 1), and Cu[Mn4Cu6(L)4(Ac)3(H2O)12](Ac)6 ⋅CH3CN ⋅13 H2O ( 2), where H3L=2-(hydroxymethyl)-2-(pyridin-4-yl)-1,3-propanediol, Ac=CH3COO−, DMA= N, N′-dimethylacetamide. Single-crystal X-ray structural analysis reveals that both 1 and 2 exhibit 3-dimensional zeolite-like architectures with similar 4-connected components, but possess definitely different topologies of diamondoid (dia) and uncommon lonsdaleite (lon), respectively. 1 and 2 represent the first cases of zeolite-like cluster organic frameworks containing Cd-Cu/Mn-Cu heterometallic supertetrahedral secondary building units. Furthermore, the magnetic properties and porous nature of 1 and 2 were also studied. [ABSTRACT FROM AUTHOR]

A series containing the highest nuclearity polyoxoniobate (PONb) nanoclusters, ranging from dimers to tetramers, has been obtained. They include one 114-nuclear {Li8⊂Nb114O316}, one 81-nuclear {Li3K⊂Nb81O225}, and one 52-nuclear {H4Nb52O150}. 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 {H3Cu3Nb78O222} or {H3Cu4(en)Nb78O222}. 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. [ABSTRACT FROM AUTHOR]

A series containing the highest nuclearity polyoxoniobate (PONb) nanoclusters, ranging from dimers to tetramers, has been obtained. They include one 114-nuclear {Li8⊂Nb114O316}, one 81-nuclear {Li3K⊂Nb81O225}, and one 52-nuclear {H4Nb52O150}. 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 {H3Cu3Nb78O222} or {H3Cu4(en)Nb78O222}. 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. [ABSTRACT FROM AUTHOR]

Four indium-based heterometallic metal-organic frameworks In3M(IMDC)3(NO3)2(H2O)6 ·solvent ( 2-M, M = Mn, Co, Zn, Mg, H3IMDC = imidazole-4,5-dicarboxylic acid) have been made under solvothermal conditions, and are characterized by single-crystal X-ray diffraction studies, energy-dispersive X-ray spectroscopy, infrared spectroscopy, thermogravimetric analysis, and powder X-ray diffraction analysis. Structural analysis indicates that 2-M exhibit 3D porous frameworks generated by linking three intersecting 1D In-IMDC helical chains with different M2+ ions. Powder X-ray diffraction studies reveal that 2-M exhibit good thermal and water stability. Furthermore, 2-M show moderate gas adsorption abilities that can be modulated by introducing different M2+ ions. Finally, the solid-state luminescent emissions of 2-M at room temperature are also elucidated. [ABSTRACT FROM AUTHOR]

A series of polyoxometalates (POMs) that incorporate the highest-nuclearity Ln clusters that have been observed in such structures to date (Ln26 , Ln=La and Ce) are described, which exhibit giant multishell configurations (Ln⊂W6⊂Ln26⊂W100). Their structures are remarkably different from known giant POMs that feature multiple Ln ions. In particular, the incorporated Ln-O clusters with a nuclearity of 26 are significantly larger than known high-nuclearity (≤10) Ln-O clusters in POM chemistry. Furthermore, they also contain the largest number of La and Ce centers for any POM reported to date and represent a new kind of rare giant POMs with more than 100 W atoms. Interestingly, the La26-containing POM can undergo a single-crystal to single-crystal structural transformation in the presence of various transition-metal ions, such as Cu2+, Co2+, and Ni2+, from an inorganic molecular nanocluster into an inorganic-organic hybrid extended framework that is built from POM building blocks with even higher-nuclearity La28 clusters bridged by transition-metal complexes. [ABSTRACT FROM AUTHOR]

The first series of niobium-tungsten-lanthanide (Nb-W-Ln) heterometallic polyoxometalates {Ln12W12O36(H2O)24(Nb6O19)12} (Ln=Y, La, Sm, Eu, Yb) have been obtained, which are comprised of giant cluster-in-cluster-like ({Ln12W12}-in-{Nb72}) structures built from 12 hexaniobate {Nb6O19} clusters gathered together by a rare 24-nuclearity sodalite-type heterometal-oxide cage {Ln12W12O36(H2O)24}. The Nb-W-Ln clusters present the largest multi-metal polyoxoniobates and a series of rare high-nuclearity 4d-5d-4f multicomponent clusters. Furthermore, the giant Nb-W-Ln clusters may be isolated as discrete inorganic alkali salts and can be used as building blocks to form high-dimensional inorganic-organic hybrid frameworks. [ABSTRACT FROM AUTHOR]

A novel discrete neutral Cd17 sulfide cluster (denoted CMM-9) with seven corners has been synthesized by slow diffusion of methanol into a mixed solution (DMF/CS2 = 1:1, weight ratio) containing an ionic starting material CMM-4. The structures of CMM-4 and CMM-9 are determined from single crystal X-ray diffraction data collected at 150 K. The structure of the new Cd17 cluster is distinctly different from the well-known C1 cluster that also has 17 Cd sites. The UV/Vis spectrum of the new cluster CMM-9 revealed a maximum absorption at 305 nm in DMF solution, which is slightly red-shifted compared to the regular C1 cluster (C1, [Cd17S4(SPh)28]2-, with a maximum absorption at 296 nm). [ABSTRACT FROM AUTHOR]

Exploring noble‐metal‐free, highly active and durable catalysts is vital to get to grips with the energy and environmental issues. Herein, we first dexterously design and synthesize a class of ternary Nb6/CZS/g‐CN photocatalysts for the removal of hexavalent chromium Cr (VI) and organic dye pollutant (MO) from wastewater under visible‐light irradiation. A heterojunction Nb6–1/CZS/g‐CN loaded with 0.01 g K7HNb6O19 showed excellent photocatalytic performance, with the MO photodegradation efficiency of 94% in 1 h and the Cr (VI) (150 mg/l) photoreduction efficiency as high as 91% in 2 hr. The main active species were deemed to be O2.‐. Additionally, the as‐prepared ternary heterojunction exhibits superior hydrogen evolution reaction (HER) rate. A heterojunction Nb6–4/CZS/g‐CN loaded with 0.5 g K7HNb6O19 exhibited the highest H2 evolution rate as high as 1777.86 μmol h−1 g−1 under visible‐light illumination, which is increased to 5.7 and 2.7 times that of bare CZS and biphase heterojunction CZS/g‐CN. These findings afford a new class of promising low‐cost photocatalyst bodying for its huge potential value in sustainable energy development and wastewater treatment. [ABSTRACT FROM AUTHOR]