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Abstract: A series of new polyoxometalates based on [Ni6(μ3-OH)3(H2O)6(en)3(B-α-PW9O34)] (en=ethylenediamine) clusters capped by different tripodal alcohol ligands have been hydrothermally synthesized and characterized by IR, TGA and single-crystal X-ray diffraction, respectively. The experimental results indicate that the tripodal alcohol ligands can substitute three hydroxyl groups located on the axial positions of the Ni6 cluster to form new polyoxometalates with different substituted modes. [Copyright &y& Elsevier]

Abstract: Two di-cadmium-substituted vanadoarsenates, [Cd(enMe)3]2{α-[(enMe)2Cd2As8V12O40(0.5H2O)]}·5.5H2O (1, enMe=1,2-diaminopropane) and [Cd(enMe)2]2{β-[(enMe)2Cd2As8V12O40(0.5H2O)]} (2), were hydrothermally synthesized and characterized by elemental analyses, IR, TGA, UV–Vis, XRD, magnetic measurements and single crystal structural analyses. Crystal data for 1: monoclinic, P2(1)/c, a=15.040(9)Å, b=20.288(12)Å, c=27.873(17)Å, β=98.046(8)°, V=8421.3(19)Å3, Z=4; for 2: monoclinic, P2(1)/n, a=12.753(3)Å, b=19.334(5)Å, c=14.310(3)Å, β=99.984(3)°, V=3475.1(14)Å3, Z=2. X-ray diffraction analyses reveal that compounds 1 and 2 exhibit isolated and one-dimensional inorganic–organic hybrid structures, respectively. The former is the first di-cadmium-substituted vanadoarsenate derived from α-{As8V14O42} shell, while the latter is another kind of di-cadmium-substituted vanadoarsenate derived from β-{As8V14O42} shell. Variable temperature susceptibility measurements demonstrate the presence of antiferromagnetic interactions between VIV cations in 1 and 2. [Copyright &y& Elsevier]

Abstract: Two new Dawson-based phosphotungstates (H2en)0.5H[Cu(en)2(H2O)]2{[Cu(en)2](α 1-P2W17CuO61)}·8H2O (1) (en=ethylenediamine) and [4,4′-H2bpy]2{[Cu(4,4′-bpy)3][Cu(4,4′-bpy)4(H2O)2]2[Cu(4,4′-bpy)][α-P2W18O62]2}·6H2O (2) (4,4′-bpy=4,4′-bipyridine) have been hydrothermally synthesized and structurally characterized. 1 crystallizes in the triclinic space group P−1 with a=11.7626(17), b=13.246(2), c=29.350(5)Å, α=87.355(5), β=79.583(5), γ=66.993(3)°, V=4138.3(11)Å3, Z=2, GOF=1.089, R 1=0.0563 and wR 2=0.1505, whereas 2 belongs to the orthorhombic space group Iba2 with a=22.277(8), b=47.04(2), c=22.153(8)Å, V=23215(17)Å3, Z=4, GOF=1.051, R 1=0.0627 and wR 2=0.1477. 1 consists of a 1-D linear chain structure constructed from monocopperII-substituted Dawson polyoxoanions, while 2 represents the first 2-D sheet-like structure with a (4,4)-connected topological net built up from plenary Dawson-type polyoxoanions and CuII-4,4′-bpy complex cations in polyoxometalate chemistry. [Copyright &y& Elsevier]

Abstract: Three inorganic–organic composite sandwich-type phosphotungstates [Ni(tepa)(H2O)]4H2[Ni4(H2O)2(α-B-PW9O34)2]·8H2O (1), (enH2)3[Ni2(H2O)10][Ni4(H2O)2(α-B-PW9O34)2]·en·8H2O (2) and (enH2)10[Mn4(H2O)2(α-B-PW9O34)2]2·20H2O (3) (tepa=tetraethylenepentamine and en=ethylenediamine) have been synthesized by the hydrothermal reaction of the trivacant Keggin polyoxoanion [α-A-PW9O34]9− with Ni2+ or Mn2+ ions in the presence of tepa or en and structurally characterized by IR spectra, elemental analysis, thermogravimetric analysis and variable temperature magnetic susceptibility. X-ray crystallographic analyses indicate that they all contain the classical tetra-M sandwiched polyoxoanions [M 4(H2O)2(α-B-PW9O34)2]10− (M=Ni2+ or Mn2+) and nickel-organoamine cations or organoamine cations work as the charge balance ions. The tetra-M clusters in 1, 2 and 3 exhibit the familiar structural type of a β-junction at the sites of metal incorporation. The study of magnetic property of 1 is indicative of a typical ferromagnetic coupling between Ni2+ cations. [Copyright &y& Elsevier]

• The recent advancements of all-inorganic POM cages, including their assembly methodologies, classification and related applications are summarized. • The advantages of using POM clusters as SBUs to construct all-inorganic POM cages are summarized. • Feasible synthetic strategies for further development of all-inorganic POM cages are presented. • Understanding the structure–property/application relationships of all-inorganic POM cages. • The current challenges in the design and fabrication of all-inorganic POM cages as well as the great potential in this area are discussed. Searching for suitable methods to construct all-inorganic cage materials by using polyoxometalates (POMs) as secondary building units (SBUs) has been of great interest, because such materials not only exhibit fascinating cage-shaped structures and unique physicochemical properties derived from both cage architectures and POM clusters, but also have promising and practical applications in areas of molecule separation, guest recognition, molecular reactors, photocatalysis, environmental protection, and so on. In this review, the recent development in all-inorganic POM-based cage materials is summarized, including their assembly methods, structures, properties, and related applications. Moreover, the current challenges in the design and assembly of all-inorganic POM cages as well as the development potential of this area also discussed. [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]

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]

Two new inorganic frameworks HLa(H 2 O)5[La(H 2 O)6]2[La(H 2 O)2(GeW11O39)]2·7H 2 O ( 1 ) and HK(H 2 O)La 3 (H 2 O) 15 [La(H 2 O) 3 (GeW 11 O 39 )] 2 ·38H 2 O ( 2 ) based on 1:1 type lanthanide-substituted polyoxometalates (LSPs) have been synthesized under hydrothermal reactions. Compounds 1 and 2 are characterized by single-crystal X-ray diffraction analysis, thermogravimetry analysis, infrared spectroscopy and X-ray powder diffraction analysis. Interestingly, Compounds 1 and 2 can be selectively obtained by simply controlling the reaction temperatures under similar conditions. Both 1 and 2 are three-dimensional structures built from lanthanide-substituted polyoxoanions [La(H 2 O) n (GeW 11 O 39 )] 5 − building blocks. Furthermore, the ion-conducting properties of 1 and 2 were investigated. [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]

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]

Three novel polyoxometalates (POMs) containing [Ni6(μ3-OH)3]9− and [P2W15O56]12− units were first made, showing the first hexa-nuclearity transition-metal substituted POMs (TMSPs) based on monomeric lacunary Dawson fragments, which further indicates that the hydrothermal technique can offer an effective way for making new TMSPs through lacunary POM fragments incorporated with high-nuclear TM clusters. [ABSTRACT FROM AUTHOR]

[Display omitted] • The developments of POM-templated silver clusters are reviewed. • The syntheses, structures, properties and applications of POM-templated silver clusters are summarized. • The structure–property/application relationships of POM-templated silver clusters are discussed. • The development prospects and the current challenges for POM-templated silver clusters are discussed. • The suggestions for the further development of POM-templated silver clusters are presented. The search for feasible strategies to construct high-nuclear silver clusters has been attracting continuous interests because such materials not only exhibit aesthetic structures and fascinating properties, but also show promising applications in photoluminescence, antibiosis materials, photochromism, nano-materials, and electron transfer/communication materials. Anions are well-known as templates to direct the formation of silver clusters and control the shapes, sizes, and functions of the final products. As a unique class of anionic metal-oxo species, polyoxometalates (POMs) have been widely employed as templates in the syntheses of many intriguing silver clusters. In this review, the advances in POM-templated high-nuclear silver clusters in the past decade are summarized. Additionally, the different templating effects between POMs and simple inorganic anions are discussed. Actually, POMs can do much more than templates for the formation of diverse high-nuclear silver architectures, they also are significant in stabilizing the final products, functionalizing the composite clusters, and so on. Based on the current development in this area, the present challenges and perspectives for such materials are also presented. We hope that this review will be of reference value to accelerate the further development of silver clusters. [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]

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]

Two novel inorganic–organic hybrid 3D TM–Ln incorporated POM-based frameworks, H2[Cu2OL3(H2O)2][Ce(L)(H2O)3(PW11O39)]·17H2O (1) and H4[CuL3]2[Ln(H2O)3(PW11O39)]2·28H2O (2) (L = 4,4′-bipyridine), were hydrothermally synthesized at different temperatures. Structural analysis reveals that both compounds are constructed from [Ln(PW11O39)]4− polyoxoanions and different copper complexes. Interestingly, in compound 1, 2D copper complex layers and 1D chain [Ln(PW11O39)]4− polyoxoanions interconnect to form a 3D framework. In contrast, in compound 2, 1D copper complex chains join the 2D [Ln(PW11O39)]4− layers to give rise to a 3D framework. Both compounds exhibit excellent chemical stability. Furthermore, the dye adsorption and proton conduction properties of both compounds were also investigated. The conductivities of 1 and 2 are 3.175 × 10−4 S cm−1 and 1.750 × 10−4 S cm−1 at 85 °C and 98% RH, respectively. Dye adsorption studies indicate that they can selectively adsorb cationic dyes MB, CV and BR over anionic dyes MO, AO and large cationic RhB. [ABSTRACT FROM AUTHOR]

[Display omitted] • The developments of all-inorganic POM-based frameworks including their syntheses, structures, properties and related applications are summarized. • The structure–property/application relationships of all-inorganic POM-based frameworks are summarized. • Feasible synthetic strategies for further development of all-inorganic POM-based frameworks are presented. • The development prospects and the current challenges for all-inorganic POM-based frameworks are discussed. Polyoxometalates (POMs) are an intriguing class of compounds that have been extensively studied due to their unique structures and diverse properties. In the past years, the synthesis of POM-based all-inorganic open frameworks has attracted increasing attention due to their potential applications in various fields, such as in electrode, magnetic, and catalytic materials. This review not only provides a comprehensive survey on POM-based all-inorganic open frameworks, including their structures, properties, and potential applications, but also discusses the current challenges in this field and provides an outlook for future research directions. [ABSTRACT FROM AUTHOR]

A tin(ii) tungstosilicate derivative K11H[Sn4(SiW9O34)2]·25H2O with four sandwiched Sn2+cations was prepared by reaction of SnCl2, KCl and Na10[α-SiW9O34]·xH2O. Visible-light photocatalytic H2evolution activity was observed with Pt nanoparticles as co-catalyst and methanol as sacrificial agent. [ABSTRACT FROM AUTHOR]

A series of new Ln14-substituted polyoxometalates, H27Na16[(Ln14(H2O)W4(OH)O14)(WO4)4(GeW10O38)6]·nH2O (n≈ 86) (1-Ln, Ln = Eu, Gd, Tb, Dy, Ho, Er), which contain 14 Ln3+ and 6 {α(1,5)-[GeW10O38]12−} units, has been synthesized in one-pot reactions. As the first 14-Ln-containing polyoxometalates, the octahedron-shaped three-shell structure of the [(Ln14(H2O)W4(OH)O14)(WO4)4(GeW10O38)6]43− polyanion is made up of a W4 tetrahedron, a Ln14W4 tetrahedron and a Ge6W60 octahedron. Compound 1-Dy exhibits frequency dependent magnetic properties. Compounds 1-Eu, 1-Tb and 1-Dy exhibit the characteristic emission bands of the Ln3+ ion. [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]

Two rare mixed-cluster-organic frameworks (CH3NH3)3[Cu4-(μ3-O)2(Lb)4][MnMo6O18(La)2]·4NMF·5H2O (1) and [(CH3)2NH2]3[Co5-(μ3-O)2(Lb)6]-[MnMo6O18(La)2]·5DMF (2) (La = 2-(hydroxymethyl)-2-(pyridin-4-yl)-1,3-propanediol; Lb = 4-(2-(4-pyridyl)ethenyl) benzoic acid; NMF = N-methylformamide; DMF = N,N-dimethylformamide) have been obtained, exhibiting the first two porous materials simultaneously integrating polyoxometalates and transition-metal–oxygen clusters as secondary building units (SBUs). [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]

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. [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]

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]

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]

The first two tetra-Sc-substituted polyoxotungstates H 2 K 2 Na 2 [Sc 4 (H 2 O) 10 ( B -β-SbW 9 O 33 ) 2 ]·21H 2 O (1) and H 20 K 2 Na 6 [Sc 4 (C 2 O 4 ) 4 ( B -β-SbW 9 O 33 ) 2 ][Sc 4 (H 2 O) 2 (C 2 O 4 ) 4 ( B -β-SbW 9 O 33 ) 2 ]·64H 2 O (2) have been synthesized and characterized by IR spectroscopy, AC impedance measurements, TG, PXRD, and single-crystal X-ray diffractions. Compound 1 represents an isolated inorganic sandwich-type dimeric POM constructed from two trilacunary Keggin [ B -β-SbW 9 O 33 ] 9 − moieties and four Sc 3 + ions, while compound 2 shows an extended organic–inorganic hybrid POM which composes of two kinds of distinct tetra-Sc-substituted polyoxotungstate building units and oxalate ligands. Notably, these two compounds also are the first Sc-containing polyoxotungstates based on trilacunary Keggin [ B -β-SbW 9 O 33 ] 9 − clusters. Electrochemical study showed that compound 2 has good proton conductivity. [ABSTRACT FROM AUTHOR]

Polyoxoniobate [GeNb 18 O 54 ] 14 − and polyniobotungstate [Nb 3 W 3 O 19 ] 5 − are firstly found to co-crystallize at the same crystal to form a rare organic–inorganic hybrid polyoxometalate H[Cu(en) 2 (H 2 O)] 8 [Cu(en) 2 (H 2 O) 2 ] 2 {K 4 [Cu(en) 2 ] 2 [Cu(en) 2 (GeNb 18 O 54 )] 2 }[Nb 3 W 3 O 19 ]·32H 2 O ( 1 ). Interestingly, in 1 , the crescent-shaped polyoxoanions [GeNb 18 O 54 ] 14 − can form dimeric secondary building units (SBUs) {[GeNb 18 O 54 ] 2 [K 2 (H 2 O) 5 ] 2 } via the linkage of K + cations. These dimeric SBUs can be further bridged by copper complexes to generate 1D infinite double strand chains with completely different isolated polyoxoanions [Nb 3 W 3 O 19 ] 5 − filling the gaps between chains. [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]

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]

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]

Four tetra-Cd-substituted vanadogermanates (V-Ge-Os) H 2 [Cd(dap) 2 {[Cd(dap)] 4 [Ge 8 V 10 O 38 (OH) 8 }·10H 2 O (1), H[Cd(phen)(H 2 O) 2 2 {[Cd(phen)] 4 Ge 8 V 10 O 39 (OH) 7 }·2H 2 O (2), [Cd(phen) 2 2 {[Cd(phen)] 2 [Cd(dap)] 2 Ge 8 V 10 O 38 (OH) 8 }·2H 2 O (3) and H 2 [Cd(phen) 2 4 {[Cd(phen)] 4 [Ge 8 V 10 O 40 (OH) 6 }{[Cd(phen)] 2 [Cd(H 2 O) 2 2 [Ge 8 V 10 O 38 (OH) 8 }·10H 2 O (4) (dap ​= ​1,2 - diaminopropane; phen ​= ​1,10 - phenanthrolinemonohydrate) have been hydrothermally prepared and structurally characterized. Single crystal X-ray structural analyses indicate that all of 1 – 4 contain uncommon tetra-Cd-substituted V-Ge-O clusters. 1 is a rare one-dimensional chain based on tetra-Cd-substituted V-Ge-O clusters, while 2–4 are unique discrete tetra-Cd-substituted V-Ge-O clusters decorated with different metal-organoamine complexes. Furthermore, the thermal/chemical stability of 1 and 2 as well as the magnetic properties of 1 , 2 and 4 were investigated. In this work, four tetra-Cd-substituted vanadogermanates was successfully prepared and characterized. The tetra-Cd-substituted vanadogermanate cluster is a flexible unit, which can be not only decorated by various transition-metal complexes to form different isolated structures, but also bridged by transition-metal complexes to generate an extended 1-dimensional chain. Image 1 • Four unique tetra-Cd-substituted vanadogermanates have been hydrothermally made. • Compound 1–4 represent the second series of tetra-Cd-substituted V-Ge-Os. • Compound 1 is a novel 1-dimensional chain based on tetra-Cd-substituted V-Ge-O cluster. • Compound 3 is an uncommon tetra-Cd-substituted V-Ge-O containing mixed chelating organoamine ligands. • Compound 4 is the first V-Ge-O containing two electrically different tetra-Cd-substituted V-Ge-O clusters in one structure. [ABSTRACT FROM AUTHOR]

A series of novel 4s–4f heterometallic cluster substituted polyoxometalates (POMs) with formula of H 9 Na 12 K 2 [K 3 Ln 4 (NO 3) 2 (GeW 10 O 37) 2 (Ge 2 W 18 O 66)]·34H 2 O (1-Ln) (Ln = Dy, Ho, Er) have been hydrothermally made by adopting a trilacunary [A-α-GeW 9 O 34 ]10− as a precursor. 1-Ln represent the first examples of metal-substituted POM clusters based on mixed POM fragments including dilacunary [α-GeW 10 O 37 ]10− and multilacunary open Well-Dawson [Ge 2 W 18 O 66 ]16− fragments. • Novel 4s–4f heterometallic substituted POMs have been prepared and characterized. • The compounds contain mixed Keggin/ open Well-Dawson POM fragments. • The Luminescent properties of these compounds were systematically studied. • The work enriches the diversity of heterometallic metal cluster substituted POMs. • This work provides a new route for making new POMs based on mixed POM units. By adopting a trilacunary [A-α-GeW 9 O 34 ]10− as a precursor under hydrothermal conditions, a series of novel 4s–4f cluster substituted polyoxometalates (POMs) containing two types of in situ generated lacunary POM fragments have been made. These compounds were characterized by single-crystal X-ray diffractions, powder X-ray diffractions, infrared spectroscopy, thermogravimetric analyses, respectively. Structural analyses indicate that these compounds constructed from a seven-nuclearity K-O-Ln (Ln = Dy, Ho, Er) heterometallic cluster stabilized by mixed dilacunary Keggin [α-GeW 10 O 37 ]10−/multilacunary open Wells-Dawson [Ge 2 W 18 O 66 ]16− fragments. Furthermore, the solid luminescent properties of the compounds at room temperature were studied. [ABSTRACT FROM AUTHOR]

A series of Nb-W-Ln heterometallic polyoxometalates {Ln12W12O36(H2O)24 (Nb6O19)12} (Ln: Y, La, Sm, Eu, Yb) is prepared by e.g. hydrothermal reaction of K7HNb6O19, Na2WO4, Cu(OAc)2, SmCl3, trimesic acid, and en in a carbonate buffer at pH 10.5 (autoclave, 160 °C, 72 h, 70% yield). [ABSTRACT FROM AUTHOR]