Discovery and Isolation of Two Arsenotungastate Species: [As4W48O168]36- and [As2W21O77(H2O)3]22

Two novel arsenotungstate species, [As₄W₄₈O₁₆₈]^36- (1a) and [As₂W₂₁O₇₇(H₂O)₃]^22- (2a), have been successfully isolated under a one-pot synthetic method. 1a is the second largest arsenotungstate cluster and is constructed from four {AsW₁₂} clusters combined together. 2a can be described as lacunary sites of {As₂W₁₉} filled by {W₂O₈} units. Compounds 1 and 2 exhibit proton conductivity properties, and the conductivity value of 1 is 5.0 × 10^-3 S cm^-1 at 98% relative humidity and 75 °C. This work proves that the lattice water molecules and polyoxoanions can participate in the formation of a hydrogen bond, acting as effective pathway for intermolecular proton conduction.

Series of the Largest Dish-Shaped Dysprosium Nanoclusters Formed by In Situ Reactions

A three-dimensional supermolecule structure is easily formed due to the diverse coordination modes of high-oxidation-state lanthanide metal ions. However, the design and construction of zero-dimensional (0 D) dish-shaped high-nuclearity lanthanide clusters are difficult. Herein, for the first time, we synthesized a series of the largest dish-shaped high-nuclearity lanthanide nanoclusters (1-4) by in situ tandem reactions under solvothermal one-pot conditions. The formation of 1 and 2 involved an in situ reaction of aldehydes and amines, while the condensation reactions between aldehydes occurred in 3 and 4. Based on the structural characteristics of the dish-shaped lanthanide clusters, we proposed two possible assembly mechanisms involving Dy₁ → Dy₇ → Dy₁₃ → Dy₁₉ (planar epitaxial growth mechanism) and Dy₁ → Dy₁₂ → Dy₁₈ → Dy₁₉ (planar internal growth mechanism).

Organic–inorganic hybrids assembled from plenary Keggin-type germanotungstate units and 3d–4f heterometal clusters

Two kinds of 3d–4f heterometal plenary Keggin germanotungstates were prepared. Their electrochemical sensing properties towards Acetaminophen detection were investigated.

Pyrazine dicarboxylate-bridged arsenotungstate: synthesis, characterization, and catalytic activities in epoxidation of olefins and oxidation of alcohols

The catalytic properties and polyanionic structure of pyrazine dicarboxylate-bridged arsenotungstate are reported.

Preparation, characterization, and catalytic performances of a pyrazine dicarboxylate-bridging rare-earth-containing polytungstoarsenate aggregate for selective oxidation of thiophenes and deep desulfurization of model fuels

A new polytungstoarsenate, K₆LiH₆[Ce₄(H₂O)₁₄(pzdc)(H₂pzdc)As₃W₂₉O₁₀₃]·22H₂O (1), was synthesized via a conventional aqueous solution method.

Discovery and isolation of the trans-isomers of two 1 : 2-type lanthanide-containing monolacunary Dawson-type tungstophosphates: [LnIII(α2-P2W17O61)2]17− (Ln = La, Ce)

Two novel trans-isomers of 1 : 2-type lanthanide-containing monolacunary Dawson-type tungstophosphates [Ln(α₂-P₂W₁₇O₆₁)₂]¹⁷⁻ (Ln = La^III (1), Ce^III (2)) were successfully isolated and characterized.

Lanthanoid Template Isolation of the α-1,5 Isomer of Dicobalt(II)-Substituted Keggin Type Phosphotungstates: Syntheses, Characterization, and Magnetic Properties

A new series of heterometallic 3d-4f sandwich type phosphotungstates, [Ln{PCo2W10O38(H2O)2}2](11-) (Ln = Sm(III), Eu(III), Gd(III), Tb(III), Dy(III), Ho(III), Er(III), Tm(III), Yb(III), and Lu(III), denoted 1a-10a, respectively), have been synthesized by a one-pot reaction procedure on reacting the dilacunary K14[P2W19O69(H2O)]·24H2O precursor with Ln(NO3)3·nH2O and Co(NO3)2·6H2O in an aqueous potassium chloride solution. All the compounds were isolated as potassium salts and further characterized with different analytical techniques such as single-crystal X-ray diffraction, Fourier transform infrared spectroscopy, high-resolution electrospray ionization mass spectrometry, elemental analysis by inductively coupled plasma atomic emission spectroscopy, magnetic measurement, and thermogravimetric analysis. Single-crystal X-ray diffraction analysis of the compounds reveals that all these compounds are isostructural and crystallized in the orthorhombic crystal system in space group Iba2. The polyanions contain the α-1,5 isomer of dicobalt-substituted α-Keggin phosphotungstate, which sandwiched lanthanoid cation and formed novel heterometallic dimer species. The temperature-dependent magnetic susceptibilities of 1a, 2a, 4a, and 7a-10a indicate the dominant contribution of the ferromagnetic interaction between Co(II) and Co(II) within the cluster, while the antiferromagnetic interaction between Co(II) and Ln(III) dominates for 3a, 5a, and 6a. The isothermal magnetizations of 1a-10a show a gradual increase in magnetization at low fields and do not reach saturation even at 50 kOe.

First Orange Fluorescence Composite Film Based on Sm-Substituted Tungstophosphate and Its Electrofluorochromic Performance

We chose a Sm-containing sandwich-type tungstophosphate K3Cs8[Sm(PW11O39)2]·10H2O (SmPW11) as a molecular dyad, which contains photoluminescence and electrochromism components in a skeletal structure, and investigated its electrofluorochromic performance both in solution and in composite films. First, the electrochemical activity and luminescence property of SmPW11 were studied in different pH solutions to determine the optimal pH solution medium; and then, the electrofluorochromic performance of SmPW11 was investigated under the optimized pH solution medium. Subsequently, the composite films containing SmPW11 were prepared on quartz substrates and conductive ITO substrates through a layer-by-layer (LbL) assembly method, using PDDA and PEI as molecular linkers. Characterization methods of the composite films include UV-vis spectra, fluorescence spectroscopy, cyclic voltammetry (CV), bulk electrolysis with coulometry, chronoamperometry, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Finally, in situ UV-vis and fluorescence spectroelectrochemical systems were used to research electrofluorochromic properties for the composite films under electrochemical modulation. The results indicate that the composite films display not only orange luminescence emission but also reversible orange luminescence switching behaviors manipulated by the redox process of tungstophosphate species PW11 via the energy transfer between the orange luminescence component Sm and electroreduced species of tungstophosphate PW11.

Coordination-Driven Self-Assembly of a 2D Graphite-Like Framework Constructed from High-Nuclear Ce10 Cluster Encapsulated Polyoxotungstates

It is challenging to explore and prepare high-nuclear lanthanide (Ln) cluster-encapsulated polyoxometalates (POMs). Herein, we fabricate an unprecedented Ce10-cluster-embedded polyoxotungstate (POT) (TMA)14H2[Ce(III)(H2O)6]{[Ce(IV)7Ce(III)3O6(OH)6(CO3)(H2O)11][(P2W16O59)]3}·41H2O (1) (TMA = tetramethyleneamine) by coordination-driven self-assembly strategy, which contains the largest Ce cluster [Ce(IV)7Ce(III)3O6(OH)6(CO3)(H2O)11] (Ce10) in all the Ln-containing POM chemistry to date. Self-assembly of the in situ dilacunary [P2W16O59](12-) fragments and mixed Ce(3+) and Ce(4+) ions by means of coordination-driven force results in a novel 2D graphite-like framework constructed from mixed-valent cerium(III/IV) cluster {Ce10} encapsulated poly(POT) units and Ce(3+) ions. The most remarkable feature is that the skeleton of the centrosymmetric Ce10-cluster-embedded POT trimer contains three dilacunary [P2W16O59](12-) fragments trapping a novel {Ce10} cluster via 18 terminal-oxo and three μ4-oxo atoms.

19-Tungstodiarsenate(III) Functionalized by Organoantimony(III) Groups: Tuning the Structure-Bioactivity Relationship

A family of three discrete organoantimony(III)-functionalized heteropolyanions-[Na{2-(Me2HN(+)CH2)C6H4Sb(III)}As(III)2W19O67(H2O)](10-) (1), [{2-(Me2HN(+)CH2)C6H4Sb(III)}2As(III)2W19O67(H2O)](8-) (2), and [{2-(Me2HN(+)CH2)C6H4Sb(III)}{WO2(H2O)}{WO(H2O)}2(B-β-As(III)W8O30)(B-α-As(III)W9O33)2](14-) (3)-have been prepared by one-pot reactions of the 19-tungstodiarsenate(III) precursor [As(III)2W19O67(H2O)](14-) with 2-(Me2NCH2)C6H4SbCl2. The three novel polyanions crystallized as the hydrated mixed-alkali salts Cs3KNa6[Na{2-(Me2HN(+)CH2)C6H4Sb(III)}As(III)2W19O67(H2O)]·43H2O (CsKNa-1), Rb2.5K5.5[{2-(Me2HN(+)CH2)C6H4Sb(III)}2As(III)2W19O67(H2O)]·18H2O·Me2NCH2C6H5 (RbK-2), and Rb2.5K11.5[{2-(Me2HN(+)CH2)C6H4Sb(III)}{WO2(H2O)}{WO(H2O)}2(B-β-As(III)W8O30)(B-α-As(III)W9O33)2]·52H2O (RbK-3), respectively. The number of incorporated {2-(Me2HN(+)CH2)C6H4Sb(III)} units could be tuned by careful control of the experimental parameters. Polyanions 1 and 2 possess a dimeric sandwich-type topology, whereas 3 features a trimeric, wheel-shaped structure, representing the largest organoantimony-containing polyanion. All three compounds were fully characterized in the solid state via single-crystal X-ray diffraction (XRD), infrared (IR) spectroscopy, and thermogravimetric analysis, and their aqueous solution stability was validated by ultraviolet-visible light (UV-vis) and multinuclear ((1)H, (13)C, and (183)W) nuclear magnetic resonance (NMR) spectroscopy. Effective inhibition against six different types of bacteria was observed for 1 and 2, and we could extract a structure-bioactivity relationship for these polyanions.

Ln12 -Containing 60-Tungstogermanates: Synthesis, Structure, Luminescence, and Magnetic Studies

A new class of hexameric Ln12 -containing 60-tungstogermanates, [Na(H2 O)6 ⊂Eu12 (OH)12 (H2 O)18 Ge2 (GeW10 O38 )6 ](39-) (Eu12 ), [Na(H2 O)6 ⊂Gd12 (OH)6 (H2 O)24 Ge(GeW10 O38 )6 ](37-) (Gd12 ), and [(H2 O)6 ⊂Dy12 (H2 O)24 (GeW10 O38 )6 ](36-) (Dy12 ), comprising six di-Ln-embedded {β(4,11)-GeW10 } subunits was prepared by reaction of [α-GeW9 O34 ](10-) with Ln(III) ions in weakly acidic (pH 5) aqueous medium. Depending on the size of the Ln(III) ion, the assemblies feature selective capture of two (for Eu12 ), one (for Gd12 ), or zero (for Dy12 ) extra Ge(IV) ions. The selective encapsulation of a cationic sodium hexaaqua complex [Na(H2 O)6 ](+) was observed for Eu12 and Gd12 , whereas Dy12 incorporates a neutral, distorted-octahedral (H2 O)6 cluster. The three compounds were characterized by single-crystal XRD, ESI-MS, photoluminescence, and magnetic studies. Dy12 was shown to be a single-molecule magnet.

Assembly of a large cerium(III)-containing tungstotellurites(IV) nanocluster: [Ce₁₀Te₈W₈₈O₂₉₈(OH)₁₂(H2O)₄₀]¹⁸⁻

A large lanthanide-containing tungstotellurites(iv) nanocluster Na18[Ce10Te8W88O298(OH)12(H2O)40]·54H2O () was synthesized by combining cerium linkers and TeO3(2-) heteroanion templates. The macroanion in consists of two identical [Te4W42O144(OH)6Ce4(H2O)13](14-) subunits and two triangle-shaped {W2O5Ce(H2O)7} linkers.

Synthesis, structure, spectroscopic and ferroelectric properties of an acentric polyoxotungstate containing 1:2-type [Sm(α-PW₁₁O₃₉)₂]¹¹⁻ fragment and D-proline components

An organic-inorganic hybrid mono-Sm(III) substituted phosphotungstate KNa3[HPro]₇[Sm(α-PW₁₁O₃₉)₂]·Pro·₁₈H₂O (1) (Pro=D-proline) has been synthesized in the conventional aqueous solution and structurally characterized by elemental analyses, inductively coupled plasma atomic emission spectrometry (ICP-AES) analyses, IR spectra, UV spectra, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA) and single-crystal X-ray diffraction. The molecule of 1 consists of a classical 1:2-type [Sm(α-PW₁₁O₃₉)₂](11-) fragment and free D-proline components. It should be pointed out that the synergistic action between the in-situ formed chiral [Sm(α-PW₁₁O₃₉)₂](11-) fragment and chiral D-proline components results in the formation of the chiral 1. The luminescence emission of 1 reveals three characteristic bands that derive from the (4)G₅/₂→(6)H₅/₂, (4)G₅/₂→(6)H₇/₂ and (4)G₅/₂→(6)H₉/₂ transitions of the Sm(III) cation as well as the synergistic contribution of the O→W transitions of [α-PW₁₁O₃₉](7-) moieties and a π(*)-n or π(*)-π transitions of Pro. Its ferroelectric behavior has been measured.

Synthesis and magnetic properties of tartrate-bridging rare-earth-containing polytungstoarsenate aggregates from an adaptive precursor [As2W19O67(H2O)]14−

Six S-shaped tartrate-bridging rare-earth-substituted polytungstoarsenates [RE₂(C₄H₄O₆)(C₄H₂O₆)(As W₉O₃₃)]₂¹⁸⁻ (Ho^III (1), Er^III (2), Tm^III (3), Yb^III (4), Lu^III (5), Y^III (6)) were synthesized under conventional solution conditions.

Double-malate bridging tri-lanthanoid cluster encapsulated arsenotungstates: syntheses, structures, luminescence and magnetic properties

Five members of a new family of POM-ligated double-malate bridging tri-lanthanoid clusters have been synthesized and characterized.

Significant developments in rare-earth-containing polyoxometalate chemistry: synthetic strategies, structural diversities and correlative properties

In this article, the major progress in rare-earth containing polyoxometalates made in the past decade involving synthetic strategies, structural characteristics and some significant properties related to optics, catalysis and magnetism is highlighted and discussed.

Syntheses, crystal structure, electrochemistry and luminescence properties of lanthano–germanotungstates

[Ln(α-GeW₁₁O₃₉)₂]¹³⁻ (Ln = La^III and Ce^III) and [{Ln(μ-CH₃COO)GeW₁₁O₃₉(H₂O)}₂]¹²⁻ (Ln = Pr^III, Nd^III and Sm^III) complexes were synthesized using a one-pot reaction. Similar complexes were isolated and their electrochemical and photochromic properties were studied.

Construction of polyoxometalates from dynamic lacunary polyoxotungstate building blocks and lanthanide linkers

New polyoxometalates have been constructed from the dynamic building block {B-α-Sb^IIIW₉O₃₃} and lanthanide (Ln) linkers via a stepwise synthetic strategy, exhibiting luminescent properties with their Tb- and Dy-derivatives.

Dimeric complexes of rare-earth substituted Keggin-type silicotungstates: syntheses, crystal structure and solid state properties

A series of rare-earth substituted dimeric complexes of Keggin-type silicotungstates were synthesized and characterized using various analytical techniques like SCXD, photoluminescence, ¹H and ¹³C NMR spectroscopy.

From a versatile arsenotungstate precursor to a large lanthanide-containing polyoxometalate–carboxylate hybrid

From the versatile precursor [As₂W₁₉O₆₇(H₂O)]¹⁴⁻ through combined disassembly and reassembly processes, the large, POM–carboxylate hybrid K₁₄Li₄H₂₀[As₆W₅₈O₂₀₆Ce₄(pydc)₂(H₂O)₆]·44H₂O was obtained in conventional aqueous solution.

Lanthanoid containing phosphotungstates: the syntheses, crystal structure, electrochemistry, photoluminescence and magnetic properties

A series of Peacock and Weakley type dimers was synthesized in a one pot reaction with high yield using ligand [P₂W₁₉O₆₉(H₂O)]¹⁴⁻. All nano clusters were structurally characterized by various analytical techniques.