Assembly of Four Ternary Polyoxometalate Aggregates by Integrating Presynthesized {XWNbO} (X = Si/Ge) Units Using Molybdenum-Oxo Clusters.

Polyoxometalates (POMs) have good potential for applications in different fields, including conducting materials, optics, and electrocatalysis. Of particular significance is the synthesis and development of addendum POMs. Molybdenum-oxo clusters, which are renowned for their diverse structures and electronic properties, were utilized to facilitate the synthesis of innovative materials.

A Two-Dimensional Layered Heteropolyoxoniobate Based on Cubic Sn(IV)-Containing {SnNbO} Cages with Good Proton Conductivity Property.

The first example of a Sn(IV)-containing heteropolyoxoniobate KH[Cu(en)]{[Sn(OH)] (HNbO)}·2en·88HO () is built from nanoscale high-nuclearity cubic {[Sn(OH)](HNbO)} cluster and [Cu(en)] complexes. The cubic {[Sn(OH)](HNbO)} cage is composed of eight {NbO} clusters and 12 SnO octahedrons. The eight {NbO} fragments are situated at the vertices of the cubic cage, while the 12 SnO octahedrons are positioned along the edges of the cubic cage.

A Rare Inorganic-Organic Hybrid Polyoxoboroniobate Based on Pagoda-Shaped {LiBNbO} Clusters and {Cd(-en)(-en)} Complexes.

A new inorganic-organic hybrid polyoxoboroniobate {HK[Cu(-en)(HO)][Cu(-en)][Cd(-en)(-en)][LiBNbO]·79HO} (, en = ethylenediamine), is built from pagoda-shaped {LiBNbO} clusters, linear {Cd(-en)(-en)} bridging units, and copper-amine complexes. The {LiBNbO} cluster represents the first example of combining oxoboron clusters with polyoxoniobate clusters (PONbs). It consists of an unusual HPONb fragment {LiNbO}, a fused-ring structural boroniobate cluster {BNbO}, and a classical Lindqvist {NbO} fragment.

A water-soluble mixed-valent {Mn} cluster embedded heteropolyoxoniobate with magnetic properties.

A rare all-inorganic high-nuclearity mixed-valent {Mn} cluster embedded polyoxoniobate, KH{(TeNbO)(NbO)(TeNbO)[(TeO)(MnII7MnIII4O)]}·97HO (1), has been synthesized by a one-pot reaction. Compound 1 contains the largest manganese cluster {Mn} core among polyoxoniobates reported to date. {Mn} consists of three quasi-cubane {MnO} units and is simultaneously encapsulated by lacunary α-Keggin {TeNbO} and Lindqvist {NbO} units.

A Spectroscopic Method for Distinguishing Two Novel Sandwich-Type Tungsten Oxide Cluster Compounds.

This study introduces two novel sandwich-type tungsten-oxygen cluster compounds synthesized by hydrothermal methods, H(CHNH){Na(HO)[Mn(HO)(GeWO)]} (Compound 1) and H(CHNH){Na(HO)[Co(HO)(GeWO)]}·17HO (Compound 2). The two compounds comprise cluster anions [GeWO] coordinated with transition metal atoms, either Mn or Co, and are stabilized by organic ligands. These compounds are crystallized in the hexagonal crystal system and P6/m space group.

Development of Stable Water-Soluble Supratomic Silver Clusters Utilizing A Polyoxoniobate-Protected Strategy: Giant Core-Shell-Type Ag@Nb Fluorescent Nanocluster.

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.

An Organodiphosphate-Containing Polyoxoniobate Ring and Its Assembly into a Three-Dimensional Framework through Hydrogen Bonding.

In this work, a novel organodiphosphate-containing inorganic-organic hybrid polyoxoniobate (PONb) ring {(POCHCHPOH)NbO} () has been achieved by a one-pot hydrothermal method. The ring is constructed from a tetragonal {NbO} motif and four {POCHCHPOH} ligands. Interestingly, can be joined together via K-HO clusters {K(HO)(OH)} to form one-dimensional chains {[K(HO)(OH)]} and further linked by {Cu(en)} (en = ethylenediamine) complexes, resulting in a three-dimensional supramolecular framework {[Cu(en)][K(HO)(OH)]}·3en·HO ().

A 3D heteropolyoxoniobate framework based on heart-shaped {TeNbO} clusters with proton conductivity property.

A 3D tellurium-substituted heteropolyoxoniobate framework HKNa[Cu(en)][Cu(en)(HO)]{[(TeNbO)(μ-OH)]}·24HO (1, en = ethylenediamine) with a 6-connected topology is built from heart-shaped {TeNbO} clusters and copper complexes. The {TeNbO} cluster represents the new tellurniobate structure type with a 19-nuclearity Nb cluster. It consists of two new monovacant Lindqvist {NbO} clusters, one boat-shaped {NbO} cluster and two TeO anions.

A tetrahedron-shaped polyoxoantimotungstate encapsulating a hexanuclear octahedral lanthanide-oxo cluster for an amperometric bromate sensor.

An inorganic hexalanthanide-oxo-cluster-encapsulated antimotungstate, KNaH[Nd(OH)(HO)(B-α-SbWO)]·67HO (1), has been successfully synthesized by a facile one-step hydrothermal reaction method. The tetrahedron-shaped two-shell {Nd(OH)(HO)(B-α-SbWO)}(1a) polyanion is composed of a novel pure lanthanide-oxo {Nd(μ-OH)(HO)} octahedron and {(B-α-SbWO)} tetrahedron. After being effectively loaded onto a glassy carbon electrode (GCE) by electrostatic adsorption using polydiallyldimethyl ammonium chloride (PDDA)-functionalized multi-walled carbon nanotubes (MWCNTs), compound 1 exhibits electrochemical activity for the reduction of bromate ions with good selectivity, a high sensitivity of 186 μA mM and a detection limit that has reached 1.

Two Unprecedented Germanoniobate Frameworks Based on High-Nuclearity Peanut-Shaped {GeNb} Clusters.

By variation of the amount of GeO, two organic-inorganic hybrid germanoniobate frameworks with 6-connected and 10-connected topologies were constructed from peanut-shaped {α-GeNb} and {β-GeNb} clusters, respectively. The {α-GeNb} and {β-GeNb} clusters contain the most Ge centers of germanoniobates reported so far. The compounds exhibit proton conduction properties with a conductivity of 3.

Photo-Activating Biomimetic Polyoxomolybdate for Boosting Oxygen Evolution in Neutral Electrolytes.

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, MV [β-Mo O ] (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 and Tafel slope decrease by 49 mV and 62.

Reversible Thermochromism and Stable Resistance Switching Behaviors Based on a Co(III)-Complex-Linked Polyoxoniobate.

A 3D Co(III)-complex hybrid polyoxoniobate framework Na(HO)[Co(phen)(4,4'-bipy)(NbO)]·19HO () has been constructed from [Co(phen)(4,4'-bipy)(NbO)] dimer units and 2D inorganic Na-O cluster layers. The Co(III) centers are coordinated with {NbO}, 4,4'-bipy and phen simultaneously. The [Co(phen)(4,4'-bipy)(NbO)] fragments link the Na-O cluster layers to generate a 3D metal complex-modified hybrid polyoxoniobate framework with π-π interactions between phenanthroline rings.

Development of a New Heteropolyoxotantalate Cluster for Multidimensional Polyoxotantalate Materials.

A unique heteropolyoxotantalate (hetero-POTa) cluster [POTaO] (PTa) was first developed using pyrophosphate as a key to open the ultrastable skeleton of the classical Lindqvist-type [TaO] precursor. The PTa cluster can serve as a general and flexible secondary building unit to create a family of brand-new multidimensional POTa architectures. This work not only promotes the limited structural diversity of hetero-POTa but also provides a practical strategy for new extended POTa architectures.

Oxalate-assisted assembly of two polyoxotantalate supramolecular frameworks with proton conduction properties.

An oxalate-assisted strategy was first developed for creating new polyoxotantalates (POTas). With this strategy, two brand-new POTa supramolecular frameworks based on uncommon dimeric POTa secondary building units (SBUs) were constructed and characterized. Interestingly, the oxalate ligand can not only serve as a coordination ligand to form unique POTa SBUs but also act as a key hydrogen bond acceptor to construct supramolecular architectures.

Cadmium-containing windmill-like heteropolyoxoniobate macrocycle with high yield for catalyzing Knoevenagel condensation.

A rare cadmium-containing windmill-like heteropolyoxoniobate macrocycle has been successfully synthesized with stable 1-D cyclic cluster aggregates. The compound exhibited promising basic catalytic ability for Knoevenagel condensation with a high yield under mild reaction conditions and high cycling stability. The theoretical calculation showed that the promising basic catalytic ability is due to the dense and stronger basic sites of the surface terminal O atoms.

Proton-Conductive Polyoxometalate Architectures Constructed from Lanthanide-Incorporated Polyoxoniobate Cages.

Two new extended polyoxometalate (POM) architectures based on lanthanide-incorporated polyoxoniobate (Ln-incorporated PONb) cages, namely, H[Cu(en)]{K(HO)[Cu(en)][Cu(trz)(en)(OH)][DyCu(en)(CO)(HO)(OH)][Dy(HO)][DyNbO(HO)]}·60HO (, en = ethylenediamine) and H[Cu(en)]{[Cu(en)][Dy(CO)(HO)][(Nb(OH)(HO)O]}·54HO (), 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 and were studied.

A Three-Dimensional (3D) Indium-Containing Polyoxoniobate Framework Based on {InNb} Helical Pillars.

A rare 3D Indium-containing polyoxoniobate framework {H[Cu(en)(HO)][Cu(en)][In(en)][Nb-O(OH)(HO)]{NbO(OH)(HO)]}·68HO(), based on the In-containing polyoxoniobate cluster, {[In(en)][NbO(OH)(HO)][NbO(OH)(HO)]} ({InNb}) and [Cu(en)] linkers has been successfully synthesized. The nest-like cluster {InNb} is constructed from one brand-new V-shaped {NbO}, two triangle-shaped {NbO} and five [In(en)]. The [In(en)] fragments link {NbO} and {NbO} units into unique {InNb} helical pillars.

Two high-nuclearity isopolyoxoniobates containing {Nb O}-based helical nanotubes for the decomposition of chemical warfare agent simulants.

Two inorganic-organic hybrid isopolyoxoniobates (1 and 2) based on new high-nuclearity {NbO} clusters have been synthesized under hydrothermal conditions. In particular, the combination of the unique {NbO} clusters with copper-amine complexes has led to rare helical nanotubes, which are further linked by alkali metal cations or copper-amine complexes into two 2D similar bamboo-raft-like layered networks (1 and 2), respectively. Compound 1 exhibits effective base-catalytic decomposition of chemical warfare agent simulants dimethyl methylphosphonate (DMMP) and diethyl cyanophosphonate (DECP).

3d-4f Heterometallic cluster incorporated polyoxoniobates with magnetic properties.

A series of 3d-4f heterometallic cluster incorporated polyoxoniobates (PONbs) with different magnetic properties were first made and characterized. This work not only provides a promising strategy to make new heterometallic cluster incorporated PONbs but also demonstrates an ideal model to probe how transition-metal ions influence the magnetic property of PONbs.

Luminescent cluster-organic frameworks constructed from predesigned supertetrahedral {LnZn} secondary building units.

3d-4f heterometallic supertetrahedral clusters with the formula of LnZn(μ-O)L(CHCOO)(NO)(CHOH)(HO) (1-Ln, Ln = Eu, Gd, Tb, HL = 2-(hydroxymethyl)-2-(pyridin-4-yl)-1,3-propanediol) have been successfully introduced as stable secondary building units (SBUs) to construct new cluster-organic frameworks with tunable emission, demonstrating a promising strategy for developing new optical materials.

Proton conductive polyoxoniobate frameworks constructed from nanoscale {NbO} cages.

Nanoscale {Nb68O200} cages have been successfully employed as flexible and stable secondary building units to combine with bridging copper-amine complexes to construct two proton conductive polyoxoniobate frameworks, demonstrating a promising strategy for making new porous materials.

A Series of Cube-Shaped Polyoxoniobates Encapsulating Octahedral CuX O Clusters With Hydrolytic Decomposition for Chemical Warfare Agents.

This study reported a series of cube-shaped polyoxoniobates, {MCuO)(CuXO)(Nb(OH)O)} [M = Nb(1, 2), Ln(3), X = I(1, = 3, = 3; 2, = 5, = 1), Br(3, = 5, = 1)]. As the first octahedral CuXO cluster incorporated polyoxoniobate, the cube-shaped three-shell structure of {MCuO)(CuXO)(Nb(OH)O)} polyanion contains a {MCuO} body-centered cuboctahedron, a {CuXO} octahedron and a {Cu(Nb(OH)O)} cube. Compounds 1, 2, 3 show effective catalytic activities for the hydrolytic decomposition of chemical warefare agent simulants.