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 Highly Biocompatible Polyoxotungstate with Fenton-like Reaction Activity for Potent Chemodynamic Therapy of Tumors.

Integrating Fenton chemistry and nanomedicine into cancer therapy has significantly promoted the development of chemodynamic therapy (CDT). Nanoscale polyoxometalates (POMs), with their reversible redox properties, exhibit promising potential in developing outstanding CDT drugs by exploring their Fenton-like catalytic reactivity in tumor environments. However, such research is still in its infancy due to the challenges of acquiring POMs that are both easily prepared and possess ideal therapeutic effects, physiological solubility, biocompatibility and safety.

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.

Polyoxotungstate Featuring Zinc-Ion-Triggered Structural Transformation as An Efficient Electrolyte Additive for Aqueous Zinc-Ion Batteries.

It is promising but still challenging for the widespread application of aqueous zinc batteries due to the poor reversibility of the zinc anode caused by prevalent dendrite growth and pronounced interfacial side reactions. Herein, we report a rare soluble and water-stable high-nuclearity {NdSiW} polyoxotungstate. Interestingly, upon encountering Zn ions, the discrete {NdSiW} nanocluster undergoes a structural transformation to form an infinitely extended cluster-based {[Zn(HO)][NdSiW]} two-dimensional honeycomb layer, with which atomic-level Zn ion effects in reconstructing the layer are determined.

Site differentiation strategy for selective strontium uptake and elution within an all-inorganic polyoxoniobate framework.

Selective uptake and elution of trace amounts of hazardous radioactive Sr from large-scale high-level liquid waste (HLW) is crucial for sustainable development. Here, we propose a site differentiation strategy, based on the presence of distinct selective metal capture sites (concavity site and tweezer site) within the giant polyoxoniobate (PONb) nanoclusters of an all-inorganic PONb framework (FZU-1). Through this strategy, FZU-1 can not only effectively remove 98.

Indium-Assisted Construction of {SiNbO}-Based Aggregates and Their Assembly into Extended Polyoxoniobate Architectures.

In this research, indium ions were introduced into polyoxoniobates (PONbs) reaction systems to facilitate the construction of different {SiNbO}-based aggregates, including an {In(en){SiNbO}} (en = ethylenediamine) dimer, an {[InO][In(en)O]{SiNbO}} trimer, and an {[In(en)][InO][In(en)O]{SiNbO}} tetramer. Interestingly, these aggregates were further assembled into three uncommon extended PONb architectures in the presence of [Cu(en)] complexes, namely, H[Cu(en)(HO)][Cu(en)][Cu(en)]{[In(en)][K{SiNbO}(HO)]}·1.5en·16HO, H{[Cu(en)]{[Cu(en)][Cu(en)(HO)][In(HO)][In(en)(HO)(OH)]{SiNbO}}·5en·29HO, and H[Cu(en)][Cu(en)(HO)]{[Cu(en)]{[Cu(en)][Cu(en)(HO)][K(HO)][In(HO)][In(en)][In(OH)(en)]{SiNbO}}·7en·39HO.

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 Palladium-Containing Polyoxotungstate with Anisotropic Proton Conductivity.

Here, a case of bilayer heterojunction Pd-containing polyoxotungstate (POW), connecting a TePd ring and an Anderson-like TeW cluster, has been synthesized. The Anderson-like cluster is the first example in POW. The coordination of Pd in the ring with the S atom on the sulfo group breaks the traditional coordination configuration of Pd and O in polyoxometalates (POMs), enriching the structural types of Pd-containing POMs.

An Unusual Crystalline Porous Framework Constructed from Multitypes of Cages with Proton Conduction Property and Heterogeneous Catalytic Activity for Pyrazole Synthesis.

An unusual crystalline porous framework constructed from four types of cages, including all-inorganic Keggin-type polyoxometalate (POM) cages [HWO], organic hexamethylenetetramine (Hmt) cages, nanosized silver-Hmt coordination cages, and giant POM-silver-Hmt cages, was hydrothermally synthesized and structurally characterized. The framework features a highly symmetrical structure with one-dimensional nanoscale channels and holds good thermal/solvent stability, which endow it with proton conduction properties and heterogeneous catalytic activity for pyrazole. This paper not only contributes to broadening the structural diversity of cage-based crystalline porous framework materials but also sheds new light on the design of new functional framework materials.

An organophosphate 3d-4f heterometallic polyoxoniobate nanowire.

Four different structural compositions of organophosphate, 3d transition metal, 4f lanthanide and polyoxoniobate (PONb) are unified in a system for the first time to form a new type of organophosphate 3d-4f heterometallic inorganic-organic hybrid PONb nanowire. Interesting magnetic anisotropy and slow magnetic relaxation are found in the PONb nanowire.

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.

Tuning Electrocatalytic Water Oxidation Activity: Insights from the Active-Site Distance in LnCu Clusters.

Atomically precise metal clusters serve as a unique model for unraveling the intricate mechanism of the catalytic reaction and exploring the complex relationship between structure and activity. Herein, three series of water-soluble heterometallic clusters LnCu, abbreviated as LnCu-AC (Ln = La, Nd, Gd, Er, Yb; HAC = acetic acid), LnCu-IM (Ln = La and Nd; IM = Imidazole), and LnCu-IDA (Ln = Nd; HIDA = Iminodiacetic acid) are presented, each featuring a uniform metallic core stabilized by distinct protected ligands. Crystal structure analysis reveals a triangular prism topology formed by six Cu ions around one Ln ion in LnCu, with variations in Cu···Cu distances attributed to different ligands.

The mechanism governing the formation of intermolecular charge transfer bands: a series of polyoxomolybdates as a case study.

A series of proof-of-concept models of polyoxomolybdates with different protonated disubstituted aniline counterions and the same β-MoO polyanion were synthesized to study the mechanism governing the formation of the intermolecular charge transfer (inter-CT) band.

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.

New group IIIA metal phosphate-oxalates containing dimethylammonium cations with proton conductivity.

Three new group IIIA metal phosphate-oxalate (MPO) compounds, namely [(CH)NH][M(HPO)(HPO)(CO)] (M = Al (1), Ga (2)) and [(CH)NH][In(HPO)(HPO)(CO)]·HO (3), have been synthesized. Their crystal structures feature an anionic layer with the topology net. In particular, 1 displays a proton conductivity () of 9.

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.

Core-Shell-Type All-Inorganic Heterometallic Nanoclusters: Record High-Nuclearity Cobalt Polyoxoniobates for Visible-Light-Driven Photocatalytic CO Reduction.

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 {Co Nb O }, 54-nuclearity {Co Nb O }, 62-nuclearity {Co Nb O } and 87-nuclearity {Co Nb O }. 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.

Photochromic Polyoxoniobates with Photoinduced "D-f-A" Electron Transfer Mechanism.

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.