In Situ Ligand-Transformation-Assisted Assembly of a Polyoxometalate and Silver-Phosphine Oxide Cluster for Colorimetric Detection of Phenol Contaminants.

In situ ligand transformation strategies represent an efficient pathway for constructing function-oriented polyoxometalate (POM)-based crystalline materials. Herein, three POM-based hybrid networks were synthesized through in situ transformation of the phosphine ligand, formulated as [Ag(dppeo)][HPMoO]·5HO (), [Ag(dedpo)][SiWO]·6HO (), and [Ag(dppeo)][PWO]·3HO () (dedpo = (2-(diphenylphosphaneyl)ethyl)diphenylphosphine oxide; dppeo = ethane-1,2-diylbis(diphenylphosphine oxide)). During the synthesis of these compounds, the 1,2-diphenylphosphine ethane molecule underwent in situ oxidation, transforming into dppeo and dedpo ligands, respectively.

Ruthenium Complexes with NNN-Pincer Ligands for N-Methylation of Amines Using Methanol.

A series of ruthenium complexes () bearing new NNN-pincer ligands were synthesized in 58-78% yields. All of the complexes are air and moisture stable and were characterized by IR, NMR, and high-resolution mass spectra (HRMS). In addition, the structures of were confirmed by X-ray crystallographic analysis.

Fullerene-like Niobovanadate Cage Built from {(Nb)V } Pentagon.

The striking aesthetic appeal of fullerene-like clusters has captured the interest of researchers. Nevertheless, the assembly of fullerene-like polyoxovadanadate (POV) cages remains a significant challenge due to the scarcity of suitable pentagonal motif. Herein, we have successfully synthesized the first fullerene-like all-inorganic POV cage, {(V O)V Nb O (H O) } (V Nb ), by introducing Nb into the POVs.

A Rhombus-Like Tetrameric Vanadoniobate Containing Pseudo-Sandwich-Type {Li ⊂ VO(NbO)} and Its Electrocatalytic Activity for the Selective Oxidation of Benzyl Alcohol.

Ongoing research on V-containing polyoxoniobates (PONbs) is driven by their diverse structures and potential applications. Although Lindqvist-type {NbO} is a widely used building block in PONbs, vanadoniobates based on {NbO} and/or its derivatives are still very limited. Herein, a discrete vanadoniobate, LiNaK[Li ⊂ VNbO]·45HO (), has been synthesized by a hydrothermal method, which shows a rhombus-like tetrameric structure composed of two {VO(NbO)} and two {Li ⊂ VO(NbO)} subunits derived from {NbO}.

Gallium(III)- and Thallium(III)-Encapsulated Polyoxopalladates: Synthesis, Structure, Multinuclear NMR, and Biological Activity Studies.

Three gallium(III)- and thallium(III)-containing polyoxopalladates (POPs) have been synthesized and structurally characterized in the solid state and in solution, namely, the phosphate-capped 12-palladate nanocubes [XPdO(PO)] (X = Ga, ; X = Tl, ) and the 23-palladate double-cube [TlPdPO(OH)] (). The cuboid POPs, and , are solution stable as verified by the respective P, Ga, and Tl nuclear magnetic resonance (NMR) spectra. Of prime interest, the spin-spin coupling schemes allowed for an intimate study of the solution behavior of the Tl-containing POPs via a combination of P and Tl NMR, including the stoichiometry of the major fragments of .

{V } Ring Sandwiched Polyoxoniobate as Molecular Electrocatalyst for Oxidant-Free Synthesis of Sulfoxides.

Electrocatalytic oxidation of organic molecules to value-added chemicals has attracted recent attention. Although a series of transition metal based electrocatalytic materials have been developed, the lack of precise structure information generates great challenges in understanding the catalytic mechanism at a molecular level. Herein, we present the synthesis and characterization of a molecular electrocatalyst, Na K H [(VO) (α-TeNb O ) ] ⋅ 31H O ⋅ 2.

Arsenic(III)-Capped 12-Tungsto-2-Arsenates(III) [M(AsWO)(AsOH)] (M = Cr, Fe, Sc, In, Ti, Mn) and Their Magnetic Properties.

Six arsenic(III)-capped 12-tungsto-2-arsenates(III) of the type [M(AsWO)(AsOH)] (M = Cr, ; Fe, ; Sc, ; In, ; Ti, ; Mn, ) have been synthesized in aqueous medium by direct reaction of the elements using a one-pot strategy and structurally characterized by FT-IR spectroscopy, single-crystal XRD, and elemental analysis. Polyanions - are comprised of two octahedrally coordinated guest metal ions M sandwiched between two {AsW} units, resulting in a structure with point-group symmetry. Polyanions - contain tri- and tetravalent metal ion guests M (M = Cr, Fe, Sc, In, and Ti, respectively), and they have one {AsOH} group grafted on each {AsW} unit, whereas the divalent Mn-containing derivative has two such {AsOH} groups grafted on each {AsW} unit.

Synthesis, structure, electrochemistry and magnetism of cobalt-, nickel- and zinc-containing [M(OH)(HO)(α-SiWO)] (M = Co, Ni, and Zn).

Interaction of the trilacunary 9-tungstosilicate [A-α-SiWO] with cobalt(ii), nickel(ii) and zinc(ii) ions in pH 9 aqueous medium at room temperature led to the formation of the respective M-containing heteropolytungstates [M(OH)(HO)(α-SiWO)] (M = Co (1), Ni (2), and Zn (3)). Polyanions 1-3 were characterized in the solid state by single-crystal XRD, FT-IR spectroscopy, and thermogravimetric and elemental analyses. Electrochemical studies showed that the Co ions in 1 can be oxidized to Co and the CVs of the W centers of the polyanions feature well-defined and chemically reversible reduction waves.

Imidazole-Functionalized Polyoxometalate Catalysts for the Oxidation of 5-Hydroxymethylfurfural to 2,5-Diformylfuran Using Atmospheric O.

Biomass as a sustainable and abundant carbon source has attracted considerable attention as a potential alternative to petroleum resources. The selective oxidation of 5-hydroxymethylfurfural (HMF), a versatile platform molecule, to value-added 2,5-diformylfuran (DFF) provides an efficient pathway for biomass valorization. Herein, three discrete imidazole-functionalized polyoxometalates (POMs), HPMoVO(VO)[(VO)(IM)]·HO·(IM) (IM = 1-methylimidazole, = 4, = 8 for ; IM = 1-ethylimidazole, = 4, = 9 for ; IM = 1-propylimidazole, = 0, = 4 for ), have been successfully synthesized by a facile solvothermal method and thoroughly characterized by routine techniques.

Assembly of Lanthanide-Containing Tungstotellurates(VI): Syntheses, Structures, and Catalytic Properties.

Lanthanide (Ln)-containing polyoxometalates (POMs) have attracted particular attention owing to their structural diversity and potential applications in luminescence, magnetism, and catalysis. Herein three types of Ln-containing tungstotellurates(VI) (Ln = Dy, Ho, Er, Tm, Yb, and Lu), dimeric (DMAH) [H {Ln(HO)[TeWO]}]mHO (abbreviated as {LnTeW}; DMAH = dimethylammonium), mono-substituted (DMAH)Na{HLn(HO)[TeWO]}mHO (abbreviated as {LnTeW}), and three-dimensional (3D) inorganic frameworks (DMAH) {H Ln(HO)[TeWO]}mHO (abbreviated as {LnTeW}), have been synthesized by using simple metal salts and characterized by single-crystal X-ray diffraction and other routine techniques. Interestingly, the assembly of these POMs is pH dependent.

Shape and Size Tuning of Bi-Centered Polyoxopalladates: High Resolution Bi NMR and Bi Radiolabeling for Potential Pharmaceutical Applications.

We have discovered five bismuth(III)-containing polyoxopalladates (POPs) which were fully characterized by solution and solid-state physicochemical techniques: the cube-shaped [BiPdO(AsPh)] (BiPdAsL), [BiPdO(AsCHN)] (BiPdAsL), and [BiPdO(AsCHCOO)] (BiPdAsL) as well as the star-shaped [BiPdO(PO)H] (BiPdP) and [BiPdO(PPh)] (BiPdPL), respectively. The organically modified capping groups phenylarsonate, -azidophenylarsonate, and -carboxyphenylarsonate were chosen as the azido (-N) and carboxyl (-COOH) groups open up opportunities to covalently conjugate (via click reaction, amide coupling, etc.) with targeting vectors.

Self-assembly of polyoxovanadate-capped polyoxoniobates and their catalytic decontamination of sulfur mustard simulants.

We report the synthesis and characterization of two discrete vanadoniobates, H6Cs4Na5K7[V5Nb23O80]·28H2O (1) and H6Cs4Na5K8[V6Nb23O81]·34H2O (2), based on a brand new {Nb23} and a 5/6-nuclear polyoxovanadate cap. The two vanadoniobates as heterogeneous catalysts can effectively promote the oxidative decontamination of sulfur mustard simulants.

Mono- and Di-Sc-Substituted Keggin Polyoxometalates: Effective Lewis Acid Catalysts for Nerve Agent Simulant Hydrolysis and Mechanistic Insights.

Recently, the hydrolysis of nerve agents by Lewis acid catalysts has attracted considerable attention. The development of molecular catalysts, such as polyoxometalates (POMs) with Lewis acidic sites, is helpful to improve degradation efficiency and understand the catalytic mechanism at a molecular level. Herein, two novel Keggin-type POMs, namely, mono-Sc-substituted K[Sc(HO)PWO]·22HO·2(CHCOOK) () and di-Sc-substituted Na[Sc(CHCOO)PWO]·10HO·2CHCOONa (), have been successfully synthesized and thoroughly characterized by routine techniques.

Copper(ii)-containing tungstotellurates(vi): syntheses, structures and their catalytic performances in selective oxidation of thioethers.

We report the syntheses and structures of two new copper(ii)-containing tungstotellurates(vi) Na[Te WOCu(HO)]·7HO (TeWCu) and Na[TeWOCu(NHCHCO)]·6HO (TeWCu). The two compounds were synthesized by a simple one-pot method and characterized by single-crystal X-ray diffraction (XRD), powder XRD, FT-IR spectroscopy, elemental analysis, and thermogravimetric analysis in the solid state. Furthermore, their catalytic properties for the selective oxidation of thioethers were also studied systematically.

Near-infrared photothermal conversion of stable radicals photoinduced from a viologen-based coordination polymer.

Upon simple UV-visible irradiation, a viologen-based coordination polymer was transformed to a highly stable radical, protected against quenching by a densely packed structure. The photo-generated radical exhibited a remarkable near-infrared (NIR) photothermal effect with good recyclability and high conversion efficiency. To our knowledge, this is the first example of a crystalline viologen-based coordination polymer that functions as a NIR photothermal material by forming stable radicals.

Tetra-(-tolyl)antimony(III)-Containing Heteropolytungstates, [{(-tolyl)Sb}(-α-XWO)] (X = P, As, or Ge): Synthesis, Structure, and Study of Antibacterial and Antitumor Activity.

We have synthesized and structurally characterized three tetra-(-tolyl)antimony(III)-containing heteropolytungstates, [{(-tolyl)Sb}(-α-XWO)] [X = P (), As (), or Ge ()], in aqueous solution using conventional, one-pot procedures. The polyanions , , and were fully characterized in the solid state and in solution and were shown to be soluble and stable in aqueous medium at pH 7. Biological studies demonstrated that all three polyanions possess significant antibacterial and antitumor activities.

A Hydrolytically Stable Vanadium(IV) Metal-Organic Framework with Photocatalytic Bacteriostatic Activity for Autonomous Indoor Humidity Control.

Metal-organic frameworks (MOFs) with long-term stability and reversible high water uptake properties can be ideal candidates for water harvesting and indoor humidity control. Now, a mesoporous and highly stable MOF, BIT-66 is presented that has indoor humidity control capability and a photocatalytic bacteriostatic effect. BIT-66 (V (O) (H O)(BTB) ), possesses prominent moisture tunability in the range of 45-60 % RH and a water uptake and working capacity of 71 and 55 wt %, respectively, showing good recyclability and excellent performance in water adsorption-desorption cycles.

Indium in Polyoxopalladate(II) Chemistry: Synthesis of All-Acetate-Capped [InPdO(OAc)] and Controlled Transformation to Phosphate-Capped Double-Cube and Monocube.

We have prepared the indium(III)-centered, all-acetate-capped polyoxopalladate(II) nanocube [InPdO(OAc)] (), which can be further used as precursor to form the phosphate-capped (i) double-cube [InPdO(OH)(PO)(POOH)] () and (ii) monocube [InPdO(PO)] (). All three novel polyoxopalladates (POPs) were synthesized using conventional one-pot techniques in aqueous solution and characterized in the solid state (single-crystal XRD, IR, elemental analysis), in solution (In, P, and C NMR), and in the gas phase (ESI-MS).

Tetravalent Metal Ion Guests in Polyoxopalladate Chemistry: Synthesis and Anticancer Activity of [MOPd(PO)] (M = Sn, Pb).

The first two examples of polyoxopalladates(II) (POPs) containing tetravalent metal ion guests, [MOPd(PO)] (M = Sn, Pb), have been prepared and structurally characterized in the solid state, solution, and gas phase. The interactions of the metal ion guests and the palladium-oxo shell were studied by theoretical calculations. The POPs were shown to possess anticancer activity by causing oxidative stress inducing caspase activation and consecutive apoptosis of leukemic cells.

Discrete Polyoxopalladates as Molecular Precursors for Supported Palladium Metal Nanoparticles as Hydrogenation Catalysts.

We have used discrete polyoxopalladates(II) (POPs) of the MPdX nanocube- and PdX nanostar-types (M = central metal ion, X = capping group) as molecular precursors (diameter ca. 1 nm) for the formation of supported (SBA-15) metallic nanoparticles. These materials proved to be highly active in the hydrogenation of o-xylene.

Self-Assembly of Ln(III)-Containing Tungstotellurates(VI): Correlation of Structure and Photoluminescence.

The generation of five types of Ln(III)-containing tungstotellurates(VI), dimeric (DMAH)Na[H(WO){Ln(HO)(TeWO)}]· nHO (abbreviated as {LnTeW}; Ln = Eu, Gd, or Tb; DMAH = dimethylammonium), tetrameric (DMAH)Na[H{Ln(HO)(TeWO)}]· nHO (abbreviated as {LnTeW}, Ln = Eu or Gd), 2:2 dimeric (DMAH)[H{Tb(HO)(TeWO)}]·25HO (abbreviated as {TbTeW}), 1:1 monosubstituted (DMAH)Na[HTb(HO)(TeWO)]·21HO (abbreviated as {TbTeW}), and three-dimensional polymer (DMAH)[HTb(HO){TeWO}]·14HO (abbreviated as {TbTeW} ), provides insight into the rich condensation chemistry of lacunary and other Dawson-type polyoxometalates. The pH and the type of Ln source both dictate which of these new complexes form. To our knowledge, {LnTeW} is the highest-nuclearity tungstotellurate to date, and {TbTeW} and {TbTeW} contain the first lacunary {TeWO}.

Dithallium(III)-Containing 30-Tungsto-4-phosphate, [TlNa(HO)(PWO)]: Synthesis, Structural Characterization, and Biological Studies.

Here we report on the synthesis and structural characterization of the dithallium(III)-containing 30-tungsto -4-phosphate [TlNa(HO){PWO}] (1) by a multitude of solid-state and solution techniques. Polyanion 1 comprises two octahedrally coordinated Tl ions sandwiched between two trilacunary {PW} Wells-Dawson fragments and represents only the second structurally characterized, discrete thallium-containing polyoxometalate to date. The two outer positions of the central rhombus are occupied by sodium ions.

Three Pd-decavanadates with a controllable molar ratio of Pd to decavanadate and their heterogeneous aerobic oxidation of benzylic C-H bonds.

By the combination of Pd-complexes and [VO], three Pd-decavanadate compounds [Pd(NH)][VO]·8HO (1), [Pd(deta)(HO)](NH)[VO]·2HO (2) (deta = diethylenetriamine) and [Pd(dpa)](Hdpa)(EtNH)[VO]·2HO (3) (dpa = 2,2'-dipyridylamine) have been successfully synthesized and thoroughly characterized using single X-ray diffraction (SXRD), powder X-ray diffraction (PXRD), infrared spectroscopy (FT-IR) and elemental analyses (EA). Interestingly, in the three compounds, the molar ratios of Pd to decavanadate vary from 3 : 1 to 1 : 1 by changing N-ligands. The three Pd-decavanadates as heterogeneous catalysts are active in the aerobic oxidation of benzylic hydrocarbons under solvent-free conditions without adding any additives and co-catalysts.

Rational Design of Organically Functionalized Polyoxopalladates and Their Supramolecular Properties.

The Sr -centered 12-palladate(II) open-cube {SrPd (OAc) } has been systematically evolved by substitution of the three acetate ligands by a library of saturated carboxylic acids with increasing chain lengths leading to four novel polyoxopalladates(II) with the formula [SrPd O (OH) (PhAsO ) (L) ] (SrPd L , L=C H COO, n=2 to 5). These first examples of surfactant-type polyoxopalladates with a hydrophilic metal-oxo unit and three hydrophobic alkyl chains were characterized in the solid state (single-crystal XRD, FTIR, TGA), in solution ( H, C NMR spectroscopy), and in the gas phase (ESI-MS). The two polyanions SrPd L with chain lengths of 5 and 6 are the first examples of polyoxopalladates that are soluble and stable in organic media.