Solid State Coordination Chemistry of Oxomolybdenum Organoarsonate Materials

Copper-containing hybrid compounds based on extremely rare [V2Mo6O26]6– POM as water oxidation catalysts

Hybrid Cu/V/Mo compounds with rare [α-V₂Mo₆O₂₆]^6– and oxides prepared by their thermal degradation were used as catalysts for water oxidation.

A new 3D POMOF with two channels consisting of Wells–Dawson arsenotungstate and {Cl4Cu10(pz)11} complexes: synthesis, crystal structure, and properties

A new 3D POMOF based on Wells–Dawson arsenotungstate was prepared using a hydrothermal reaction. The POMOF exhibits a novel topological structure, photoluminescence properties, and excellent photocatalytic activity.

Organoarsonate Functionalization of Heteropolyoxotungstates

Functionalization of the {P₈W₄₈} polyoxotungstate (POT) archetype with aromatic organoarsonates results in the first homometallic {P₈W₄₈} derivatives, with the general formula [(RAs^VO)₄P^V₈W^VI₄₈O₁₈₄]³²⁻ [R = C₆H₅ (1) or p-(H₂N)C₆H₄ (2)]. Short As−O bonds here induce unusual bending of the otherwise rigid {P₈W₄₈} macrocycle, breaking its D_4h symmetry. The obtained species also represent the first lacunary POTs functionalized with organoarsonates and can potentially act as polyoxometalate precursors themselves. We elaborate solution stability in different aqueous media using ¹H and ³¹P NMR spectroscopy and possible pathways for subsequent transformations in aqueous solutions of the functionalized polyanions. Recrystallization of the K⁺/Li⁺/dimethylammonium salt of 2 from 4 M LiCl solution yielded a further functionalized POT, [(H₃NC₆H₄AsO)₃P₈W₄₈O₁₈₄H_x{WO₂(H₂O)₂}_0.4]^{(30.2−x)−} (3), revealing dissociation of the organoarsonate fragments in slightly acidic aqueous solutions followed by their rearrangement within the inner POT cavity.

Through strong As−O−W bonds, integration of organoarsonates into heteropolyoxometalates can result in structural distortion, as demonstrated for the seminal wheel-shaped {P₈W₄₈} polyoxotungstate archetype, which binds to up to four phenyl or aminophenyl arsonate groups.

A potential Cu/V-organophosphonate platform for tailored void spacesviaterpyridine mold casting

The reaction of appropriate copper and vanadium salts with tetratopic methane tetra-p-phenylphosphonic acid (MTPPA) in the presence of 2,2′:6′:2′′-terpyridine (terpy) yielded the three-dimensional bimetallic copper vanadium phosphonate framework [{Cu(terpy)}4Cu(VO2)4(MTPPA-H)2]·4H2O (1). Terpy has no net contribution to the three-dimensional structure providing a potential platform for void space formationviamold-casting. The structure was characterized by single-crystal X-ray diffraction and thermogravimetric analysis (TGA). Magnetic measurements were performed using a SQUID magnetometer. The crystal structure of the methanol solvate of the free ligand, MTPPA·MeOH, was analysed using Hirshfeld surfaces and fingerprint plots.

A novel 3D POMOF based on Wells–Dawson arsenomolybdates with excellent photocatalytic and lithium-ion battery performance

A novel 3D POMOF based on Wells–Dawson arsenomolybdates exhibits fluorescence property and efficient and stable photocatalytic activity for MB and RhB under UV irradiation and has also been evaluated as the anode material for LIBs.

A two-dimensional silver(I) coordination polymer constructed from 4-aminophenylarsonate and triphenylphosphane: poly[[(μ₃-4-aminophenylarsonato-κ³N:O:O)(triphenylphosphane-κP)silver(I)] monohydrate]

The title compound, {[Ag(C6H7AsNO3)(C18H15P)]·H2O}n, has been synthesized from the reaction of 4-aminophenylarsonic acid with silver nitrate, in aqueous ammonia, with the addition of triphenylphosphane (PPh3). The Ag(I) centre is four-coordinated by one amino N atom, one PPh3 P atom and two arsonate O atoms, forming a severely distorted [AgNPO2] tetrahedron. Two Ag(I)-centred tetrahedra are held together to produce a dinuclear [Ag2O2N2P2] unit by sharing an O-O edge. 4-Aminophenylarsonate (Hapa(-)) adopts a μ3-κ(3)N:O:O-tridentate coordination mode connecting two dinuclear units, resulting in a neutral [Ag(Hapa)(PPh3)]n layer lying parallel to the (101̄) plane. The PPh3 ligands are suspended on both sides of the [Ag(Hapa)(PPh3)]n layer, displaying up and down orientations. There is an R2(2)(8) hydrogen-bonded dimer involving two arsonate groups from two Hapa(-) ligands related by a centre of inversion. Additionally, there are hydrogen-bonding interactions involving the solvent water molecules and the arsonate and amine groups of the Hapa(-) ligands, and weak π-π stacking interactions within the [Ag(Hapa)(PPh3)]n layer. These two-dimensional layers are further assembled by weak van der Waals interactions to form the final architecture.

Photoluminescent lead(II) coordination polymers stabilised by bifunctional organoarsonate ligands

Four lead(II) coordination polymers were isolated under hydro(solvo)thermal conditions. The applied synthetic methodology takes advantage of the coordination behaviour of a new bifunctional organoarsonate ligand, 4-(1, 2, 4-triazol-4-yl)phenylarsonic acid (H2TPAA) and involves the variation of lead(II) reactants, metal/ligand mole ratios, and solvents. The constitutional composition of the four lead(II) coordination polymers can be formulated as [Pb2(TPAA)(HTPAA)(NO3)]·6H2O (1), [Pb2(TPAA)(HTPAA)2]·DMF·0.5H2O (DMF = N, N-Dimethylformamide) (2), [Pb2Cl2(TPAA)H2O] (3), and [Pb3Cl(TPAA)(HTPAA)2H2O]Cl (4). The compounds were characterized by single-crystal and powder x-ray diffraction techniques, thermogravimetric analyses, infra-red spectroscopy, and elemental analyses. Single-crystal x-ray diffraction reveals that 1 and 2 represent two-dimensional (2D) layered structures whilst 3 and 4 form three-dimensional (3D) frameworks. The structures of 1, 2, and 4 contain one-dimensional (1D) {PbII/AsO3} substructures, while 3 is composed of 2D {PbII/AsO3} arrays. Besides their interesting topologies, 1-4 all exhibit photoluminescence properties in the solid state at room temperature.

Exploring the coordination chemistry of bifunctional organoarsonate ligands: syntheses and characterisation of coordination polymers that contain 4-(1,2,4-triazol-4-yl)phenylarsonic acid

The syntheses, crystal structures, luminescent and magnetic properties of five triazol-phenylarsonic acid-based M(ii) coordination polymers are reported (M = Co, Cu, Mn, Cd).

Silver pyroarsonates obtained from Ag(I)-mediated in situ condensation of aryl arsonate ligands under solvothermal conditions

Four new layered silver(I) organoarsonates, namely, [Ag(3)(L(3))(CN)] (1) (H(2)L(3) = (PhAsO(2)H)(2)O), [Ag(3)(L(4))(CN)] (2) (H(2)L(4) = (2-NO(2)-C(6)H(4)-AsO(2)H)(2)O), [Ag(3)(HL(5))(H(2)L(5))] (3) (H(3)L(5) = 3-NO(2)-4-OH-C(6)H(3)-AsO(3)H(2)) and [Ag(2)(HL(5))] (4), were synthesized under solvothermal conditions. During the preparations of 1 and 2, condensation of organoarsonate ligands (H(2)L(1) = Ph-AsO(3)H(2); H(2)L(2) = 2-NO(2)-C(6)H(4)-AsO(3)H(2)) and the decomposition of acetonitrile molecules to cyanide anions occurred. Single crystals of H(2)L(4) ligand and compounds 1-4 were isolated, and their crystal structures have been determined by single crystal X-ray diffraction studies. In 1, the one-dimensional (1D) chains based on Ag(I) ions and {L(3)}(2-) anions are further interconnected by CN(-) into two-dimensional (2D) layers. In 2, adjacent Ag(I) ions within the silver(I) organoarsonate layer are further bridged by μ(4)-CN(-) anions with very short Ag···Ag contacts. In 3, the hexanuclear {Ag(6)O(12)} clusters are interconnected by bridging organoarsonate ligands into a silver(I) arsonate hybrid layer. In 4, the right-handed {Ag(4)O(4)} chains are further interconnected by organoarsonate ligands as well as additional Ag-O-Ag bridges into a novel silver(I) arsonate layer. Compounds 1 and 2 display red and orange-red emissions, respectively, which may be assigned to be an admixture of ligand-to-metal charge transfer (LMCT) and metal-centered (4d-5s/5p) transitions perturbed by Ag(I)···Ag(I) interactions. Upon cooling from room temperature to 10 K, compound 1 exhibits interesting temperature-dependent emissions.

Poly[bis{μ(2)-4-[3,5-bis(pyridin-4-yl)phenyl]pyridine}nona-μ(2)-oxido-tetraoxidocopper(II)tetramolybdenum(VI)]

The title compound, [CuMo(4)O(13)(C(21)H(15)N(3))(2)](n), was synthesized by the reaction of ammonium molybdate, copper acetate and 4-[3,5-bis(pyridin-4-yl)phenyl]pyridine (DPPP) in an aqueous medium under hydrothermal conditions. The two unique molybdenum centers and the copper center adopt MoO(4) tetrahedral, MoO(5)N octahedral and CuO(4)N(2) octahedral geometries, respectively. These polyhedra are connected to each other through corner-sharing to form a two-dimensional Cu-Mo-O layer, which is further linked by the DPPP ligands to form the three-dimensional inorganic-organic hybrid framework.

Copper-catalyzed oxidation of azolines to azoles

We report herein convenient, aerobic conditions for the oxidation of thiazolines to thiazoles and data regarding the oxidation mechanism. These reactions feature operationally simple and environmentally benign conditions and proceed in good yield to afford the corresponding azoles, thus enabling the inexpensive preparation of valuable molecular building blocks. Incorporation of a novel diimine-ligated copper catalyst, [((Mes)DAB(Me))Cu(II)(OH(2))(3)](2+) [(-)OTf](2), provides increased reaction efficiency in many cases. In other cases copper-free conditions involving a stoichiometric quantity of base affords superior results.