The grafting of the triangular 1,3,5-benzene tricarboxylate linkers (denoted trim) on tetrahedral ε-Keggin polyoxometalates (POMs) capped by Zn(II) ions, formed in situ under hydrothermal conditions, has generated three novel POM-based metal organic frameworks (POMOFs). (TBA)(3)[PMo(V)(8)Mo(VI)(4)O(36)(OH)(4)Zn(4)][C(6)H(3)(COO)(3)](4/3)·6H(2)O (ε(trim)(4/3)) is a 3D open-framework built molecular Keggin units connected trim linkers, with channels occupied tetrabutylammonium (TBA)...

The sandwich-type polyoxometalate (POM) [(PW9O34)2Co4(H2O)2]10– was immobilized in the hexagonal channels of Zr(IV) porphyrinic MOF-545 hybrid framework. resulting composite fully characterized by a panel physicochemical techniques. Calculations allowed identifying localization POM vicinity Zr6 clusters and porphyrin linkers constituting MOF. material exhibits high photocatalytic activity good stability for visible-light-driven water oxidation. It thus represents rare example an all-in-one...

The targeted design and simulation of a new family zeolitic metal-organic frameworks (MOFs) based on benzenedicarboxylate (BDC) as the ligand epsilon-type Keggin polyoxometalates (POMs) building units, named here Z-POMOFs, have been performed. A key feature is use analogy between connectivity silicon in dense minerals zeolites with that POMs capped Zn(II) ions. Handling epsilon-Keggin block, selection 21 zeotype structures, together series were constructed their relative stabilities...

The Keggin-type polyoxometalate (POM) PW12O403– and the catalytic complex Cp*Rh(bpydc)Cl2 (bpydc = 2,2′-bipyridine-5,5′-dicarboxylic acid) were coimmobilized in Zr(IV) based metal organic framework UiO-67. POM is encapsulated within cavities of MOF by situ synthesis, then, Rh introduced postsynthetic linker exchange. Infrared Raman spectroscopies, 31P 13C MAS NMR, N2 adsorption isotherms, X-ray diffraction indicate structural integrity all components (POM, Rh-complex MOF) composite interest...

Polyoxometalate compounds continue to be widely studied due their relevance in various fields such as catalysis or magnetochemistry. In this article, we will focus on two topics recently developed, the functionalization of rare earth polyoxometalates by organic ligands, which has led ranging from magnetic macromolecular complexes a 3D open-framework system, and first row transition metal substituted azido allowed isolation exhibiting largest ferromagnetic exchange couplings observed date...

Organic-inorganic hybrid materials based on polyoxometalate building blocks with capping La3+ ions and bidentate oxygenated ligands have been obtained by reaction at room temperature of the [epsilon-PMo12O36(OH)4[La(H2O)4]]5+ polyoxocation glutarate (C5H6O(2)(2-)) squarate (C4O(4)(2-)) organic ligands. [epsilon-PMo12O37(OH)3[La(H2O)4(C5H6O4)0.5]4].21 H2O (1) [epsilon-PMo12O39(OH)[La(H2O)6]2-[La(H2O)5(C4O4)0.5]2].17 (2) form unprecedented 1D chains built from alternating polyoxocations...

This report reviews the state of art concerning photocatalytic degradation azo dyes using polyoxometalate-based materials. Recent developments toward polyoxometalates (POMs) and their assemblies that match multiple criteria are described. These include switchability by visible light, possibility multi-electronic photo-reduction POMs, followed reversible electron exchange with a substrate, heterogenization without loss properties finally low cost. strategy is recent shown to open up new...

Iron sandwich on a tungstate bun: Two new polyoxotungstates with paramagnetic iron(III) heteroatoms (see structure, W blue, Fe yellow, O red) possess S=15/2 and S=5 ground states. Both compounds are single-molecule magnets, the hexairon species shows large hysteresis picture) quantum tunneling effects at low temperature. Electrochemical studies indicate that these stable in solution for wide range of pH values.

The reactivity of the [α-SiW11O39]8- monovacant polyoxometalate with lanthanide has been investigated for four different trivalent rare-earth cations (Ln = NdIII, EuIII, GdIII, YbIII). crystal structures KCs4[Yb(α-SiW11O39)(H2O)2]·24H2O (1), K0.5Nd0.5[Nd2(α-SiW11O39)(H2O)11]·17H2O (2a), and Na0.5Cs4.5[Eu(α-SiW11O39)(H2O)2]·23H2O (3a) are reported. solid-state structure compound 1 consists linear wires built up anions connected by Yb3+ cations, while linkage building blocks Eu3+ centers in 3a...

Abstract Five Co II silicotungstate complexes are reported. The centrosymmetric heptanuclear compound K 20 [{(B‐β‐SiW 9 O 33 (OH))(β‐SiW 8 29 (OH) 2 )Co 3 (H O)} Co(H O) ] ⋅ 47 H ( 1 ) consists of two {(B‐β‐SiW units connected by a {CoO 4 } group. In the chiral species 7 [Co 1.5 )][(γ‐SiW 10 36 )(β‐SiW 30 (OH))Co (OH)(H ), {γ‐SiW and {β‐SiW (OH)} unit enclose mononuclear group {Co 5 fragment. trinuclear clusters present in μ ‐O atom, while ‐OH bridging connects three paramagnetic centers...

The structures of two families hybrid organic–inorganic polyoxometalates (POMs) functionalized by covalently grafted carboxylate or bisphosphonate ligands are overviewed. first family concerns the so-called POMOF materials, built from connection mixed-valent ε-Keggin type polyoxomolybdates via N-donor organic molecules coordinated to transition metal ions (ZnII, CoII, NiII) at surface POMs. simulation hypothetical zeolitic-like is presented and compared experimental ones. second gathers...

The encapsulation of polyoxometalates within the large pores Zr(iv) biphenyldicarboxylate UiO-67 metal-organic framework has been achieved, for first time, by direct solvothermal synthesis. resulting POM@UiO-67 composite materials were fully characterized XRPD, IR, MAS NMR, N2 porosimetry measurements and cyclic voltammetry.

The immobilization of polyoxometalates (POMs) near catalytic centers metal–organic frameworks (MOFs) has been reported as an advantageous strategy to boost their photocatalytic activity toward strategic reactions such CO2 reduction (CO2RR) or hydrogen evolution (HER), although the reasons for enhancement are still poorly understood. Unveiling role POM guests in reaction mechanisms is therefore a key step development next generation multicomponent materials with optimal performances. Here, we...

We report the use of Zr-based metal–organic frameworks (MOFs) MOF-545 and MOF-545(Cu) as supports to prepare catalysts with uniformly highly dispersed Ni nanoparticles (NPs) for CO2 hydrogenation into CH4. In first step, we studied MOF support under catalytic conditions using operando diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, ex situ characterizations (PXRD, XPS, TEM, EDX-element mapping), DFT calculations. showed that high-temperature undoubtedly confer a...

Six Mo dimers arranged around a central PO4 tetrahedron form the core of novel ε-Keggin polyoxocation [ε-PMo12O36(OH)4{La(H2O)4}4]5+ (see structure) capped with four {La(H2O)4}3+ units. A 31P NMR spectroscopy study shows that ion is unstable in aqueous solution, and leads to formation polyanion/polycation salt, which crystallographically characterized.

Reaction of Cu(II), [gamma-SiW10O36]8-, and N3- affords three azido polyoxotungstate complexes. Two them have been characterized by single-crystal X-ray diffraction. Complex KNaCs10[{gamma-SiW10O36Cu2(H2O)(N3)2}2].26H2O (1) is obtained as crystals in few hours after addition CsCl. This linear tetranuclear Cu(II) complex consists two [gamma-SiW10O36Cu2(H2O)(N3)2]6- units connected through W=O bridges. When the filtrate left to stand for one night, a new obtained. From both elemental analysis...

Five new materials built from polyoxotungstates and Cu(ii) ions as linkers have been synthesized by hydrothermal reactions a mixture of sodium tungstate, copper chloride bipyridine. The value the initial pH, nature heteroelement (P or Si) ligand (2,2'- and/or 4,4'-bipyridine) permit control polyoxotungstate clusters their connectivity via ions, hence dimensionality framework. A single phase has obtained with silicon at an pH 5, namely 2D material [SiW(12)O(40)][Cu(2,2'-bpy)(2)](2).10H(2)O...

Two new Cu(II) azido polyoxometalates compounds have been synthesized, and their structures were determined by X-ray crystallography. The compound Na14[SiW9O34Cu3(N3)2(OH)(H2O)]2·24H2O (1) is built from two [SiW9O34Cu3(μ1,1,3-N3)2(μ-OH)(H2O)]7- subunits where the copper centers, connected ligands one hydroxo group, form a nearly equilateral triangle. are related an inversion center via μ1,1,3-N3 in end-to-end fashion, affording hexanuclear cluster. Linkage of these fragments CuOW bonds leads...

Two new azido-bridged polyoxometalate compounds were synthesized in acetonitrile/methanol media and their molecular structures have been determined by X-ray crystallography. The [[(gamma-SiW10O36)Mn2(OH)2(N3)(0.5)(H2O)(0.5)]2(mu-1,3-N3)](10-) (1 a) tetranuclear Mn(III) complex, which an end-to-end N3- ligand acts as a linker between two [(gamma-SiW10O36)Mn2(OH)2]4- units, represents the first manganese-azido polyoxometalate. magnetic properties studied considering spin Hamiltonian H =...

Unprecedented molecular and bidimensional compounds based on monovacant polyoxometalates capped by heterometallic 3d–4f {LnCu3(OH)3O} (Ln = La, Gd, Eu) cubane fragments have been characterized their magnetic properties investigated.

Abstract A POM to remember : Hexanuclear Fe III polyoxometalate (POM) single‐molecule magnets (see structure) can be noncovalently assembled on the surface of single‐wall carbon nanotubes. Complementary characterization techniques TEM image and magnetic hysteresis loops) demonstrate integrity bistability individual molecules, which could used construct memory devices. magnified