Organic–inorganic hybrid oxides: Structure and magnetic properties of [{Cu(terpy)}2Mo6O17(H2O)(O3PCH2NH2CH2PO3)2] · H2O,a bimetallic oxide constructed from novel {Mo6O17(H2O)(O3PCH2NH2CH2PO3)2}4− clusters

The hydrothermal reaction of MoO₃, CuSO₄ · 5H₂O, 2,2′:6′:2″-terpyridine (terpy) and bis-N,N-(methylphosphonic acid) amine (H₂O₃PCH₂NHCH₂PO₃H₂) provided blue crystals of the bimetallic oxide [{Cu(terpy)}₂Mo₆O₁₇(H₂O)(O₃PCH₂NH₂CH₂PO₃)₂] · H₂O (1 · H₂O). The three-dimensional structure of 1 is constructed from {Mo₆O₁₇(H₂O)(O₃PCH₂NH₂CH₂PO₃)₂}⁴⁻ clusters linked through {Cu(terpy)}²⁺ subunits. The cluster consists of three pairs of edge-sharing {MoO₆} octahedra linked through corner-sharing interactions into a {Mo₆O₆} ring. One phosphonate ligand spans the diameter of the ring, bridging four molybdenum sites and leaving at a pendant {PO} group at each terminus. The second diphosphonate ligand exploits one {–PO₃} unit to cap the hexamolybdate ring and bridge all six molybdenum sites while the second {–PO₃} terminus bridges two molybdenum sites, leaving a pendant {PO} unit. Crystal data: C₃₄H₄₅Cu₂Mo₆N₈O₃₅P₄: monoclinic, P2₁/n, a = 11.9431(7) Å, b = 17.382(1) Å, c = 27.524(2) Å, β = 90.429(1)°, V = 5713.7(6) Å³, Z = 4, D_calc = 2.270 g cm⁻³, R₁ = 0.0466.     

A new dual luminescent pillared cerium(IV)sulfate–diphosphonate

A new pillared cerium(IV) sulfate–diphosphonate with formula Ce₂(2H₂O)[(O₃PCH₂)–NC₁₀H₁₈N–(CH₂PO₃)(SO₄)₂] · 6H₂O has been hydrothermally synthesized and its structure has been solved ab initio from laboratory X-ray powder diffraction data.The luminescent and thermal properties of this compound have been preliminarily studied and the encouraging results place it in the field of functional hybrid materials.     

Coordination of the carboxylate of the functionalized Strandberg anion in a three dimensional covalence framework

[H₃O]₂[{Cu₆(bipy)₁₀(H₂O)₄}{Cu₂(bipy)₂(H₂O)₄}{(HO₂CC₂H₄PO₃)Mo₅O₁₅(O₂CC₂H₄PO₃)}₂{(HO₂CC₂H₄PO₃)₂Mo₅O₁₅}₂]·30H₂O (1) was obtained from aqua solution. In 1 the linkage between bipy and Cu^2 + ions creates a layer with rhombus channel and an isolated chain. [(HOOCC₂H₄PO₃)₂Mo₅O₁₅]^4 – anions act as tridentate and tetradentate ligands, connecting the layers and the chains into a three dimensional covalent framework through the oxygen atoms of carboxylate groups and of MoO₆ octahedra.     

Synthesis and crystal structure of hexacerium(IV) cluster-containing Keggin polyoxometalate trimer

A novel hexacerium(IV) cluster-containing polyoxometalate (POM), K₁₈[{Ce₆(μ₃-O)₄(μ₃-OH)₄(OAc)₂}(A-α-SiW₉O₃₄)₂(α-SiW₁₁O₃₉)]·37H₂O (K₁₈Ce₆-POM), was unexpectedly obtained by a reaction of the potassium salt of open-Dawson POM, K₁₃[{K(H₂O)₃}₂{K(H₂O)₂}α,α-Si₂W₁₈O₆₆]·19H₂O (K-open POM), with (NH₄)₂[Ce(NO₃)₆], in a 0.5 M KOAc/HOAc buffer solution (pH 4.8) at 80 °C, and unequivocally characterized by X-ray crystallography, ¹H, ¹³C, and ²⁹Si NMR spectroscopy, FTIR spectroscopy, complete elemental analysis, and TG/DTA. X-ray crystallography revealed that the monolacunary Keggin unit, [α-SiW₁₁O₃₉]^8 −, and the two trilacunary Keggin units, [A-α-SiW₉O₃₄]^10 −, are connected by a central Ce₆-oxo/hydroxide cluster moiety, [Ce₆(μ₃-O)₄(μ₃-OH)₄(OAc)₂]^10 +, to form a trimeric Keggin polyanion, [{Ce₆(μ₃-O)₄(μ₃-OH)₄(OAc)₂}(A-α-SiW₉O₃₄)₂(α-SiW₁₁O₃₉)]^18 − (Ce₆-POM). ¹H, ¹³C, and ²⁹Si NMR spectra in D₂O suggested that the Ce₆-POM was obtained as a single species and its molecular structure was maintained in solution.     

Decavanadate with a novel coordination complex: Synthesis and characterization of (NH4)2[Ni(H2O)5(NH3)]2(V10O28)·4H2O

A new compound (NH₄)₂[Ni(H₂O)₅(NH₃)]₂[V₁₀O₂₈]·4H₂O (1) containing a {V₁₀O₂₈} ⁶⁻ anionic cluster and a novel complex cation, [Ni(H₂O)₅(NH₃)]^2 +, has been synthesized and fully characterized by single crystal X-ray crystallography, spectroscopy and thermogravimetric analysis. The presence of the ammonia ligand in the complex cation in 1 was established unambiguously by X-ray crystallography and variable temperature (200–400 °C) thermogravimetric analyses in combination with FTIR spectroscopic studies. The formation of the novel complex species {Ni(H₂O)₅(NH₃)}^2 + during the synthesis of 1 can be rationalized in terms of ligand substitution involving {Ni(H₂O)₆}^2 +.     

Squarato-metal(II) complexes: Part 6. Synthesis,structure and magnetic characterization of an usual squarate-based 1D copper(II) coordination polymer composed of hexanuclear entities and a trinucleating ligand scaffold

The reaction of the polynucleating ligand 1,3,5-tris[bis(2-pyridylmethyl)aminomethyl]benzene (L^TDPA) with Cu(ClO₄)₂ · 6H₂O afforded the trinuclear complex [Cu₃(T^TDPA)(H₂O)₇](ClO₄)₆ · 5H₂O (1). When the reaction was performed in the presence of the squarate dianion, C₄O₄^2-, the compound {[Cu₆(L^TDPA)₂(μ_1,3-C₄O₄)₃](ClO₄)₆ · 12H₂O}_n (2) was obtained. Both compounds have been characterized by X-ray crystallography, showing a trinuclear and a 1D polymeric structures for 1 and 2, respectively. Complex 2 is composed of unusual hexametallic building blocks. Magnetic susceptibility measurements (SQUID) reveal essentially uncoupled copper(II) ions in complex 1, whereas complex 2 shows weak antiferromagnetic coupling via the squarato bridges within magnetically isolated dicopper(II) subunits of the 1D chain.     

Binuclear cyano-bridged complex derived from [MnIII(salpn)] and [FeIII(CN)6]: Synthesis,structure and magnetic properties

The reaction of the neutral [Mn(salpn)C(CN)₃(H₂O)] (salpn^2 − = N,N^′-1,3-propylenebis(salicylideneiminato) dianion) with [Fe^III(CN)₆]^3 − in the presence of strong oxidizer (NH₄)₂S₂O₈ yields a binuclear anion complex [NH₃CH₂CH₂CH₂NH₃]^2 +{[Mn^III(salpn)(H₂O)][Fe^III(CN)₆]}^2 − (1). Its structure, DC and AC susceptibility have been studied. Frequency dependence of the AC susceptibility characteristic for single-molecule magnets has been found.     

A three-dimensional zincic molybdenum (V) phosphate with helical channel: Synthesis,structure, and electrochemical properties

A new reduced zincic molybdophosphate, (H₂bpp)₃[Zn₃Mo₁₂^VO₂₄(OH)₆(H₂O)₂(HPO₄)₆(PO₄)₂]·2H₂O 1 (bpp = 1,3-bis(4-pyridyl)propane) has been hydrothermally synthesized and characterized by elemental analysis, IR, TG, and single-crystal X-ray diffraction. Compound 1 crystallizes in the tetragonal space group I 41/a c d with a = 31.8033(4) Å, b = 31.8033(4) Å, c = 34.5593(8) Å, V = 34955.0(10) ų, and Z = 16 and exhibits a 4,6-connected 3-D framework with (3².8⁴)(3⁴.4².8³.9⁵.10) topology. The basic building blocks of [Zn(2)(Mo₆P₄)₂] are linked through [Zn(3)O₆] octahedra and [Zn(1)O₄] tetrahedra to construct 1-D chains along four different directions. Such 1-D chains are further connected by [Zn(1)O₄]²⁺ linkers to form a 3-D intricate framework with helical channels occupied by protonated bpp and water molecules. Additionally, the electrochemical property of the 1-CPE has been studied in detail.     

Synthesis and crystal structures of two new inorganic–organic hybrid polyoxomolybdate complexes: [Himi]4[{Co(imi)2(H2O)2}Mo7O24] · 4H2O and [Zn(imi)4]2[(imi)2Mo8O26] · 6H2O

The two new inorganic–organic hybrid polyoxomolybdate complexes [Himi]₄[{Co(imi)₂(H₂O)₂}Mo₇O₂₄] · 4H₂O (1) and [Zn(imi)₄]₂[(imi)₂Mo₈O₂₆] · 6H₂O (2) (imi = imidazole) have been prepared by conventional aqueous solution synthesis. Compound 1 consists of heptamolybdate anions [Mo₇O₂₄]⁶⁻ covalently linked by [CoN₂O₄]²⁺ octahedra into one-dimensional zigzag-shaped chains. The zigzag-shaped chains are further linked together via the hydrogen-bonding interactions to form a 2D supramolecular framework. Compound 2 is build up of an imidazole-coordinated octamolybdate anion, two imidazole coordinating zinc cations and lattice water molecules to form a three-dimensional framework via complex hydrogen-bonding.     

Two highly connected frameworks and one polythreading architecture based on multidentate N-donor ligands: Syntheses,structures, characterizations and photoluminescent properties

Three coordination polymers based on multidentate N-donor ligands and polycarboxylate anions, namely, [Co₃(4,4′-tmbpt)₄(btc)₂]·9.5H₂O (1), [Ag₄(4,4′-tmbpt)(btec)(H₂O)₂]·H₂O (2) and [Zn(4,4′-tmbpt)(btec)_0.5(H₂O)]·0.5H₂O (3) (4,4′-tmbpt = 1-((1H-1,2,4-triazol-1-yl)methyl)-3,5-bis(4-pyridyl)-1,2,4-triazole, H₃btc = 1,3,5-benzenetricarboxylic acid, and H₄btec = 1,2,4,5-benzenetetracarboxylic acid) have been prepared under hydrothermal condition. Compound 1 displays a 3D (3,6,8)-connected framework with (4·6²)(4⁴·6¹⁰·8)(4¹⁴·6¹²·8²) topology. Compound 2 is a 3D (4,5,8)-connected framework with (4³·6²·8)(4³·6⁵·8²)(4⁸·6²)(4¹⁰·6¹⁰·8⁸) topology. Compound 3 exhibits a 2D → 3D polythreading architecture. The photoluminescent spectra indicate that at room temperature, compounds 2 and 3 emit green and blue luminescence, respectively.     

A new carboxyethyltin functionalized sandwich-type tungstoarsenate: Synthesis,catalytic activity and corrosion inhibition behavior for carbon steel

A new Keggin sandwich-type polyoxometalate (POM) estertin derivative Na₈K₆[{Sn(CH₂)₂COO}₂(B-α-AsW₉O₃₃)₂]·27H₂O (compound 1) has been successfully synthesized from K₁₄[As₂W₁₉O₆₇(H₂O)]·nH₂O ({As₂W₁₉}) and Cl₃SnCH₂CH₂COOCH₃, and characterized by physico-chemical and spectroscopic methods. The corrosion inhibition behavior of compound 1 for carbon steel in 0.4 mol L^− 1 NaAc-HAc buffer solution with pH = 6.0 was evaluated by polarization curves and electrochemical impedance spectroscopy (EIS), and its catalytic activity towards the oxidation of cyclohexanol to cyclohexanone was also studied.     

A MnII5 tetragonal pyramid stabilized by p-tert-butylcalix[8]arene: Synthesis,structure and magnetic property

A compound, [Mn₅(H₄C8A)(OH)₂(C₃H₆NO₂)(DMF)₅(CH₃O)_1.5(HCO₂) (C₂H₃O₂)_0.5]·2DMF·CH₃OH (1) (H₈C8A = p-tert-butylcalix[8]arene, DMF = N,N′-dimethylformamide), was synthesized by the solvothermal method in the mixed CH₃OH/DMF (1:1) solvent. Compound 1 is featured with a tetragonal pyramid-like Mn^II₅ cluster encircled within a calix[8]arene molecule with a ‘pleated loop’ conformation. Magnetic study indicates that the Mn^II centers exhibit antiferromagnetic interactions.     

A novel polyoxometalate-based metal-organic compound constructed from an unprecedented [Ag8(Hpyttz)4(H2pyttz)2] cluster and an in-situ [VW12O40]3 − anion

A novel polyoxometalate (POM)-based metal-organic compound constructed from a multinuclear Ag^I cluster and Keggin-type [VW₁₂O₄₀]^3 − anion, [Ag₄(Hpyttz)₂(H₂pyttz)][HVW₁₂O₄₀]·3H₂O (1) (H₂pyttz = 5′-(pyridin-4-yl)-1H,2′H-3,3′-bi(1,2,4-triazole), was hydrothermally synthesized and characterized by IR spectroscopy, TG analysis, powder and single-crystal X-ray diffraction. In compound 1, [VW₁₂O₄₀]^3 − (VW₁₂) was in-situ transformed from [SiW₁₂O₄₀]^4 − anion. Eight Ag^I ions were connected by six Hpyttz/H₂pyttz ligands with three coordination modes forming an unprecedented [Ag₈(Hpyttz)₄(H₂pyttz)₂] cluster, which connected with six VW₁₂ anions to construct a 2-D double-layer (3,6)-connected network with {4³}₂{4⁶.6⁶.8³} topology. Moreover, the photocatalytic activity of 1 has been investigated.     

A novel 3D network structure constructed from centrosymmetric sodium-phosphomolybdate bonding by sodium and zinc atoms

A novel molybdenum (V) phosphate compound, (NH₃CH₂CH₂NH₃) (NH₃CH₂CH₂NH₂)₄Zn₂Na(2){Na(1)[Mo₆O₁₆(HPO₄)₃(PO₄)(OH)₃(H₂O)]₂} · 3 H₂O was synthesized hydrothermally and characterized by elemental analysis, IR, TG-DTA, DRS, BET and single crystal X-ray diffraction. In this compound, the centrosymmetric Na(1)[Mo₆P₄]₂ clusters are linked by Na(2) to produce one-dimensional chains along b axis. Then such 1D chains are further connected by [ZnO₄] tetrahedra to construct a three-dimensional (3D) framework with channels occupied by protonated ethylenediamine ions and the water molecules. Photocatalytic reduction of Rhodamine B (RB) in a liquid-solid system shows that the title compound has high photocatalytic activity.     

An uncommon 3D Co5-cluster-based metal-organic framework: Synthesis,structure and magnetism

A highly connected metal–organic framework (MOF), namely, [Co₅(μ₃-OH)₂(iapt)₄(4,4′-bipy)_0.5(H₂O)·CH₃CN·3H₂O] (1) (H₂iapt = 5-aminoisophthalic acid and 4,4′-bipy = 4,4′-bipyridine), is reported. 1 shows a complicated pentanodal 4,4,4,4,13-c 3D net with (4³)(4³)(4³)(4³)(4²⁰·5¹⁴·6²³·7⁸·8¹³) topology based on an uncommon Co₅ cluster. The magnetic analysis reveals antiferromagnetic interactions in 1, and both the local spin–orbit coupling of octahedral Co(II) ions and the antiferromagnetic interactions are the primary factors in the magnetic behaviour.     

A new (4,8)-connected topological MOF as potential drug delivery

A new compound of (NH₂(CH₃)₂[Zn₃(L)₂·3.5DMF]) (1) (H₄L = 1,1′,4′,1″,4″,1‴-quaterphenyl-3,5,3‴,5‴-tetracarboxylic acid 1,3,5-benzenetrisbenzoate) was synthesized and characterized. The coordination polymer shows an unusual 4,8-connected 3D net with (4⁶)₂(4¹²·6¹²·8⁴) topology. The incorporation of the drug 5-fluorouracil (5-FU) into the desolvated 1 was around 22.5 wt.% per gram of dehydrated 1. 5-Fu is released in a highly controlled and progressive fashion with 92% of the drug released after 120 h. The result from this work provides a new avenue for MOF to be used as potential drug delivery.     

Two organic–inorganic hybrid materials based on the penta-nuclear {MMn4} (M = W and Mo) heterometallic clusters and Schiff-base ligands

Two organic–inorganic hybrid compounds with the formula {[Mn^III(Salen)(H₂O)]₄MoO₄}·Cl₂·16H₂O (1) and {[Mn^III(Salen)(H₂O)]₄WO₄}·(CH₃COO)₂·11H₂O (2) (Salen = Di-[2-hydroxyl-3-methoxyl-benzaldehyde] ethylenediamine) have been synthesized and structurally characterized by IR, UV–vis spectroscopy, TG analysis and single crystal X-ray diffraction. Structural analysis revealed that compounds 1 and 2 consist of a [MoO₄]^2 − or [WO₄]^2 − building unit and four {[Mn^III(Salen)(H₂O)]⁺ metal–organic moieties, respectively. In the crystal structure, the [MoO₄]^2 − or [WO₄]^2 − tetrahedra coordinated with four Mn^III ions, resulting in the penta-nuclear heterometallic tetrahedra cluster compounds, which were rarely observed in the Mn-Salen system. Magnetic study revealed that there was antiferromagnetic coupling in the two compounds.     

A 3D heterometallic Pb(II)-Na(I) coordination polymer as a sensitive and selective fluorescent sensor for detecting Fe3 +

A Pb(II)-Na(I) coordination polymer, {[Pb₃NaL₃](Me₂NH₂)₂(C₂H₅OH)_1.5(H₂O)_10.5}_n (1) (H₃L = 4,4′,4″-s-triazine-2,4,6-triyl-tribenzoic acid), was synthesized under solvothermal condition. This structure crystallizes in the orthorhombic system and shows a 3D pillar-layer network. Topologically, it shows complicate (3,4,5,6,7)-connected net with Schläfli symbol of (4²·6⁸·8⁹·10²)(4³·6²·8)₂(4³·6⁶·8)₂(4⁸·6⁶·8)(6³). Luminescent investigations reveal that 1 can detect Fe^3 + with relative high sensitivity and selectivity, and show broad linear range of 0–1000 μM, as well as low detection limits of 8.65 nM for Fe^3 +.     

A new polynuclear Fe(III) cluster based on inorganic O-donor polyoxometalate and organic N-donor ligands

A new polynuclear Fe(III) cluster based on both inorganic O-donor polyoxometalate ligand and organic N-donor ligand hexamethylenetetramine (hmta), Na₉(CH₃-hmta)₄ (hmta)₂[{Fe_10?xW_xH_15?3xO₁₅(hmta)₂}(P₂W₁₃O₅₁)₂] · ～70H₂O (x = 0.18) (1), has been synthesized and structurally characterized, exhibiting good electrocatalytic properties to reduce the nitrites.     

Synthesis,crystal structure,characterization and magnetic property of a new organophosphonate-based polyoxovanadate

A novel organophosphonate-based polyoxovanadate, Cs_1·5Na_3.5[H{V₃(H₂O)O₃}{O₃PC- (OH)(CH₃)PO₃}₃]·15H₂O (1) has been synthesized and further investigated by single-crystal X-ray diffraction analysis, IR spectrum, UV–vis spectroscopy, X-ray powder diffraction, thermogravimetric analysis and X-ray photoelectron spectroscopy. Single-crystal X-ray analysis reveals that compound 1 crystallizes in the triclinic space group P-1 with a = 9.506(3) Å, b = 15.150(5) Å, c = 17.915(6) Å, V = 2437.9(14) ų and Z = 2. Compound 1 exhibits a ring-shaped cluster with three branches of the 1-hydroxyethane 1, 1-diphosphonic acid [HEDP = H₂O₃P(OH)C(CH₃)PO₃H₂] ligands. Furthermore, the magnetic property of compound 1 has also been studied.