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.     

Structure and magnetic properties of a novel branch-like one-dimensional cyano-bridged assembly [Cu(L)]3[Fe(CN)6]2·8H2O (L = 6,13-dimethyl-6-nitro-1,4,8,11-tetraazabicyclo[11.1.1]pentadecane)

The one-dimensional coordination polymer like fern branch, [Cu^II(L)]₃[Fe^III(CN)₆]₂·8H₂O (1), which is linked by azamacrocyclic copper(II) complex and iron(III) hexacyanide, has been synthesized and characterized by single crystal X-ray crystallography and magnetic susceptibility measurement (L = 6,13-dimethyl-6-nitro-1,4,8,11-tetraazabicyclo[11.1.1]pentadecane). Compound 1 shows a weak ferromagnetic coupling between the copper(II) and low spin iron(III) ions in the one-dimensional chain structure.     

Synthesis,structure and magnetic properties of a copper molybdate hybrid inorganic/organic solid with a novel 10-connected three-dimensional network topology

Hydrothermal reaction of CuCl₂, MoO₃, and 4,4′-dipyridylketone (4,4′-dpk) afforded green crystals of the mixed metal oxide phase {[Cu₂(MoO₄)₂(4,4′-dpk)(H₂O)]·H₂O}_n (1). According to single-crystal X-ray diffraction, {Cu₂O₂} dimers link into 1-D {Cu₂O₂(μ-H₂O)}_n chains via bridging aqua ligands. These chains form [Cu₂(MoO₄)₂(H₂O)]_n slabs via linkage through tetrahedral molybdate anions. In turn, the copper molybdate slabs are pillared through tethering 4,4′-dpk ligands into a 10-connected three-dimensional lattice with an unprecedented 3¹²4³⁰5²6 topology. Variable temperature magnetic data above 140 K were fit to the Curie–Weiss law, with C = 0.17 cm³ K/mol Cu and Θ = 70 K, indicating likely ferromagnetic coupling within the dinuclear kernels of 1; low temperature data points towards the possibility of interdimer antiferromagnetic interactions.     

A predesigned 1D chain of alternating di-μ1,1-azido bridged dinuclear Ni(II) and pyrazine: Synthesis,structure and magnetic properties

A new Ni(II) complex, [Ni₂(L)₂(μ_1,1-N₃)₂(pyz)]_n (1) (where pyz = pyrazine) has been synthesized using a dinuclear di-μ_1,1-azido bridged Ni₂ molecular building block derived from a tridentate NNO donor Schiff base ligand, HL (2-[(3-methylamino-propylimino)-methyl]-phenol) along with pyrazine as spacer. Single crystal X-ray analysis shows that complex 1 is a 1D chain in which dimeric Ni₂ units [Ni₂L₂(N₃)₂] are linked to each other by the bridging pyrazine ligand. Variable-temperature magnetic susceptibility studies indicate the presence of moderate ferromagnetic exchange coupling in complex 1 with J value of 53.54 cm^− 1.     

A new complex based on chelate copper coordination with divacant polyanion ligand [γ-PW10O36]7−

A new complex based on decatungstophosphate and chelated copper atoms, [Hen][Cu(en)₂(H₂O)]₂ · {[Cu(en)₂(H₂O)] · [γ-PW₁₀O₃₆]} · 9H₂O (1) (en = ethylenediamine) has been synthesized by conventional methods and characterized by single crystal X-ray diffraction, IR spectra and electronic spectra. The structure analysis of 1 indicates that the complex contains a divacant polyanion [γ-PW₁₀O₃₆]⁷⁻ connected with a chelated copper atom. Magnetic susceptibility measurement for 1 in the temperature range 2–300 K reveals the occurrence of intermolecular antiferromagnetic interactions between chelate copper (II) complexes at lower temperature.     

One-dimensional macrocyclic zinc(II) coordination polymer containing an unusual bis-monodentate oxalate bridge

A new zinc(II) complex, {[Zn(L1)(oxalate)] · 3.5H₂O}_n (1) (L = 5,16-dimethyl-2,6,13,17-tetraazatricyclo[16.4.0^1,18.0^{7, 12}]docosane) has been prepared and characterized by single crystal X-ray structure determination. In 1 the rigidity and steric hindrance of the macrocycle L1 causes the bridging oxalate ligand to coordinate to the zinc(II) ions in an unusual twisted bis-monodentate coordination (1,1′-bicoordination) mode.     

An organic–inorganic hybrid uranyl nicotinate molybdate polymer and its fluorescent property

A uranyl nicotinate molybdate polymer [UO₂(nicot)(MoO₃OH)]_n (Hnicot = nicotinic acid, NC₅H₄CO₂H) was synthesized by the hydrothermal reaction of uranyl nitrate [UO₂(NO₃)₂ · 6H₂O], phosphomolybolic acid (H₃PMo₁₂O₄₀) and nicotinic acid. Its crystal structure and fluorescent property were measured. The results show that the crystal packs in the 1D chains of uranyl molybdates with strong fluorescence at the range of 470–520 nm.     

Two new polyoxometalate-based metal-organic complexes constructed from two in-situ transformed ligands through different ways

Two new Keggin-type polyoxometalates-based metal–organic complexes: [Ag₃(L1)₃(PMo₁₂O₄₀)]·3H₂O (1) and Ag₄(L2)₂(HL2)(PW₁₂O₄₀)Na₂(μ-OH)]·1.5H₂O (2) (L1 = 1.2.4-triazole, HL2 = 4-amino-1,2,4-triazole) have been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction analyses, IR spectra and powder X-ray diffraction analyses. In compound 1, the [Ag₆(L1)₆] crown-shaped ring was clamped by two [PMo₁₂O₄₀]^3 − polyanions, forming a sandwich-like [Ag₆(L1)₆(PMo₁₂O₄₀)₂] unit, which was extended to a 1D supramolecular chain through hydrogen bonding interaction. Compound 2 is a 3D metal–organic framework containing the [Ag₆(L2)₄(HL2)₂] crown-shaped ring and 1D [Na₂(PW₁₂O₄₀)(μ-OH)]_n inorganic chains, which represents a novel (3,3,4,6,10-c)-connected 3D topological framework. The L1 and L2 ligands were in-situ transformed from two different N-heterocyclic amide ligands through different ways, respectively. In addition, the electrocatalytic and photocatalytic activities of the title compounds have been studied.     

First hexanuclear manganese(II) μ6-Cl centered carboxylate anion: Synthesis,structure and magnetic properties

Reaction of manganese(II) polymer [Mn₅Cl(OH)(Piv)₈(MeCN)(HPiv)(H₂O)]_n (1, HPiv is pivalic acid) and 2-benzoylpyridine (L) in MeCN produces the ionic complex [Mn₃(Piv)₅L₂(MeCN)]⁺[Mn₆Cl(Piv)₁₂]⁻ · MeCN (3) containing the unusual hexanuclear {Mn₆(μ₆-Cl)} anion. An analogous anion was also observed in the complex [Mn₆Cl(Piv)₁₂]⁻(NEt₄)⁺ · 5MeCN (4) prepared by the reaction of the polymer [Mn(Piv)₂(EtOH)]_n (2) with NEt₄Cl in MeCN. Complexes 3 and 4 were characterized by the X-ray diffraction and magnetic susceptibility.     

Synthesis,structure, and luminescence of a novel lead(II) coordination polymer with 1,2-phenylenediacetic acid

A coordination polymer [Pb₂(phda)₂]_n (H₂phda = 1,2-phenylenediacetic acid) was synthesized and characterized by single crystal X-ray diffraction. The complex has a (6, 6)-connected 2D framework with topology of (4¹⁵), in which Pb²⁺…π interaction is observed. The 2D framework is further assembled by C–H…π interactions, resulting in a 3D supramolecular network. The fluorescence of the complex is assigned to the intraligand π^?–π transition and the ligand-to-metal charge transfer.     

[Tl2(μ-Htdp)2(μ-H2O)]n (H2tdp = 4,4′-thiodiphenol) – A one-dimensional thallium(I) coordination polymer with a large tetranuclear metallacycle: Thermal,emission and structural studies

[Tl₂(μ-Htdp)₂(μ-H₂O)]_n (H₂tdp = 4,4′-thiodiphenol) (1), a new rarely reported Tl^I one-dimensional coordination polymer with a large tetranuclear metallacycle, has been synthesized, characterized by elemental analysis and IR spectroscopy and its structure determined by single-crystal X-ray diffraction. The thermal stability of compound 1 was studied by thermal gravimetric (TG) and differential thermal analyses (DTA). The single crystal X-ray analysis of compound 1 shows that the complex consists of horseshoe-shaped (μ-Htdp)Tl(μ-H₂O)Tl(μ-Htdp) subunits. Solid-state luminescent spectra of the ligand H₂tdp and compound 1 indicate emission band with the maximum intensity at 475 and 465 nm upon excitation at 300 nm, respectively.     

Synthesis,crystal structures and properties of two Pd(II) and Pt(II) complexes involving 3,5-diphenylpyrazole and NO2 donor ligands

A pyrazolate bridged binuclear Pd(II) complex [Pd₂(μ-dppz)₂(Hida)₂] · CH₃OH · 2H₂O (1) (dppz = 3,5-diphenylpyrazolate) with monoprotonated iminodiacetate (Hida) and a mononuclear Pt(II) complex containing Hdppz and 2,6-pyridinedicarboxylate (2,6-dipic) [Pt(Hdppz)(2,6-dipic)] · CH₃OH (2) have been synthesized and characterized by elemental analysis, ¹H NMR, ESI-MS and single crystal X-ray diffraction studies. The molecular packing for 1 shows a 2D network while that for 2 constitutes a left-handed 1D helix. Moderate luminescence property and antimicrobial activity against Bacillus subtilis have been noted for both.     

A pillar-layered-like metal-organic framework built from dinuclear cobalt chain and a V-shaped bis-pyridyl ligand with different coordination modes

Solvothermal assembly of Co^2 + ion, a V-shaped bis-pyridyl ligand with two different coordination modes and a tripodal multicarboxylate ligand yields a complicated 3D metal-organic framework, namely [Co(OPY)_1.5(Hbtc)]_n (1), [OPY = 4,4′-(oxybis(4,1-phenylene))dipyridine and H₃btc = trimesic acid]. The compound 1 has been characterized by IR, elemental analysis, single crystal X-ray diffraction, XRD and TG analysis. Magnetic measurements performed on 1 indicate the occurrence of weak antiferromagnetic coupling between the neighboring Co^2 + ions. In addition, the compound shows high thermal stability.     

A new 3D coordination framework with helical chains in mixed ligands system: Preparation,crystal structure and magnetic property

A new 3D coordination polymer [Ni₂(L)₂(bpp)₂(μ₂-H₂O)] (1) (H₂L = 2,4-dibenzoylisophthalic acid and bpp = 1,3-bis(4-pyridyl)propane) has been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectra, and thermogravimetric analysis. Further, it was determined by single crystal X-ray diffraction analysis. Compound 1 is a 3D network with (3⁶·4⁸·5⁷) topology, which comprises of two kinds of helical chains. Additionally, compound 1 shows ferromagnetic interactions among metal ions.     

Synthesis,structures, luminescent and magnetic properties of four coordination polymers based on biphenyl-2,4′,5-tricarboxylic acid and different N-donor ligands

Four new coordination polymers [Zn(HL)(bibp)]_n (1: H₃L = biphenyl-2,4′,5-tricarboxylic acid, bibp = 4,4′-bis(imidazolyl)biphenyl), [Co(HL)(bibp)]_n (2), [Co(HL)(bib)]_n·4nH₂O (3: bib = 1,4-bis(1-imidazoly)-benzene), [Co_1.5(L)(bib)_1.5(H₂O)]_n·3nH₂O (4), have been synthesized under solvo/hydrothermal conditions, and have been fully characterized by single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), IR spectra, elemental analysis and thermogravimetric analysis (TGA). Structural analyses reveal that both 1 and 2 display a 4-fold interpenetrated framework. Complex 3 possesses a 2D (4,4) network. Complex 4 exhibits a 3D framework with the point symbol of {3²·4·6⁷}₂{3²·6¹⁰·7²·8}. Moreover, photoluminescence properties of 1 and magnetic properties of 2–4 have also been studied in detail.     

Luminescent monomeric and polymeric cuprous halide complexes with 1,2-bis(3,5-dimethylpyrazol-1-ylmethyl)-benzene as ligand

Reaction of cuprous bromide with equimolar amounts of 1,2-bis(3,5-dimethylpyrazol-1-ylmethyl)-benzene (dpb) affords a mononuclear three-coordinated complex [CuBr(dpb)] (F2) with dpb acting as a chelating ligand. In contrast, using cuprous iodide instead under the same conditions gives the polymeric compound [Cu₂I₂(dpb)]_n (F1) which contains double-bridging iodine atoms. The complexes were characterized by element analysis and ¹H NMR spectroscopy, and the crystal structures were determined by single-crystal X-ray diffraction methods. The Cu(I) complexes are luminescent in the solid state at ambient temperature. Intense orange emission for complex F1 is observed, with maxima at 593 nm, probably ascribed to a combination of a halide-to-metal charge transfer and copper-centered d → s, p transitions. F2 exhibits a blue photoluminescence, with emission maximum at 515 nm, assigned to metal-to-ligand charge-transfer excited states, probably mixed with some halide-to-ligand characters.     

Synthesis of enantiomers of mononuclear Ru(II) complexes with 10,13-diaryl substituted dppz ligands

An array of enantiomerically pure mononuclcear [Ru(bpy)₂(dppz)]^2 + derivatives with 10,13-diaryl substituted dppz ligand has been synthesized and characterized (bpy = bipyridine, dppz = pyrido-[3,2-a:2′,3′-c]phenazine). These new complexes exhibit substantially similar absorption spectra, resembling the parent complex [Ru(bpy)₂(dppz)]^2 +, and the enantiomerically pure analogues show the similar CD spectra in buffer solution despite the structural difference.     

Thermal dehydration of Y(TFA)3(H2O)3: Synthesis and molecular structures of [Y(μ,η1:η1-TFA)3(THF)(H2O)]1∞ · THF and [Y4(μ3-OH)4(μ,η1:η1-TFA)6(η1-TFA)(η2-TFA)(THF)3(DMSO)(H2O)] · 6THF (TFA = trifluoroacetate)

In order to obtain a better anhydrous precursor for various applications in materials science and catalysis, thermal dehydration reactions of Y(TFA)₃(H₂O)₃ (TFA = trifluoroacetate) (A) were investigated. Thermal treatment of A at different temperatures under vacuum (5 × 10^?2 mm) for several hours failed to give totally anhydrous yttrium trifluoroacetate (as indicated by IR). Two different complexes, a partially dehydrated [Y(μ,η¹:η¹-TFA)₃(THF)(H₂O)]_1∞·THF (1) and a partially hydrolyzed [Y₄(μ₃-OH)₄(μ,η¹:η¹-TFA)₆(η¹-TFA)(η²-TFA)(THF)₃(DMSO)(H₂O)] · 6THF (2), were obtained with good and moderate yield, respectively, by crystallization of two different thermally treated batches of A from THF (or THF + DMSO) at room temperature. More efficient dehydration of A could be achieved at 200 °C in a furnace, the obtained anhydrous yttrium tris-trifluoroacetate giving Y(TFA)₃(THF)₂ (3) on crystallization from THF. All the products were characterized by elemental analyses, FT-IR and ¹H NMR spectroscopy as well as thermo-gravimetric analysis. In addition, single crystal X-ray structures are reported for 1 and 2, which show either a terminal (η¹ and η²) or bridging (μ,η¹:η¹) bonding behavior of the TFA ligand.     

Two novel cadmium(II) coordination polymers based on bis-functionalized ligand 4′-(4-carboxyphenyl)-2, 2′:6′, 2″-terpyridine

Two novel cadmium(II) coordination polymers [Cd(cptpy)₂]_n·nH₂O (1) with a 1D double chain structure and [Cd₂(cptpy)₂(ox)]_n·2.5nH₂O (2) with an interesting 3-connected uninodal six-fold interpenetrating ths network (Hcptpy = 4′-(4-carboxyphenyl)-2,2′:6′,2″-terpyridine, H₂ox = oxalic acid) have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, single crystal X-ray diffraction and fluorescence spectra.     

Copper–cobalt heterobimetallic ceramic oxide thin film deposition: Synthesis,characterization and application of precursor

Thin films of halide free Cu–Co mixed metal oxide have been prepared at 390 °C from the heterobimetallic complex Co₄(THF)₄(TFA)₈(μ-OH)₂Cu₂(dmae)₂ · 0.5C₇H₈ (1) [dmae = N,N-dimethylaminoethanol ((CH₃)₂NCH₂CH₂O⁻), TFA = triflouroacetate (CF₃COO⁻), THF = tetrahydrofurane (C₄H₈O)] which was prepared by the reaction of [Cu(dmae)Cl]₄ and Co(TFA)₂ · 4H₂O. The precursor was characterized for its melting point, elemental composition, FTIR and X-ray single crystal structure determination. Thin films grown on glass substrate by using AACVD out of complex 1 were characterized by XRD and SEM. TGA and AACVD experiments reveal it to be a suitable precursor for the deposition of halide free Cu–Co mixed-metal oxide thin films at relatively low temperatures.