WO3-based electrochromic system with hybrid organic–inorganic gel electrolytes

Thin metal oxide films for a WO₃-based symmetric electrochromic system with a nickel oxide layer as the counter electrode have been prepared by spray pyrolysis on SnO₂:F coated soda-lime float glass, at a temperature of 670–720 °C and using metal acetylacetonates as precursors. The films have been characterized for composition and morphology by scanning electron microscopy equipped with an X-ray energy dispersive analyzer (SEM/EDAX), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Electrochromic properties have been examined in the electrochemical cells of a smart window arrangement using lithium ion doped sol–gel derived organic–inorganic hybrid materials as electrolytes. Hybrids with room-temperature ionic conductivities of 10^?4–10^?3 Ω^?1 cm^?1 have been synthesized from tetraethyl orthosilicate (TEOS) with an addition of 35 mass % of organic compounds. Coloration-bleaching of WO₃ films with lithium ions from hybrid electrolytes has resulted in the desired modulating the properties in the visible and near infrared spectrum range. An XPS analysis has shown the presence of a lower oxidized tungsten oxide phase (WO_2.92) in the WO₃ film.     

Molecular dynamics simulations of the crystal–melt interface mobility in HCP Mg and BCC Fe

The temperature profile around the moving solid–liquid interface during non-equilibrium molecular dynamics (MD) simulations of crystallization and melting is examined for HCP Mg and BCC Fe. An evident spike (valley) is found around the solid–liquid interface during solidification (melting). Considering the effect of a non-uniform temperature distribution, it is found that, if the actual interface temperature is adopted to compute the interface mobility, rather than the thermostat temperature (or the mean temperature of the whole system), the kinetic coefficient is approximately a factor of two larger than previous estimates. Although the magnitude of the kinetic coefficient is larger than the previous estimates, the crystalline anisotropies derived in the current work are consistent with earlier calculations.     

Organic/inorganic hybrid compound: α-Dodecamolybdophosphoric acid–3-(4,5-diazafluoren-one)-3–water

In the title compound (C₁₁H₆N₂O)₃·H₃PMo₁₂O₄₀·3H₂O(1), the -dodecamolybdophosphoric acid residue has the Keggin structure, with M–O distance ranging between 1.673(5) and 2.464(4) Å. The water molecules are involved in O–H···N and O–H···O intermolecular hydrogen bonds with the diazafluoren moiety and -dodecamolybdophosphoric acid respectively while the diazafluoren moiety and -dodecamolybdophosphoric acid are connected through C–H···O interactions. The O–H···O intermolecular hydrogen bonds form infinite chains of Mo₁₂O₄₀ units in which N···O contacts interconnect the chains to form layers.     

Preparation of hybrid CaCO3–pepsin hemisphere with ordered hierarchical structure and the application for removal of heavy metal ions

In this paper, a simple way for preparation of hybrid CaCO₃–pepsin material with ordered hierarchical structure was reported. It could be observed that the nanoparticles self-assembled into a lot of tetrahedral calcite crystals, which assembled into highly ordered surfaces of hemisphere-shaped CaCO₃ with hierarchical structures. These products were characterized by X-ray powder diffraction (XRD), Scanning electron microscope (SEM), High resolution transmission electron microscopy (HRTEM), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetry-differential thermal analyses (TG-DTA) and photoluminescence (PL). A rational mechanism was proposed for the formation of hybrid CaCO₃–pepsin material ordered hierarchical structure. Functional study using the hybrid CaCO₃–pepsin material as an adsorbent for removal of heavy metal ions demonstrates that its distinguishing features in water treatment involve not only high removal capacities, but also decontamination of trace ions. The acquired experimental data show that both the functional and hierarchical structural features of hybrid CaCO₃–pepsin material provide a promising adsorbent for removal of heavy metal ions.     

Incorporation of group III,IV and V elements in 3C–SiC(1 1 1) layers grown by the vapour–liquid–solid mechanism

We report on a comparative investigation of the incorporation of group III, IV and V impurities in 3C–SiC heteroepitaxial layers grown by the vapour–liquid–solid (VLS) mechanism on on-axis α-SiC substrates. To this end, various Si-based melts have been used with addition of Al, Ga, Ge and Sn species. Homoepitaxial α-SiC layers grown using Al-based melts were used for comparison purposed for Al incorporation. Nitrogen incorporation depth profile systematically displays an overshoot at the substrate/epilayer interface for all the layers. Ga and Al incorporations follow the same distribution shape as N whereas this is not the case for the isoelectronic impurities Ge and Sn. This suggests some interaction between Ga/Al and N coming from the high bonding energy between the group III and V elements, which does not exist with Ge and Sn. This is why both incorporate as a cluster. A model of incorporation is proposed taking into account metal-N and metal-C bonding energies together with the solid solubility of the corresponding nitrides.     

Concentration dependence of Dy3+:1.3 μm luminescence in Ge–Ga–Sb–Se glasses

The Ge₂₅Ga₅Sb₅Se₆₅ glasses, doped with 0.01, 0.05, 0.1, 0.2, and 0.5 mol% of Dy³⁺ ions are prepared and the concentration dependence of Dy³⁺:1.3 μm luminescence is investigated. Remarkable energy migration between Dy³⁺ ions occurs as its concentration is more than 0.05 mol%. With further increasing amount of Dy³⁺ ions, the decay time of the 1.3 μm fluorescence decreases rapidly. All the decays are simple exponential and possible regimes of the donor decay are discussed.     

Some Aspects of Interactions in the Mo–W–Al2O3–H2 System: Formation of Polyoxides

The possibility of formation of molybdenum and tungsten polyoxides in the Mo–W–Al₂O₃–H₂ system at T = 2400 K and P = 1 bar in a controlled Ar + H₂ atmosphere has been investigated by the method of thermodynamic analysis. The formation of polyoxides is found to occur both due to the processes involving Al₂O₃ melt and in the absence of the latter. It is established that metals (Mo and W) and their mono-, di-, and even trioxides (in the latter case, mediated polymerization occurs) can be used as initial components to form polyoxides. It is shown that polyoxides themselves may interact with one of their main sources: Al₂O₃ melt.

     

Sol–gel synthesis and photoluminescence of RE3BO6: Eu3+/Tb3+ (RE = Y, Gd) microcrystalline phosphors from hybrid precursors

Novel phosphors of Eu³⁺/Tb³⁺ doped RE₃BO₆ (RE = Y, Gd) have been prepared using an original modified in situ sol–gel synthesis route. Different optimized organic media were mixed with rare earth coordination polymers, and tri-n-butyl borate was added to assemble inorganic/organic multi-component hybrid precursors. After calcinations of the resulting precursors at 1000 °C, target phosphors were obtained. The microstructure and morphology information of the phosphors were investigated via the technique of X-ray powder diffraction (XRD) and scanning electronic microscopy, and it has been shown that these phosphors present symmetrical distribution and high packing density, whose grain sizes were around 200 nm. Analyzed by luminescent spectra, these phosphor particles show narrow lines of emissions respectively originating from their characteristic transitions, and the dominating emission peak is due to the hypersensitive transition. The RE₃BO₆: Eu³⁺/Tb³⁺ (RE = Y, Gd) phosphors can be expected to gain more practical applications in commercial phosphors and other luminescent materials used in advanced devices.     

Growth of Crystals of Solid Solutions with Tysonite Structure in the PbF2–RF3 Systems (R = Pr,Nd)

Crystallography Reports - Crystals of the R1 – yPbyF3 – y (R = Pr (0 ≤ y ≤ 0.09) or Nd (0 ≤ y ≤ 0.10)) solid solutions with a...     

Production of Complex Hydrosulphates in the K3H(SO4)2–Rb3H(SO4)2 Series: II. Phase Equilibria in the K2SO4–Rb2SO4–H2SO4–H2O System

Crystallography Reports - The phase equilibria in the K2SO4–Rb2SO4–H2SO4–H2O system have been investigated under isothermal conditions at 25°C. The concentration limits of...     

Production of Complex Hydrosulphates in the K3H(SO4)2–Rb3H(SO4)2 Series: Part I

Crystallography Reports - The phase equilibria in the K3H(SO4)2–Rb3H(SO4)2–H2O cross section have been investigated under isothermal conditions at 25°C. The concentration limits of...     

Ca–Mg mixing in aluminosilicate glasses: An investigation using 17O MAS and 3QMAS and 27Al MAS NMR

To better understand non-framework cation mixing in Ca–Mg aluminosilicate glasses, ¹⁷O MAS and 3QMAS NMR studies were done on glasses on the Mg₃Al₂Si₃O₁₂–Ca₃Al₂Si₃O₁₂ join as well as several compositions with lower Al/Si ratios. While not all of the oxygen sites are fully resolved, the non-bridging oxygen associated with two Ca and one Mg cations is under-represented relative to that predicted by a model assuming random Ca/Mg mixing. Therefore, local non-bridging oxygen environments are rich in Mg, and extra Ca must be associated with charged bridging oxygens such as Al–O–Si. The deviation from random mixing increases as the Al/Si ratio decreases and as X_Mg approaches 0.50, suggesting a reduction in configurational entropy that may be compensated for by other sources, including mixing of network forming cations. Al–O–Al is detected, and appears to increase with increasing X_Mg and increasing Al/Si. High field ²⁷Al MAS NMR also shows that these glasses all have substantial concentrations of ^[5]Al, but no detectable ^[6]Al (0.5% detection limit). The amount of ^[5]Al increases non-linearly as X_Mg increases and very slightly as Al/Si increases.     

New Data on the Isomorphism in Eudialyte-Group Minerals. VI: Crystal Structure of the First Member Containing Sulfide Anion with Isomorphic Substitution Cl––S2–

Crystallography Reports - An eudialyte-group representative containing S2– sulfide anion has been investigated by X-ray diffraction analysis, electron-probe microanalysis, and IR...     

The Crystal-Chemical Features of Phases and the Nature of the Coordination Bond in the System [CuxNi(1 – x){N(CH2PO3)3}]Na4 · nH2O (x = 0–1)

Crystallography Reports - The structural features of the phases formed during crystallization of mixed copper and nickel complexes with nitrilotris(methylenephosphonic acid)...     

Synthesis and structure–property relations in xCuO–(1 − x)Bi2O3 (0.5 ⩽ x ⩽ 0.9) (C1–C5: x = 0.5, 0.6, 0.7, 0.8, 0.9) glasses

Synthesis of the xCuO–(1 ? x)Bi₂O₃ (0.5 ? x ? 0.9) (C1–C5: x = 0.5, 0.6, 0.7, 0.8, 0.9) glasses was done via nitrate–citrate gel route. Glassy phase is ascertained by XRD studies. Magnetic susceptibility results in the range 4.2–400 K show weak paramagnetic nature with exchange integrals ～0.024–0.13 eV in the glasses. The electron paramagnetic resonance (EPR) in the range 4.2–363 K shows g ≈ 2.0 and the trend of the g-matrix elements g_|| > g_⊥ > g_e for the glasses C1–C5 at 4.2 K are due to the Cu²⁺ (3d⁹) paramagnetic site in the glasses which is in a tetragonally elongated octahedron [O_1/2–CuO_4/2–O_1/2] having D_4h symmetry. IR spectroscopic results show the presence of octahedron [BiO_6/2]^3? and [CuO_6/2]^4? units and pyramidal [BiO_2/2O]^? unit in the glasses.     

Reaction of bis(dimethoxyphosphino)dimethylhydrazine (dmpdmh) with Ru3(CO)12: Evidence for facile ligand fragmentation in Ru3(CO)10(dmpdmh) to give Ru4(CO)12[μ-N(Me)N(Me)], Ru3(CO)11[P(OMe)3], and Ru3(CO)9[μ-P(OMe)3]

Thermolysis of the cluster Ru₃(CO)₁₂ with the bis(phosphanyl)hydrazine ligand (MeO)₂PN (Me)N(Me)P(OMe)₂ (dmpdmh) in toluene at 75°C furnishes the known clusters Ru₄(CO)₁₂ [-N(Me)N(Me)] (2) and Ru₃(CO)₁₁[P(OMe)₃] (3), in addition to the new cluster Ru₃ (CO)₁₀(dmpdmh) (1) and the phosphite-tethered cluster Ru₃(CO)₉[-P(OMe)₃] (4). The simple substitution product Ru₃(CO)₁₀(dmpdmh), a logical intermediate to clusters 2–4, was synthesized by treating Ru₃(CO)₁₂ with Me₃NO in CH₂Cl₂ at room temperature, and independent thermolysis reactions using cluster 1 was shown to yield clusters 2–4. The solid-state structure of clusters 2 and 4 were unequivocally established by X-ray diffraction analysis. Ru₄(CO)₁₂[-N(Me)N(Me)] crystallizes in the orthorhombic space group Pnna (#52), a = 12.913(1), b = 13.3238(6), c = 12.5690(8) Å, V = 2162.5(2) ų, Z = 4, and d _calc = 2.452 g/cm³. Ru₃(CO)₉[-P(OMe)₃] crystallizes in the triclinic space group P a = 9.586(1), b = 14.354(1), c = 14.997(2) Å, = 89.82(1)°, = 98.36(1)°, = 92.010(8)°, V = 2040.4(4) ų, Z = 4, and d _calc = 2.212 g/cm³. The coordination of the dimethylazo linkage to the four ruthenium atoms in 2 and the phosphorus atom and one of the oxygen atoms of the methoxy groups to the three ruthenium centers in 4 are confirmed by X-ray analysis.     

Dinuclear Ir(III) Complex with an Unusual η<Superscript>1</Superscript>:η<Superscript>3</Superscript>-allylic Bridging Ligand from the Double C–H Activation of 2,5-Dimethylthiophene

Abstract  

The unique dinuclear Ir(III) complex (Cp*IrCl)(μ-H)[μ-(η¹:η³-C₆H₆S)](IrCp*) (1) has been synthesized and characterized by NMR spectroscopy (¹H and ¹³C), elemental analysis, and single crystal X-ray diffraction. It is the first structurally determined complex in which an activated thiophene ligand displays an η³-allylic interaction. 1 appears to form from successive C-H bond activations of 2,5-dimethylthiophene, resulting in its bridging the two iridium centers. The η³-allylic interaction occurs with one of the Ir centers and has Ir–C_thio bond lengths ranging from 2.133(5)-2.207(5) ?; the C–C double bond involved in the interaction has a bond length of 1.438(7) ? compared to 1.348(8) ? for the uncoordinated C–C double bond. The 3-carbon of the thiophene ring bridges both iridium centers with bond lengths of 2.036(5) ? and 2.208(5) ?. 1 crystallizes in space group P−1 with cell constants a = 8.6303(6) ?, b = 9.0153(6) ?, c = 18.1089(12) ?, α = 84.728(1)°, β = 87.534(1)°, γ = 64.373(1)°, and Z = 2. The structure was solved by direct methods and refined to R = 0.0363 (F ² > 2σ(F ²)) and wR = 0.0851 (F ²). The NMR data indicate the solution state structure is consistent with the solid state structure.