Study on structure and oxide ionic conductivity for new compound Ce(6-x)Ln(x)MoO(15-delta)

A new compound Ce(6-x)Ln(x)MoO(15-delta) has been synthesized by wet-chemistry method. Their crystal structure and oxide ionic conductivity were characterized by powder X-ray diffraction, Raman, IR spectrum and A.C. impedance technique. The XRD results showed that Ce6MO15-delta, Ce(5)LnMoO(15-delta) have cubic symmetry with Fm3m space group. The refined lattice parameters showed that their lattice constants decrease with the decrease of the ionic radius of Ln(3+). The electrochemical measurements showed that the ionic conductivity of resulting oxides Ce(6-x)Ln(x)MoO(15-delta) have an enhance, which may be a kind of promising material for SOFCs.

Crystallization and characterization of substoichiometric compound (W0.5Al0.5)C-0..5 obtained by solid-state reaction

(W0.5Al0.5)C-0.5 substoichiometric compound is synthesized by a combination of mechanical milling and high-pressure reactive sintering. X-ray diffraction is used to monitor the phase changes and crystallization of (W0.5Al0.5) C-0.5 during the whole reaction process. As a result, (W0.5Al0.5) C-0.5 is identified as the hexagonal WC-type belonging to the P-6m2 space group (No. 187), and the lattice parameters of (W0.5Al0.5)C-0.5 are calculated to be a = 2.907 (1) angstrom, c = 2.838 (1) angstrom, which are very similar to those of WC even if there are approximately 50 pct carbon vacancies in the cell of (W0.5Al0.5)C-0.5 as compared with WC. The substoichiometric (W0.5Al0.5)C-0.5 compound has a Vickers microhardness of 2385 +/- 70 kg mm(-2), which is as high as that of WC, while its density is far lower than that of WC.

Estimation thermal expansion coefficient from lattice energy for inorganic crystals

By using the study of the lattice energy and the structural parameters of binary inorganic crystals, a new parameter reflecting the thermal expansion property has been found, the relation between the linear expansion coefficient and new parameter has been established. A semiempirical method for evaluation of linear expansion coefficient from the lattice energy is presented, and developed to the complex crystals. The estimated values of the linear expansion coefficients of both simple and complex crystals are in good agreement with the experimental values.

Patterning and optical properties rhodamine B-doped organic-inorganic silica films fabricated by sol-gel soft lithography

Rhodamine B (RB)-doped organic-inorganic silica films and their patterning were fabricated by a sol-gel process combined with a soft lithography. The resulted film samples were characterized by atomic force microscope (AFM), optical microscope and UV/Vis absorption and photoluminescence excitation and emission spectra. The effects of the concentration of the RB dye and heat treatment temperature on the optical properties of the hybrid silica films have been studied. Four kinds of patterning structures with film line widths of 5, 10, 20 and 50 mum have been obtained by micromolding in capillaries by a soft lithography technique. The RB-doped hybrid silica films present a red color, with an excitation and emission bands around 564 and 585 mum, respectively. With increasing the RB concentration, the emission intensity of the RB-doped hybrid silica films increases and the emission maximum presents a red shift. The emission intensity of the films decreases with increasing the heat treatment temperatures.

A novel 2D arsenic vanadate network grafted with a transition metal complex: [Cu(phen)][(VV4As2O19)-V-IV-As-V]center dot 0.5H(2)O

A novel organic-inorganic hybrid compound [Cu(phen)](2)[(VV4As2O19)-V-IV-As-V-O-V].0.5H(2)O 1 has been hydrothermally synthesized. Its structure, determined by single crystal X-ray diffraction, exhibits an unusual two-dimensional arsenic vanadate layered network grafted with the [Cu(phen)](2+) complex. The chelating phen ligands project perpendicularly beyond the inorganic layer. Variable temperature magnetic susceptibility studies indicate that both ferro- and antiferro-magnetic interactions exist in 1.

New high-dimensional networks based on polyoxometalate and crown ether building blocks

Three novel supramolecular assemblies constructed from polyoxometalate and crown ether building blocks, [(DB18C6)Na(H2O)(1.5)](2)Mo6O19.CH3CN, 1, and [{Na(DB18C6)(H2O)(2)}(3)(H2O)(2)]XMo12O40.6DMF.CH3CN (X = P, 2, and As, 3; DB18C6 = dibenzo-18-crown-6; DMF = N,N-dimethylfomamide), have been synthesized and characterized by elemental analyses, IR, UV-vis, EPR, TG, and single crystal X-ray diffraction. Compound 1 crystallizes in the tetragonal space group P4/mbm with a = 16.9701(6) Angstrom, c = 14.2676(4) Angstrom, and Z = 2. Compound 2 crystallizes in the hexagonal space group P6(3)/m with a = 15,7435(17) Angstrom, c = 30.042(7) Angstrom, gamma = 120degrees, and Z = 2. Compound 3 crystallizes in the hexagonal space group P6(3)/m with a = 15.6882(5) Angstrom, c = 29.9778(18) Angstrom, gamma = 120degrees, and Z = 2. Compound 1 exhibits an unusual three-dimensional network with one-dimensional sandglasslike channels based on the extensive weak forces between the oxygen atoms on the [Mo6O19](2-) polyoxoanions and the CH2 groups of crown ether molecules, Compounds 2 and 3 are isostructural, and both contain a novel semiopen cagelike trimeric cation [{Na(DB18C6)(H2O)(2)}(3)(H2O)(2)](3+). In their packing arrangement, an interesting 2-D "honeycomblike" "host" network is formed, in which the [XMo12O40](3-) (X = As and P) polyoxoanion "guests" resided.

Modified polyoxometalates: Hydrothermal syntheses and crystal structures of three novel reduced and capped Keggin derivatives decorated by transition metal complexes

Three novel polyoxometalate derivatives decorated by transition metal complexes have been hydrothermally synthesized. Compound 1 consists of [(PMo6Mo2V8O44)-Mo-VI-V-V-O-IV{CO (2,2'-bipy)(2)(H2O)}(4)](3+) polyoxocations and [(PMo4Mo4V8O44)-Mo-IV-V-V-O-IV{Co(2,2'-bipy)(2)(H2O)}(2)](3-) polyoxoanions, which are both built on mixed-metal tetracapped [PMo8V8O44] subunits covalently bonded to four or two {Co(2,2'-bpy)(2)(H2O)}(2+), clusters via terminal oxo groups of the capping V atoms. Compound 2 is built on [(PMo8V6O42)-V-VI-O-IV{Cu-I(phen)}(2)](5-) clusters constructed from mixed-metal bicapped [(PMo8V6O42)-V-VI-O-IV](7-) subunits covalently bonded to two {Cu(phen)}(+) fragments in the similar way to 1. The structure of 3 is composed of [(PMo9Mo3O40)-Mo-VI-O-V](6-) units capped by two divalent Ni atoms via four bridging oxo groups.

Multifunctional organic-inorganic multilayer films of tris(2,2 '-bipyridine)ruthenium and decatungstate

A new multifunctional multilayer films consisting of tris(2,2'-bipyridyl)ruthenium(II) (Rubpy) and sodium decatungstate (W-10) have been prepared by the layer-by-layer (LbL) self-assembly method on ITO substrate. X-ray photoelectron spectra (XPS) confirmed the existence of W10 and Rubpy. Cyclic voltammetry (CV) and UV-Vis spectroscopy demonstrated the uniform assembly of (W-10/Rubpy) multilayer films. The multilayer films possess electrocatalytic activities on the reduction of iodate and oxidation of oxalate. Moreover, the films exhibited electrochemiluminescence (ECL) with tripropylamine (abbreviated as TPA) as the coreactant and the ECL response was proportional to the number of (W-10/Rubpy) layers. These characteristics of the multilayer films might find potential applications in the field of sensors and materials fields.

Novel polyoxometalate-templated, 3-D supramolecular networks based on lanthanide dimers: Synthesis, structure, and fluorescent properties of [Ln(2)(DNBA)(4)(DMF)(8)][Mo6O19] (DNBA=3,5-dinitrobenzoate)

The spherical Lindquist type polyoxometalate, Mo6O192-, has been used as a noncoordinating anionic template for the construction of novel three-dimensional lanthanide-aromatic monocarboxylate dimer supramolecular networks [Ln(2)(DNBA)(4)(DMF)(8)][Mo6O19] (Ln = La 1, Ce 2, and Eu 3, DNBA = 3,5-dinitrobenzoate, DMF = dimethylformamide). The title compounds are characterized by elemental analyses, IR, and single-crystal X-ray diffractions. X-ray diffraction experiments reveal that two Ln(III) ions are bridged by four 3,5-dinitrobenzoate anions as asymmetrically bridging ligands, leading to dimeric cores, [Ln(2)(DNBA)(4)(DMF)(8)](2+); [Ln(2)(DNBA)(4)(DMF)(8)](2+) groups are joined together by pi-pi stacking interactions between the aromatic groups to form a two-dimensional grid-like network; the 2-D supramolecular layers are further extended into 3-D supramolecular networks with 1-D box-like channels by hydrogen-bonding interactions, in which hexamolybdate polyanions reside. The compounds represent the first examples of 3-D carboxylate-bridged lanthanide dimer supramolecular "host" networks formed by pi-pi stacking and hydrogen-bonding interactions encapsulating noncoordinating "guest" polyoxoanion species. The fluorescent activity of compound 3 is reported.

Novel two-dimensional sodium molybdenum phosphates containing {M(enMe)(2)}(2+) bridging groups (M = Ni, Cu; enMe=1,2-diaminopropane)

Two novel organic-inorganic hybrid compounds, (H(2)enMe)(4)(H3O)[Ni(enMe)(2)].[Na3Mo12O52P8(OH)(10)].5H(2)O (1) and (H(2)enMe)(4)(H3O)[Cu(enMe)(2)].[Na3Mo12O52P8(OH)(10)].5H(2)O (2) (enMe = 1,2-diaminopropane), have been hydrothermally synthesized and characterized by elemental analyses, IR, EPR, XPS, UV-Vis spectra and TG analyses. Single crystal X-ray diffraction shows that 1 and 2 are isostructural compounds. Both the compounds exhibit an unusual two-dimensional (2-D) window-like network consisting of one-dimensional (1-D) chains of sodium molybdenum phosphate anions connected by transition metal coordination complexes cations. Compound 1 and 2 represent the first 2-D molybdenum phosphate skeleton pillared by transition metal complex fragments.

A two-dimensional molybdenum (V) phosphate with covalently bonded transition metal coordination complexes: hydrothermal synthesis and structure characterization of Na-2[{Mn(phen)(2)(H2O)}{Mn(phen)(2)}(3){Mn (Mo12O24)-O-V (HPO4)(6)(PO4)(2)(OH)(6)}] center dot 4H(2)O (phen=1,10-phenanthroline)

An organic-inorganic hybrid molybdenum phosphate, Na-2[{Mn(phen)(2)(H2O)} {Mn(phen)(2)}(3){(MnMo12O24)-O-v (HPO4)(6)(PO4)(2) (OH)(6)}] . 4H(2)O (phen=1,10-phenanthroline), involving molybdenum present in V oxidation state and covalently bonded transition metal coordination complexes, has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Deep brown-red crystals are formed in the triclinic system, space group P (1) over bar, a=16.581(l)Angstrom, b=18.354(1)Angstrom, c=24.485(2)Angstrom, alpha=80.589(l)degrees, beta=71.279(1)degrees, gamma=67.084(1)degrees, V=6493.8(8)Angstrom(3), Z=2, lambda(MoKalpha)=0.71073Angstrom (R(F)=0.0686 for 29,053 reflections). Data were collected on a Bruker Smart Apex CCD diffractometer at 293 K in the range of 1.76 < theta < 28.06degrees using omega-2theta scans technique. The structure of the title compound may be considered to be based on {Mo6O12(HPO4)(3)(PO4)(OH)(3)} units bonded together with {Mn(phen)(2)} subunits into a two-dimensional network. Two types of tunnels are observed in the solid of the title compound.

The synthesis and crystal structure of vanadium complexes: [(VO2)-O-IV(phen)(2)]center dot 6H(2)O and [2,2 '-(bipy)(2)(VO2)-O-V](H2BO3)center dot 3H(2)O

The organic-inorganic hybrid materials vanadium oxide [(VO2)-O-IV(phen)(2)](.)6H(2)O (1) and [(2,2'-bipy)(2)(VO2)-O-V](H2BO3)(.)3H(2)O (2) have been conventional and hydrothermal synthesized and characterized by single crystal X-ray diffraction, elemental analyses, respectively. Although the method and the ligand had been used in the syntheses of the compounds (1) and (2) are different, they almost possess similar structure. They all exhibit the distorted octahedral [VO2N4] unit with organonitrogen donors of the phen and 2,2'-bipy ligands, respectively, which coordinated directly to the vanadium oxide framework. And they are both non-mixed-valence complexes. But the compound (1) is isolated, and the compound (2) consists of a cation of [(2,2'-bipy)(2)(VO2)-O-V](+) and an anion of (H2BO3)(-). So the valence of vanadium of (1) and (2) are tetravalence and pentavalence, respectively. Meanwhile it is noteworthy that pi-pi stacking interaction between adjacent phen and 2,2'-bipy groups in compounds I and 2 also play a significant role in stabilization of the structure. Thus, the structure Of [(VO2)-O-IV(phen)(2)](.)6H(2)O and [(2,2'-bipy)(2)(VO2)-O-V](H2BO3)(.)3H(2)O are both further extended into interesting three-dimensional supramolecular.

A novel 3D network coordination polymer consisting of paddlewheel Co-3 clusters connected by PO4 and 4-pyridinecarboxylate

The synthesis, structural characterization and preliminary magnetic studies of a novel coordination polymer with paddlewheel Co-3 clusters are reported firstly. In the polymer, Co-3 clusters are covalently linked through PO4 tetrahedra and 4-pyridinecarboxylate (4-pya) ligands into interpenetrated three-dimensional network.