Hydrothermal synthesis of Fe and Mn doped SnO2 and its magnetic structures

The dilute magnetic semiconductor of Sn1-x-yMnxFeyO2 (0 <= x <= 0.10, 0 <= y <= 0.10) Were syhthesized with the hydrothermal method using SnCl4, Mn(CH3COO)(2) center dot 4H(2)O and FeCl3 center dot 6H(2)O as the raw materials. The structure, morphologies and magnetic properties of the sample were characterized via X-ray powder diffractometer(XRD), transmission electron microscopy(TEM), Raman spectrum and superconducting and quantum interference device(SQUIT), and Mossbeaur spectrum. No secondary phase was found in the XRD spectrum. The morphology of the samples is affected by the kind or the mount of transition metal. The local vibrating model-of Mn Positioned SnO2 sites was found in Raman spectrum. The measured magnetic results indicate that when x = 0.10, y = 0, the sample exhibits strong magnetization in low-temperature (5 K), but the magnetization decrease rapidly at room. temperature; In contrast, when x = 0, y = 0.1, the sample's magnetization and coercivity are both small, but being temperature independent. Mossbeaur spectra indicates that part of the Fe is ferromagnetic coupled, and the simulating results indicate that the ferromagnetic character is intrinsic.

Hydrothermal synthesis, structure characterization of a new mixed Mo/V metal-oxygen cluster compound: [Co(phen)(3)](2)[HPMo4V (Mo4V6IV)-V-VI M2O44]center dot 4H(2)O, (M=0.78Mo(V)+0.22V(IV))

A new polyoxometalate [Co(phen)(3)](2)[HPMo4V Mo-4(VI) V-6(IV) M2O44]center dot 4H(2)O (M = 0.78Mo(V)+ 0.22V(IV)) 1 was hydrothermally synthesized and characterized by IR, elemental analyses, X-ray photoelectron spectrum, ESR and single crystal X-ray diffraction. The title compound is in the triclinic space group P (1) over bar with a = 12.0953(7) angstrom, b = 14.0182(6) angstrom, c = 14.6468(7) angstrom, V=2402.55(18) angstrom(3), alpha = 105.134(2), beta = 91.841(3), gamma = 91.401(2), Z = 1, and R-1 (wR(2)) = 0.0617 (0.1701). The compound was prepared from tetra-capped pseudo-Kepin with phosphorus-centered polyoxoanions [PMo8V6M2O44](5-) , [Co(phen)(3)](2+) cations and linked through hydrogen bonds and pi-pi stacking interaction into three-dimensional supramolecular framework. Astudy of the magnetic properties of 1 demonstrates that it exhibits antiferromagnetic coupling interactions.

Hydrothermal synthesis of ZrW2O8 nanorods

Negative thermal expansion ZrW2O8 nanorods were synthesized by a rapid low-temperature hydrothermal route, followed with a heat treatment at 500 degrees C for 6h. Acidity of the HCl addition to the mixed solution in the hydrothermal condition strongly affects the formation of the precursor ZrW2O7(OH)(2)(H2O)(2). High acidity of HCl in the range of 5-10 N facilitates the nucleation of ZrW2O7(OH)(2)(H2O)(2), but constrains its growth. Low acidity of HCl addition (< 5 N) only obtained the products ZrO2 and WO3 by firing the precursors. FE-SEM images revealed that the shape and size of ZrW2O8 were modeled after its precursor ZrW2O7(OH)(2)(H2O)(2).

The first discrete mixed-valence hexadecavanadate host shell cluster anions: hydrothermal synthesis, structure and characterization of [V16O38(Cl)](8-)

A new compound, [NH4](2)[Zn(phen)(3)](2)[Zn(phen)(2)(H2O)(2)][V16O38(Cl)] (.) 5H(2)O (1), was synthesized in the hydrothermal condition. The "naked" [V16O38(Cl)](8-) is the first observation with host shell structure in polyoxovanadate chemistry.

Hydrothermal synthesis and crystal structure of a sulfur-bridged binuclear copper(II) coordination polymer generated by a spontaneous reduction

A simultaneous reduction SO42- to S2- by 2,5-pyridinedicarboxylate under hydrothermal conditions produced a new binuclear copper(II) coordination polymer [CuS(4,4'-bipy)](n) (4,4-bipy = 4,4'-bipyridine) (1). Single crystal X-ray analysis revealed that compound I consisted of sulfur-bridged binuclear copper(II) units with Cu-Cu bonding which were combined with 4,4-bipy to generate a three-dimensional network constructed from mutual interpenetration of two-dimensional (6,3) nets. Crystal data for 1:C10H8CuN2S, tetragonal 14(1)/acd, a = 14.0686(5) Angstrom, b = 14.0686(5) Angstrom, c = 38.759(2) Angstrom, Z = 32. Other characterizations by elemental analysis, IR, EPR and TGA analysis were also described in this paper.

Vaterite-type YBO3 : Eu3+ crystals: hydrothermal synthesis, morphology and photoluminescence properties

Vaterite-type YBO3:Eu3+ crystals with interesting flower and hedgehog fungus-like structures composed of nanosheets were obtained by controlled crystallization of Y2O3 and Eu2O3 in H3BO3 solutions under acidic hydrothermal (HT) conditions. Nanosheets of uniform thicknesses were formed by preferential crystal growth along the (100) crystallographic plane and specific three-dimensional structures were further developed through a homocentric growth mechanism. Optical emission measurements showed that the HT-grown nanosheet crystals exhibited a higher ratio of the emitted red-to-orange light ratio than crystals grown from solid-state reactions. The photoluminescence intensity and emission lifetimes were also studied as a function of the Eu3+ dopant concentration and the HT synthesis temperature. The effect of some additives: a chelating ligand, a surfactant and a polymer, on the YBO3:Eu3+ crystals morphology was also investigated.

Engineering white light-emitting Eu-doped ZnO urchins by biopolymer-assisted hydrothermal method

With the presence of biopolymer-sodium alginate as additive, Eu-doped ZnO (zinc oxide) urchins consisting of nanorods were synthesized through a hydrothermal route. X-ray diffraction pattern makes evident the absence of phase other than wurtzite ZnO. Upon excited by 325 nm xenon laser, such nanostructured Eu-doped ZnO urchins emit white light, which originates from the luminescence of ZnO and the intra-4f transitions of Eu3+ ions. Besides acting as stabilizing agent, sodium alginate may also sensitize the Eu3+ ions in the nanostructures and facilitate the energy transfer from the host to Eu3+ ions. (c) 2006 American Institute of Physics.

In(OH)(3) and In2O3 nanorod bundles and spheres: Microemulsion-mediated hydrothermal synthesis and luminescence properties

Indium hydroxide, In(OH)(3), nano-microstructures with two kinds of morphology, nanorod bundles (around 500 nm in length and 200 nm in diameter) and caddice spherelike agglomerates (around 750 - 1000 nm in diameter), were successfully prepared by the cetyltrimethylammonium bromide (CTAB)/water/cyclohexane/n-pentanol microemulsion-mediated hydrothermal process. Calcination of the In(OH)(3) crystals with different morphologies (nanorod bundles and spheres) at 600 degrees C in air yielded In2O3 crystals with the same morphology. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and photoluminescence (PL) spectra as well as kinetic decays were used to characterize the samples. The pH values of microemulsion play an important role in the morphological control of the as-formed In(OH)(3) nano-microstructures from the hydrothermal process. The formation mechanisms for the In( OH) 3 nano- microstructures have been proposed on an aggregation mechanism. In2O3 nanorod bundles and spheres show a similar blue emission peaking around 416 and 439 nm under the 383-nm UV excitation, which is mainly attributed to the oxygen vacancies in the In2O3 nano-microstructures.

Hydrothermal growth and gas sensing property of flower-shaped SnS2 nanostructures

Unusual 3D flower-shaped SnS2 nanostructures have been synthesized using a mild hydrothermal treatment in the presence of octyl-phenol-ethoxylate ( Triton X-100) at 160 degrees C. The nanostructures have an average size of 1 mu m, and consist of interconnected nanosheets with thicknesses of about 40 nm. Based on time-dependent experimental results, we ascribe the oriented attachment mechanism to the growth of the SnS2 nanostructures. The nonionic surfactant Triton X-100 plays a key role in the formation of the flower-like morphology. Room temperature gas-sensing measurements show that the 3D SnS2 nanostructures could serve as sensor materials for the detection of NH3 molecules.

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.

Hydrothermal synthesis, structure, and characterization of two one-dimensional chainlike hybrid complexes [(CuX)(2)(o-phen)](infinity) (X = Br, Cl; o-phen = o-phenanthroline)

Two novel organic-inorganic hybrid complexes [(CuX)(2)(o-phen)](infinity) (X = Br (1), Cl (2); o-phen = o-phenanthroline) have been synthesized hydrothermally and characterized structurally by elemental analyses, IR, ESR, XPS spectrum, TG analyses and single-crystal X-ray diffraction. Both title compounds exhibit novel one-dimensional chainlike copper halide scaffolding constructed by the unusual [Cu3X3] hexagon motifs by sharing opposite edges, where a single Cu site of each [Cu3X3] hexagon is chelated with N donors of o-phen group. To our knowledge, such basic o-phen-copper halide skeleton has not been reported hitherto. Moreover, TG analyses indicate that both title compounds possess high thermal stability.

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.

Hydrothermal syntheses and crystal structures of bimetallic cluster complexes [{Cd(phen)(2)}(2)V4O12]center dot 5H(2)O and [Ni(phen)(3)](2)[V4O12]center dot 17.5H(2)O

The hydrothermal reactions of vanadium oxide starting materials with divalent transition metal cations in the presence of nitrogen donor chelating ligands yield the bimetallic cluster complexes with the formulae [{Cd(phen(2))(2)V4O12].5H(2)O (1) and [Ni(phen)(3)](2)[V4O12] . 17.5H(2)O (2). Crystal data: C48H52Cd2N8O22V4 (1), triclinic. P (1) over bar, a = 10.3366(10), b = 11.320(3), c = 13.268(3) Angstrom, alpha = 103.888(17)degrees, beta = 92.256(15)degrees, gamma = 107.444(14)degrees, Z = 1; C72H131N12Ni2O29.5V4 (2), triclinic. P (1) over bar, a = 12.305(3), b = 13.172(6), c = 15.133(4), alpha = 79.05(3)degrees, beta = 76.09(2)degrees, gamma = 74.66(3)degrees, Z = 1. Data were collected on a Siemens P4 four-circle diffractometer at 293 K in the range 1.59degrees < theta < 26.02degrees and 2.01degrees < 0 < 25.01degrees using the omega-scan technique, respectively. The structure of 1 consists of a [V4O12](4-) cluster covalently attached to two {Cd(phen)(2)}(2+) fragments, in which the [V4O12](4-) cluster adopts a chair-like configuration. In the structure of 2, the [V4O12](4-) cluster is isolated. And the complex formed a layer structure via hydrogen bonds between the V4O12](4-) unit and crystallization water molecules.

Hydrothermal and solvothermal synthesis of the complex fluoride alpha '-SrAlF5

The complex fluoride alpha'-SrAlF5 has been synthesized through hydrothermal and solvothermal methods under mild conditions. The effects of the molar ratio of starting materials, temperature, reaction time and solvents on the synthesis of alpha'-SrAlF5 were discussed. The final products were characterized by XRD and SEM. The rod-like shape of alpha'-SrAlF5 is shown in SEM images.