Single Crystal Growth and Physical Property Characterization of Non-centrosymmetric Superconductor PbTaSe_2

We report on the single crystal growth and superconducting properties of PbTaSe2 with the non-centrosymmetric crystal structure. By using the chemicM vapor transport technique, centimeter-size single crystals are success- fully obtained. The measurement of temperature dependence of electricaJ resistivity p（T） in both normal and superconducting states indicates a quasi-two-dimensional electronic state in contrast to that of polycrystalline samples. Specific heat C（T） measurement reveals a bulk superconductivity with Tc ≈ 3.75K and a specific heat jump ratio of 1.42. All these results are in agreement with a moderately electron-phonon coupled, type-g Bardeen-Cooper-Schrieffer superconductor.

Ionothermal Synthesis, Crystal Structure and Photocatalytic Property of a New Cobalt Coordination Polymer

The reaction of flexible bis（imidazole） ligand and 1,2-bis（imidazol-l＇-yl）methane （bimm） with Co（Ⅱ） salt under ionothermal method resulted in the formation of a new coordination polymer {[Co（bimm）3]·（PF6）2}n （1）. X-ray single-crystal diffraction determination reveals that 1 crystallizes in the triclinic Pi space group, with α = 8.647（6）, b = 12.092（9）, c = 14.967（1 l） A, α = 88.912（8）, β = 81.199（8）, ）, = 89.395（8）°, V= 1546 （2） A3, Z = 2, Mr = 793.39, Dc= 1.704 Mg/m3,μ = 0.768 mm-1 F（000） = 798, the final R = 0.0626 and wR = 0.1634 for 4319 observed reflections with I〉 2σ（I）. In compound 1, the Co（lI） ion is connected to another Co（ll） by two bimm ligands to form 1D double chains which are further linked by bimm ligands to form a 2D wavelike layer. Topologically, the structure of 1 represents a uninodal 2D 4-connected sq1/Shubnikov tetragonal plane net. Moreover, thermogravimetric analyses and photocatalytic property for 1 have also been investigated.

Synthesis,Crystal Structure and Magnetic Property of Ternary Neodymium Zirconium Sulfide,Nd2ZrS5

A new ternary neodymium zirconium sulfide Nd_2ZrS_5 was synthesized by high-temperature solid-state reaction and structurally characterized by single-crystal X-ray diffraction. It crystallizes in the orthorhombic space group Pnma（No. 62） belonging to the Y_2HfS_5 structure-type with a = 11.461（4）, b = 8.009（3）, c = 7.315（3） A, Z = 2 and V = 671.5（4）A3. Its structure features NdS_8 and ZrS_7 polyhedra-constructed a 3-D network. The data of magnetic susceptibility indicate its antiferromagnetic-like behavior without magnetic order down to 2 K.

Synthesis, Crystal Structure and Fluorescent Property of a Zn(Ⅱ) Complex with 1,3-Bis(imidazol-1-yl)benzene and 1,3-Benzenedicarboxylate

A novel zinc complex [Zn（BIB）（bdc）]n（1, BIB = 1,3-bis（imidazol-1-yl）benzene, bdc = 1,3-benzenedicarboxylate） has been synthesized in solvothermal conditions. The title complex was characterized by elemental analysis, IR spectra, thermal analysis, single-crystal and powder X-ray diffraction. The result proved that the alliance of BIB and aromatic carboxylic acids is good for the diversity of getatable structure. Complex 1 crystallizes in the monoclinic system of P2/c space group with a = 11.5591（10）, b = 9.6239（8）, c = 33.727（3）A, β = 103.816（3）°, V = 3643.4（5） A^3, Z = 8, μ = 1.385 mm^-1, F（000） = 1792, Dc = 1.603 g/cm^3 and Mr = 439.72 g/mol. Additionally, luminescent properties of complex 1 are also investigated and it shows good fluorescence.

Synthesis,Crystal Structure and Redox Property of a Copper(Ⅱ)Complex Based on 1,1-Bis(1H-benzoimidazol-2-ylmethyl)cyclohexane

A novel mononuclear copper（Ⅱ） complex [Cu（bbmc）Cl_2]·DMF,where bbmc is 1,1-bis（1H-benzoimidazol-2-ylmethyl）cyclohexane,was synthesized and characterized by X-ray single-crystal structure analysis.The complex crystallizes in triclinic,space group P1 with a = 9.1088（5）,b = 11.0075（4）,c = 14.2326（6）A,α = 97.188（3）,β = 96.394（4）,γ = 111.430（4）°,V = 1298.73（10） A^3,Z = 2,D_c = 1.409 g/cm^3,μ（Mo Kα） = 1.074 mm^-1,F（000） = 572,S = 1.078,R = 0.0381 and w R = 0.0876 for 5593 observed reflections with I 〉 2σ（I）.The central Cu（Ⅱ） ion adopts a distorted tetrahedral geometry coordinated by two nitrogen atoms of the ligand and two chloride ions.The complex showed its thermal decomposition temperature up to 226 ℃ and exhibited an irreversible one-electron transfer process involving Cu^Ⅱ/Cu^I couple.

Solvothermal Synthesis,Crystal Structure and Photoluminescence Property of a 3D Lead(Ⅱ)Coordination Polymer Based on Terephthalic Acid

Solvothermal reaction of Pb（NO3）2·6H2O with rigid linear ligand terephthalic acid（H2pta） in N,N-dimethylformamide（DMF） produced a new three-dimensional（3D） lead（Ⅱ）coordination polymer[Pb2（pta）1.5（μ4-OH）（DMF）]n 1,and its structure was characterized by single-crystal X-ray diffraction analyses.In polymer 1,the μ4-OH bridges the nearby lead（Ⅱ） ions into an infinite one-dimensional（1D） chain,and then the organic ligand pta^2- joins the neighbored chains into a 3D structure by two similar connection modes in different configurations.The solid-state photoluminescent studies revealed that 1 exhibits a strong greenish emission mainly originating from ligand-to-metal charge transfer between the delocalized π bonds of the aromatic carboxylate ligand pta^2- and the p orbitals of the Pb^2＋ centers.

Synthesis,Crystal Structure and Photoluminescent Property of a Novel Dy^(3+) Coordination Compound Containing Rare(H_2O)_(22) Clusters

A novel Dy^（3＋） coordination compound,（H_2pipz）（H_3O）[Dy（pydc）_3]·11H_2O（1,pipz = piperazine and H_2pydc = pyridine-2,6-dicarboxylic acid）,has been hydrothermally synthesized and characterized by X-ray single-crystal diffraction,elemental analysis. It is interesting that the packing structure of compound 1 contains 22-core water clusters. Compound 1 is extended into a threedimensional supramolecular structure via O···H···O hydrogen bonding interactions. Furthermore,the luminescent property of compound 1 was also investigated.

Synthesis,Crystal structure and Luminescent Property of a New 3D Supramolecular Compound(C_6 H_6NO_2)_3(C_6H_5NO_2)(PW_(12)O_(40))·2H_2O

A supramolecular compound （C6H6NO2）3（C6H5NO2）（PW12O40）·2H2O including the Keggin-type [PW1O40]3- polyanion, [HC6H5NO2]＋ （protonated pyridine-4-carboxylic acid molecule）, C6H5NO2 （pyridine-4-carboxylic acid molecule） and two free H20 molecules has been synthesized by the hydrothermal method and characterized by elemental analysis, IR spectra, single-crystal X-ray diffraction and powder X-ray diffraction. The crystal belongs to orthorhombic, space group Pnnm with a = 1.0483（3）, b = 1.4368（6）, c = 2.0526（7） nm, V= 3.0918（18） nm3,Z = 2, F（000） = 3004, Mr= 3406.07, Dc= 1.757 g.m-3,μ = 41.241 mm-1, the final R = 0.0387 and wR = 0.1089 for 2091 observed reflections withI〉 2σ（I）. A total of 30431 reflections were collected, of which 3083 were independent （Rint = 0.0605）. S is 1.182. The title compound presents a 3-D structure via intermolecular hydrogen bonds among [PW12O40]3- polyanions and pyridine-4-carboxylic acid ligands. The ultraviolet and luminescence spectra have been studied at room temperature, of which the purple fluorescent emission is located at 363 nm when excited at 264 nm. Fluorescent emission of the compound derives from the π-π＊ transitions in the pyridine-4-carboxylic acid ligands.

SYNTHESIS, MAGNETIC PROPERTY AND X-RAY CRYSTAL STUCTURE OF MIXED VALENT COBALT COMPLEX SALT [Co~Ⅲ Cl_2(py)_4][Co~Ⅱ Cl_3(py)]

Complex salt Co_2Cl_5(py)_5 (py=pyridine) was obtained by the reaction of CoCl_2·6H_2O with Bu_4NMnO_4 in pyridine in the presence of benzoic acid. It is monoclinic and crystallizes in space group P2_1/n, fw=690.64, a=28.652(5), b=14.108(4), c=7.424(3) ;β=90.09(1); V=3001(2)~3; Z=4, Dc=1.53g/cm^3. Final R factor is 0.041. The structure consists of a discrete cation [Co~ⅢCl_2(py)_4]^+ and an anion [Co~Ⅱ Cl_3(py)]^-. The Co~Ⅲ ion is coordinated by two Cl^- and four pyridine nitrogen atoms to form an octahedral geometry, and Co~Ⅱ is coordinated by three Cl^- and one pyridine nitrogen atom to form the apices of a tetrahedron. The variable-temperature magnetic susceptility measurement shows no magnet-exchange interaction between Co~Ⅲ and Co~Ⅱ ions.

Synthesis, Structure and Luminescent Property of a 2D Cd(Ⅱ) Coordination Polymer Based on Mixed-ligands of 1,3-Bis(imidazol)propane and Pyridine-3,5-dicarboxylic Acid

A new Cd（Ⅱ） coordination polymer, namely, [Cd（1,3-bip）（3,5-pdc）]n （1,3-bip = 1,3-bis（imidazol）propane and 3,5-pdc = pyridine-3,5-dicarboxylic acid） has been synthesized under hydrothermal conditions. Compound 1 was characterized by infrared spectrum, elemental analysis, powder X-ray diffraction （PXRD） and single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/c with a = 1.40178（7）, b = 1.72502（12）, c = 1.41635（6） ran, β = 92.653（4）°, V = 3.4212（3） nm3, Z = 4, C16HIsCdNsO4, Mr = 453.73, Dc = 1.762 g/cm3, F（000） = 1808,μ = 1.310 mm1, R = 0.0899 and wR = 0.1945. In compound 1, each 3,5-pdc ligand links three Cd（lI） ions and each Cd（Ⅱ） attaches to bip ligands to form a complicated 2D double-layer structure. In addition, the thermal stability and luminescent property of 1 have been studied in the solid state at room temperature.

Solidification and crystallization properties of CaO-SiO_2-Na_2O based mold fluxes

Crystallization properties play an important role in keeping a smooth running of continuous casting process and high surface quality of cast strands. To reduce fluorine pollution in slag, a new type of CaO-SiO2-Na2O （CSN） based mold flux was studied. The solidification and crystallization properties, including crystallization temperature, crystallization ratio and solidification mineragraphy, were measured, which were compared with the CaO-SiO2-CaF2 （GF） mold flux. The results show that the crystallization performance is equal to the high fluoride mold powder and CSN can be used for peritectic steel grades sensitive to longitudinal cracking in continuous casting.

ORGANOMETALLIC FERROELECTRIC LIQUID CRYSTALS Ⅰ. LIQUID CRYSTAL PROPERTIES OF ORTHO—PALLADATED BINUCLEAR COMPLEXES OF AZINE, IMINE AND AZO DERIVATIVES

The mesomorphie properties of title complexes are investigated by means of DSC and polarizing microscopy. The mesophase temperature ranges of complexes are wider than that of corresponding organic ligands. The bridging groups of the complexes have profoand effects on the mesomorphic behavior, When the bridging groups are opticallhy active. the compleve show chiral smectic

Luminescence Properties and Crystal Growth of Er/Yb Codoped KGd(WO_4)_2

In this paper, the spectral and luminescence properties of a series of KGd（WO4）2 powder samples codoped with different concentrations of Er^3＋ and Yb^3＋ were reported,and the best doping concentrations were found to be lat% Er^3＋ and 10at% Yb^3＋ for attaining the strongest intensity. The Er^3＋/yb^3＋ codoped KGd（WO4）2 crystal with good optical quality was grown by the TSSG method and the growth conditions were presented. The unpolarized absorption and emission spectra of the crystal have been measured. The strong absorption peak is at 980 nm with a FWHM of 65 nm, and the emission peak is at 1536 nm when pumped by 976 rim. The fluorescence lifetime of manifold ^4I13/2 is estimated to be 4.5 ms at room temperature.Investigations of Er, Yb：KGW crystal have shown it to have necessary combination of properties to get an effective generation of - 1.54 μm eye-safe radiation with laser diode pumping.

Synthesis,Structure and Fluorescent Property of a New Isolated Zn6Co9 Heteronuclear Cluster Constructed by Four Kinds of Ligands

A novel zero-dimensional heteronuclear cluster based on N-（phosphonomethyl）imi- no-diacetic acid （H4PMIDA） and Phen （1,10-phenanthroline）, [Zn6Co9（PMIDA）6（Phen）6（NO3）4（H2O）6]·2NO3·16H2O, has been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectrum, thermal analysis, and single-crystal X-ray diffraction. The isolated 15- nuclearity cluster [Zn6Co9（PMIDA）6（Phen）6（NO3）4（H2O）6]^2＋ was constructed by four kinds of ligands, and its charges are balanced by NO3^–. Each isolated cluster is further extended into a 3D supramolecular network through π？？？π interaction and C–H…O hydrogen bonds. Moreover, the solid-state fluorescent property of this complex has also been investigated at room temperature.

Synthesis,Structure,and Property of a Three-dimensional Channel Quaternary Compound:Cs_(0.75(6))Er_(4.43(5))In_(3.32(6))S_(12)

A new quaternary rare-earth sulfide, Cs0.75（6）Er443（5）In3.32（6）S12 （1）, is discovered by high temperature solid state reactions with a slight excess of CsCI flux. The structure is characterized by single-crystal X-ray diffraction data, while crystallizes in hexagonal space group P63/m （No. 176） with a = 12.0329（6）, c = 3.8693（5）A, V= 485.18（7） A3, Z = 1, Mr = 1606.57, Dc = 5.499 g/cm3,μ = 25.457 mm-1, F（000） = 752, the final R = 0.0337 and wR = 0.0904 for 328 observed reflections with I 〉 2σ（I）. Its structure features a three-dimensional framework with hexagonal channels that are centered by Cs cations. Such channels are formed by double chains of edge-sharing M（1）S6 （M（1） = Er（1）/In（1）） octahedra and single chains of Er（2）S6 triprism interconnected by corner-sharing. The syntheses, single-crystal analyses, optical band gap and magnetic property are reported.

Synthesis,Crystal Structure and Properties of a 3-Fold Interpenetrating 3D Cd(Ⅱ)Complex Derived from 4-(2-Methyl-1H-imidazol-1-yl)benzoic Acid

A new Cd~Ⅱ coordination complex,namely [Cd（iba）_2]_n（1）,was prepared by the hydrothermal reaction of Cd（NO_3）_2·4H_2O with 4-imidazol-1-yl-benzoic acid（Hiba）. Single-crystal X-ray diffraction analysis shows that compound 1 crystallizes in monoclinic system,space group Cc with a = 11.403（4）,b = 30.480（9）,c = 7.732（3） ？,β = 130.189（4）o,V = 2503.0（1） ？~3,Z = 4,C_（22）H_（18）CdN_4O_4,Mr = 514.80,Dc = 1.666 g/cm^3,F（000） = 1032 and μ（Mo Kα） = 1.101 mm-1. The final R and wR are 0.0573 and 0.1823 for 4421 observed reflections with I 〉 2σ（I）. Each iba-ligand coordinates in a bidentate fashion,connecting the Cd（Ⅱ） atoms to form a 2D wave-shape layer structure,which can be simplified as a four-connected topological net. Interestingly,the 2D layers are further extended into a 3-fold interpenetrating 3D architecture. Compound 1 displays an emissive maximum at 455 nm in the solid state at room temperature and a response of the second harmonic generation（SHG） activity is approximately 0.8 times that of KDP.

Crystal Structure and Magnetic Properties of a Dinuclear Terbium Compound Tb_2(μ_2-anthc)_4(anthc)_2(1,10-phen)_2

A dinuclear Tb（Ⅲ） compound, Tb_2（μ_2-anthc）_4（anthc）_2（1,10-phen）_2（1, Hanthc = 9-anthracenecarboxylic acid and 1,10-phen = 1,10-phenanthroline）, was synthesized under solvothermal condition and structurally characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the triclinic system, space group P1, with a = 12.5061（12）, b = 13.3168（10）, c = 15.0079（12） ？, α = 110.620（7）, β = 102.941（7）, γ = 107.036（7）o, V = 2081.8（3） ？~3, Z = 1, C_（114）H_（70）N_4O_（12）Tb_2, M_r = 2005.58, D_c = 1.600 g/cm^3, μ = 1.759 mm^（-1）, F（000） = 1008, the final R = 0.0294 and w R = 0.0608 for 8900 observed reflections with I 〉 2s（I）. In compound 1, two Tb（Ⅲ） ions are linked by four carboxylate groups of the bridging anthc– ligands to give a dinuclear Tb_2（μ_2-anthc）_4 unit wherein each Tb（III） ion is further capped by a terminal anthc– ligand and a 1,10-phen ligand in a chelating fashion. Detailed direct-current and alternating-current susceptibility measurements showed no slow magnetism relaxation phenomenon was observed for 1.

Preparation and tensile properties of DD5 single crystal castings

The preparation procedure of DD5 single crystal castings was optimized. The microstructure characteristics of DD5 single crystal superalloy were investigated by microstructure observation and segregation behavior examination. The results show that the grain orientation is optimized by constraining the spiral crystallizer in [001] orientation and spatial scale. Also, the γ＇ phase of inter-dendrites is larger and more irregular than that in dendrite arms. High temperature tensile tests of DD5 single crystal castings exhibit that the peak stress increases with increasing temperature, while the area reduction shows an opposite trend, when the temperature is below 800℃; meanwhile, when the temperature is between 800℃ and 1000℃, the fracture stress of the alloy is the same as the peak stress. The fracture mode changes from shear to ductile with increasing temperature from 600℃ and 1000℃.

Synthesis, Crystal Structure and Characterization of the Host-guest Type UOF

A new uranium（Ⅵ）-polycarboxylate framework with honeycomb（6,3） nets {[Zn（phen）_2（H_2O）_2][（UO_2）_2（BDC）_3]·2H_2O}n（1, BDC = benzene-1,4-dicarboxylate） was hydrotherrmally synthesized by the reactions of Zn（NO_3）_2·6H_2O with phenanthroine, UO_2（NO_3）_2·6H_2O and benzene-1,4-dicarboxylate. The complex was structurally characterized by FT-IR spectroscopy, powder XRD and X-ray single-crystal diffraction. Crystal data for 1： monoclinic, space group Cc with M_r = 1522.19, a = 14.9385（10）, b = 20.4922（13）, c = 15.9728（10） ？, β = 100.1240（10）°, V = 4813.5（5） ？~3, Z = 4, D_c = 2.100 g？cm^（–3）, μ = 7.293 mm^（–1）, F（000） = 2872, the final R = 0.0224 and w R= 0.0677 for 6522 observed reflections with I 〉 2σ（I）. Hydrogen bonds and π-π stacking interactions contribute to the structural extension and stabilization. Experimental band gap of about 3.57 e V indicates its broad gap semiconductor nature. UV-Vis spectra and solid-state luminescence were discussed in detail. The compound exhibits photocatalytic activities for the degradation of rhodamine B.

Optical and defect properties of S-doped and Al-doped GaSe crystals

S-doped and Al-doped GaSe crystals are promising materials for their applications in nonlinear frequency conversion devices. The optical and defect properties of pure, S-doped, and Al-doped GaSe crystals were studied by using photoluminescence（PL） and Fourier transform infrared spectroscopy（FT-IR）. The micro-topography of（0001） face of these samples was observed by using scanning electron microscope（SEM） to investigate the influence of the doped defects on the intralayer and interlayer chemical bondings. The doped S or Al atoms form the SSe^0 or AlGa^＋1） substitutional defects in the layer GaSe structure, and the positive center of AlGa-^＋1 could induce defect complexes. The incorporations of S and Al atoms can change the optical and mechanical properties of the GaSe crystal by influencing the chemical bonding of the layer structure. The study results may provide guidance for the crystal growth and further applications of S-doped and Al-doped GaSe crystals.