Hydrothermal Synthesis, Crystal Structure and Thermal Analyses of Pyrazine-2,3-dicarboxylic Acid Bridged Co(II) Coordination Polymer of _∞~2[Co(phen)(μ-L)_(3/3)]·H_2O (H_2L = Pyrazine-2,3-dicarboxylic Acid)

A novel pyrazine-2,3-dicarboxylic acid bridged Co(II) phen complex 2 ∞ [Co- (phen)(μ-L)3/3]?H2O (H2L = pyrazine-2,3-dicarboxylic acid) has been hydrothermally synthesized, and X-ray single-crystal diffraction analysis shows that it crystallizes in the monoclinic system, space group P21/n with a = 11.480(2), b = 11.885(2), c = 12.939(3) ?, β = 110.55(3)°, V = 1653.1(6) ?3, Mr = 423.25, Dc = 0.425 g/cm3, Z = 4, R = 0.0361 and wR = 0.1011. The title complex consists of 2D 2 ∞ [Co(phen)(μ-L)3/3] layers and crystal water molecules. Each Co atom is octahedrally coordinated by three N atoms and three O atoms to form 2D 2 ∞ [Co(phen)(μ-L)3/3] polymeric layers. Furthermore, such 2D layers are stacked into 3D supramolecular frameworks via Van der Waals’ intermolecular forces, strong and weak hydrogen-bond interactions. The coordination phen and crystal water molecules are resided into cavities of the frameworks.

Hydrothermal Synthesis,Crystal Structure and Fluorescence Spectrum Studies of a Novel Supramolecular Compound {[2-(2-Pyridyl)benzimidazoleH_2]_2·[BiCl_6]·Cl}

A novel supramolecular compound,{[2-（2-pyridyl）benzimidazoleH2]2·[BiCl6]·Cl},was synthesized by the hydrothermal reaction of o-phenylenediamine and α-pyridinecarboxylic acid with BiCl3 in 6.0 mol·L-1 HCl solution,and characterized by elemental analysis,IR,X-ray single-crystal diffraction and photoluminescence spectroscopy.The crystal （C24H22N6Cl7Bi,Mr= 851.61） belongs to the triclinic system,space group P1 with a =7.2887（18）,b =9.548（2）,c= 12.469（3）,α=85.306（4）,β=82.814（4）,γ=71.349（4）°,Z=1,V=814.9（3）3,Dc=1.735 g/cm3,μ（MoKα）=6.007 mm-1,F（000）=410,R=0.0307 and wR=0.0787.The bismuth ion and six chlorine ions construct a distorted octahedral configuration.The three-dimensional supramolecular network is built from electrostatic attractions,hydrogen bonds and π-π interaction between the BiCl6 anion,Cl anion and [2-（2-pyridyl）benzimidazoleH2] cation.The photoluminescence spectroscopy study shows that the title compound has a blue fluorescent emission at 450 nm in the solid state.

Syntheses and Structural Characterizations of a Series of Capped Keggin Derivatives

Hydrothermal reactions of Na2MoO2·2H2O and NH4VO3（or V2O5） with appropriate reducing agents such as organic amines, NH2OH·HCl and Mo（CO）6 gave rise to the formation of a series of capped Keggin derivatives, [N（CH3）4]2Na3（NH4）2[（V^VO4）Mo^VI8V^IV4O36（V^IVO）2]·-13H2O（1）, [NH4]7[（V^VO4）Mo^VI8V^IV4O36（V^IVO）2]·7H2O（2）, [HN（CH2CH2）3NH][（PO4）Mo^V3Mo^VI9O36（V^IVO）2]·-3[N（CH2CH2）3N]·（en）·4.5H2O（3） and [HNH2OH][NH4]2[（V^VO4）Mo^VI8V^IV4O36（V^IVO）4]·24H2O（4）. Single-crystal X-ray diffraction analysis revealed that the anions in 1-3 are two-capped Keggin derivatives with characteristic trans vanadium-oxygen caps, whereas the heteropoly anion in 4 is a tetra-capped α-Keggin derivative with characteristic vanadium-oxygen caps on the equatorial plane.

Microwave-assisted Hydrothermal Synthesis of Carbon Materials with Tunable Microstructure

A facile microwave-assisted hydrothermal route has been developed for a synthesis of versatile carbon materials. The monosaccharide fructose aqueous solution was adopted as the starting material, and the p H of the solution was adjusted to be in acidic（pH 4）, neutral（pH 7） and basic（pH 10.5） conditions. The p H buffered fructose solutions were treated at different temperatures by a microwave-assisted hydrothermal technique. As-prepared carbon materials displayed p H and temperature dependent multi-morphologies（porous, spherical or core-shell）, which were determined by transmission and scanning electron microscopic analyses（TEM and SEM）. And the hypothesis of dehydration mechanism of hydrothermal synthesis was analyzed by ultraviolet extinction and Fourier transform infrared spectroscopy. It was found that as compared with normal hydrothermal synthesis, microwave assistance could efficiently increase the production yield and improve the spherical geometry of the carbon particles in neutral condition. By changing the p H of the system, acidic p H induces aggregation of the spheres, while basic p H produces more trends toward core-shell or sponge-like porous structure. The study opens a novel route to the production of polytropic carbon materials and suggests a potential niche market established from the green synthesis.

Mild Hydrothermal Synthesis,Crystal Structure and Magnetic Behavior of AgCu(IO_3)_3:a Quasi-one-dimensional S=1/2 Chain Compound

A new complex AgCu（IO3）3 is synthesized by mild hydrothermal method and characterized by single-crystal X-ray diffraction and magnetization measurement.AgCu（IO3）3 is triclinic,space group P1,with a = 7.3081（1）,b = 7.8089（1）,c = 8.2447（1）A,α = 67.159（1）,β = 74.982（1）,γ = 80.982（1）°,and Z = 2.AgCu（IO3）3 is isostructral with Ag Pb（IO3）3.The structure of Ag Cu（IO3）3 consists of CuO6 chain columns parallel to the c axis,formed by corner-sharing Cu（1） and Cu（2） octahedra and flanked by corner-sharing IO3 groups; these CuO6 columns are cross-linked into a three-dimensional framework through I–O and Ag–O bonds.I（1）,I（2） and I（3） are coordinated respectively with 3 oxygens on the same side to form trigonal pyramids confirming the presence of a stereochemically active lone pair of each I^5＋ cation.In the CuO6 chain columns,Cu（1）O6 and Cu（2）O6 octahedra are tetragonally distorted with four shorter bonds in the square planes and two longer apical bonds.Cu（1）O6 octahedra were corner sharing with Cu（2）O6 octahedra with a shorter Cu（1）–O（1） bond in the square planes and a longer apical Cu（2）–O（1） bond,which forms a Cu（1）–Cu（2） magnetic chain along the c direaction.Magnetization measurement shows weak antiferromagnetic property in low temperature range.Ag Cu（IO3）3 provides a new example of a quasi-one-dimensional magnetic system.

Hydrothermal Syntheses and Crystal Structures of Two Complexes with Cyclic Dimer and 2D Network Structures of 3-Nitrophthalate and N-Donor Ligand

Two complexes, [Cd（nphth）（2,2＇-bipy）（H20）]2.2H20 （1） and [Cd（nphth）（4,4＇- bipy）（H20）], （2） （nphth = 3-nitrophthalate, 2,2＇-bipy = 2,2＇-bipyridine, 4,4＇-bipy = 4,4＇-bipyridine）, were synthesized by hydrothermal reactions and structurally characterized. Complex 1 crystallizes in triclinic with space group Pi, a = 0.7599（4）, b = 1.0551（6）, c = 1.2448（6） nm, α = 88.96（2）, β = 75.40（2）, γ= 76.76（2）°, V= 0.9393（9） nm3, Z = 1, Dc = 1.816 Mg/m3, F（000） = 512, μ = 1.217 mm-1, S = 0.946, the final R = 0.0238 and wR = 0.0631, Complex 2 crystallizes in monoclinic, space group P21/c, a = 0.737（5）, b = 2.338（1）, c = 1.0030（6） nm, β = 96：359（9）°, V= 1.803（2） nm3, Z = 4, Dc = 1.826 Mg/m3, F （000） = 984,μ = 1.260 mm-1, S = 1.016, the final R = 0.0455 and wR = 0.1007. Complex 1 exhibits a discrete cyclic binuclear structure and complex 2 possesses a 2D layer structure with cyclic binuclear unit. The fluorescent spectrum study shows that complex 1 exhibits fluorescent emission in the solid state at room temperature.

Magnetite-Fluorite Rock:A New Rock Type of Hot Water Sedimentation

The new type hot water sedimentary rock -- magnetite-fluorite rock occurs as quasi-layers in flat parts of contact zones between rock body and strata in Bamianshan of Changshan County, Zhejiang Province, China. The main mineral assemblage is fluorite＋magnetite＋cassiterite. The rock shows typical laminated structure and obvious mosaic texture. Its formation temperature is between 123℃-160℃, averaging at 142℃. The major chemical composition of the rock includes CaF2, SiO2, Al2O3, FeO, and Fe2O3; the high-content microelement association includes W, Sn, Be, Rb, Sr, S, and CI; and the total content of REE is low （∑REE between 35.34×10^-6-38.35×10^-6）, showing LREE enrichment type of distribution pattern. Diagenesis： driven by the tectonic stress, the formation water heated in the deep strata had moved along the fissures or fractures in strata and had extracted components from the strata on the way, and finally stagnated in the flat parts of contact zones between rock body and strata. With drop in temperature, magnetite and fluorite were separated from the hot water and precipitated alternately, forming this hot water sedimentary rock with new type mineralogical composition, typical laminated structure, obvious mosaic texture and sub-horizontal occurrence. The characteristics of the new type mineralogical composition, sedimentary tectonic environment and chemical composition are different from that of the well-known traditional hydrothermai sedimentary rocks.

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.

A Metal-organic Framework Containing Octanuclear Zn(Ⅱ) Clusters Constructed by 5-Methoxyisophthalate and Flexible Bis(imidazolyl) Ligand

The hydrothermal reaction of 5-methoxyisophthalic acid（MeO-H2ip）, 1,3-bis（2-methylimidazol-1-yl）propane（bmip） and Zn（NO3）2·6H2O in the presence of NaOCH3 gave rise to a three-dimensional（3-D） metal-organic framework containing octanuclear Zn（II） units, [Zn4（MeO-ip）3（OH）2（bmip）]n. Single-crystal X-ray diffraction analysis reveals that the complex crystallizes in the triclinic space group P1 with a = 11.348（3）, b = 14.163（4）, c = 15.088（4） , α = 108.537（2）, β = 106.542（2）, γ = 103.106（1）o, V = 2065.4（9） -3, Z = 2, Mr = 334.62, Dc = 1.740 g·cm-（-3）, μ = 2.375 mm-（-1）, S = 1.015, F（000） = 1096, the final R = 0.0272 and w R = 0.0715 for 8929 observed reflections（I 〉 2σ（I））. The complex is thermally stable up to 370 oC, and exhibits photoluminescent emission at 450 nm on 350 nm excitation.

Fluorescence Properties and Crystal Structures of Metal-organic Coordination Complexes Based on the 2,6-Naphthalenedicarboxylic Acid

Two metal-organic coordination complexes, [Zn（2,6-ndc）（1,2-bix）]n（1） and [Zn（2,6-ndc）（1,3-bix）]n（2）（2,6-H2ndc = 2,6-naphthalenedicarboxylic acid, 1,2-bix = 1,2-bis（imidazole-1-ylmethyl）-benzene and 1,3-bix = 1,3-bis（imidazole-1-ylmethyl）-benzene） have been synthesized by the hydrothermal method. Though the two complexes both crystallize in a triclinic system, space group P1 and show similar two-dimensional structures, weak intermolecular interactions（π-π packing interactions） only exist in complex 2. They are characterized by single-crystal X-ray diffraction analysis, fluorescence measurement, IR spectroscopy and TGA. Moreover, the solid-state fluorescence spectra of two complexes show maximal emission peaks at 365（λ（ex） = 329 nm） and 367 nm（λex = 344 nm）, respectively.

Synthesis,Crystal Structure and Fluorescent Properties of Silver and Cadmium Complexes

Two new complexes [Ag（bix）]n·n NAA·n H2O（1） and [Cd（NAA）（phen）2（H2O）]2· 2CH3COO-·H2O（2）（bix = 1,4-bis（imidazol-1-ylmethyl）benzene,HNAA = α-naphthylacetic acid,phen = 1,10-phenanthroline） have been successfully synthesized under hydrothermal conditions.Their structures have been determined by elemental analyses,IR spectroscopy,TG and single-crystal X-ray diffraction analysis.The intermolecular hydrogen bonding or π-π stacking interactions extend the complexes into a 3D supramolecular structure.Moreover,the luminescent properties of complex 2 have been investigated in the solid state.

Synthesis and Characterization of a One- dimensional Molybdenum Oxide (H_2enMe)[Mo_3O_(10)]

A hybrid organic-inorganic material （H2enMe）[Mo3O10] （C3H12Mo3N2O10, Mr = 523.97） has been synthesized under hydrothermal conditions and its crystal structure was determined by X-ray diffraction. It crystallizes in the orthorhombic system, space group Pnma with a = 12.430（2）, b = 7.6089（12）, c = 11.9553（19）A , V = 1130.7（3）A^3, Dc = 3.078 g/cm^3, Z = 4, μ（MoKa） = 3.328 mm^-1, F（000） = 1000, the final R = 0.0256 and wR = 0.0716 for 1314 observed reflections with I 〉 2σ（I）. A total of 11780 reflections were measured and 1325 were unique （Rint = 0.0244）. It consists of infinite one-dimensional edge-sharing MoO6 octahedral chains with [Mo3O10]^2- moieties. The protonated diaminopropane cations are located between the chains and linked to the oxygen atoms of the inorganic skeletal backbones by hydrogen bonds. It is indicated that the as-synthesized compound displays photochromic property in the solid state.

Pd catalysts supported on rGO-TiO_2 composites for direct synthesis of H_2O_2: Modification of Pd^(2+)/Pd^0 ratio and hydrophilic property

The use of nanostructured composites as catalyst supports is a promising route to prepare catalysts with high selectivity and productivity. In this work, reduced graphene oxide-TiO_2(rGP-x) composites with a variation of reduced graphene oxide(rGO) content were synthesized by hydrothermal method. Pd/rGP-x catalysts were prepared in incipient-wetness impregnation method for the direct synthesis of H_2O_2 from H2 and O_2. The morphology and electronic properties of catalysts were investigated by XPS, TEM, and Raman spectroscopy.The ratio of Pd^(2+)/Pd^0 and the hydrophobicity of the catalysts were increased with the rising content of rGO. As the amount of rGO in the catalysts varied in the range of 0.025 wt%–2 wt%, the selectivity of H_2O_2 exhibited a tendency of increasing firstly and then decreasing from 0.1 wt% to 2 wt%. It indicates that good catalytic performance for H_2O_2 synthesis can be achieved only when appropriate amount of rGO is introduced. The H_2O_2 selectivity and productivity of Pd/r GP-0.025 both improved remarkably compared with Pd/P25. This enhancement originated from the combined effects of the proper ratio of Pd^(2+)/Pd^0 and hydrophobicity of the catalyst.

A New Organic-inorganic Hybrid Arsenatotungstate[{Cu(phen)(en)}{Cu(phen)}{Cu_3(phen)_3(α-AsW_9O_(33))}](OH)·3H_2O

A new organic-inorganic hybrid copper-substituted arsenatotungstate complex formulated as [{Cu（phen）（en）} {Cu（phen）} {Cu3（phen）3（α-AsW9033）}]（OH）·3H2O （1, en = ethylene-diamine, 1,10-phen = 1,10-phenanthroline） has been synthesized by controlling the reaction process and characterized by infrared （IR） spectroscopy, elemental analysis, and thermogravimetric （TG） analysis. Crystal data for 1： C62H56AsCusN12O37W9, Mr=3608.46, monoclinic, space group P21/n, a = 13.245（4）, b = 25.692（9）, c = 24.670（8） A, fl = 99.251（6）°, V= 8286（5） A3, Z = 4, GOOF = 1.103, R = 0.0560, wR = 0.1285. In 1, the vacant sites of the trivacant Keggin anion [α-AsW9O33]9- are occupied by three same copper coordination cations [Cu（phen）]2＋. Meanwhile, the lacunary anion [α-AsWgO33]9-, is capped by two kinds of copper coordination cations [Cu（phen）]2＋ and [Cu（Dhen）（en）]2＋, resulting in an unorecedented Dolvcation structure with Cs svmmetrv.

Synthesis,Structure,and Magnetic Properties of a New Cobalt Selenite Ca_2Co(HSeO_3)_2(SeO_3)_2

A new cobalt selenite,Ca_2Co（HSeO3）_2（SeO_3）_2,was synthesized by a conventional hydrothermal method. Single-crystal X-ray diffraction analysis reveals that Ca_2Co（HSeO3）_2（SeO_3）_2 crystallizes in triclinic system,space group P1,with a = 5.330（5）,b = 7.047（7）,c = 8.457（9） ？,V = 285.0（5） ？~3,Z = 1,Mr = 646.93,Dc = 3.769,μ = 15.235 mm^（-1）,F（000） = 299.0,the final R = 0.0452 and wR = 0.1169 for observed 1265 reflections with I 〉 2σ（I）. The title compound consists of isolated chains built from CoO_6 octahedra and SeO_3 pyramids. In this structure,the chains are separated by Ca^（2＋） cations. Magnetic measurements confirm that the title compound exhibits long-range antiferromagnetic ordering at 3 K and field-induced magnetic transition at 2 T.

Synthesis, Crystal Structure and Theoretical Calculations of a New Two-dimensional Co(Ⅱ) Coordination Polymer Based on Oxalic Acid and Bis(imidazol) Ligands

A new Co（ll） coordination polymer has been successfully synthesized under hydrothermal conditions [Co（C2O4）（mbix）]n （1, H2C2O4 = oxalic acid, mbix = 1,3-bis（imidazol- l-ylmethyl）benzene）. Its structure has been determined by elemental analyses, IR, UV spectroscopy and single-crystal X-ray diffraction analysis. Pink crystals crystallize in the triclinic system, space group PI with a = 8.8666（7）, b = 9.5859（8）, c = 10,8537（9） A,α = 67.6810（10）,β= 66.1260（10）, γ = 77.1300（10）°, V= 777.77（11）, CI6HI4CoN404, Mr = 385.24, Dc = 1.645 g/cm3, F（000） = 394, Z= 2,/z（MoKa） = 1.134 mm% the final R = 0.0482 and wR = 0.1231 for 2968 observed reflections （I〉 2σ（I））. It shows a two-dimensional （2D） network structure. The intermolecular C-H…O hydrogen bonding and π-π stacking interactions extend complex 1 into a 3D supramolecular architecture and play an important role in stabilizing 1. In addition, Natural Bond Orbital （NBO） analysis was performed by using the PBE0/LANL2DZ method built in Gaussian 09 Program. The calculation results showed obvious covalent interaction between the coordinated atoms and Co（II） ion.

Insight into the formation of hollow silver nanoparticles using a facile hydrothermal strategy

A facile hydrothermal approach is used to synthesize hollow silver nanoparticles, labeled as hAgNPs, involving an initial formation of metal complexes from Ag＋ ion precursors and dodecylamine in a water]ethanol mixture at room temperature and a subsequent reduction in an autoclave at elevated temperature. A number of characterization techniques are used to characterize the structure and chem- ical composition of the as-formed hAgNPs, and to understand the mechanism behind the formation, The notable simplicity renders this synthetic approach promising for creating hAgNPs on a large scale for a given technological application, and the mechanistic understanding may provide new opportunities to design and fabricate other hollow nanostructures.

CO sensing properties of a cubic ZnSn(OH)_6 synthesized by hydrothermal method

In this work, ZnSn（OH）6with a cubic structure is successfully synthesized by one-step hydrothermal method without any catalyst. The response and recovery characteristics of gas sensing were investigated against various gases via quartz crystal microbalance（QCM） at room temperature. The sensor exhibited high sensitivity and good selectivity toward CO gas. Moreover, a linear dependence of log^（àDelta F）about CO concentration was obtained. It is demonstrated that the QCM sensor coated cubic ZnSn（OH）6could be a suitable candidate for detecting CO.

Microwave-assisted solvothermal synthesis of ZSM-22 zeolite with controllable crystal lengths

ZSM-22 （TON） zeolite crystal morphology was successfully controlled using a microwave-assisted solvothermal fabrication method. Different co-solvents, including ethanol, 2-propanol, glycerol, and ethylene glycol, were also applied in the synthesis mixture. The effects of various parameters such as the aging time, the type and amount of co-solvent on the ZSM-22 crystal aspect ratio were investigated. When employing this microwave irradiation synthesis, a long aging time was crucial to obtain smaller and more uniform crystal sizes. The addition of co-solvent resulted in elongated ZSM-22 crystals, regard- less of the actual co-solvent used, although ZSM-22 zeolite crystallinity was sensitive to the co-solvent type. In general, the use of a co-solvent stimulated the appearance of ZSM-5 zeolite as an impurity and the amount of this impurity was proportional to the concentration of co-solvent in the synthesis mixture.

Synthesis,Structure and Photoluminescence of Two Zinc Carboxylate Polymers with Different Coordination Architectures

The hydrothermal reaction of ZnO with benzene 1,4 dicarboxylic acid gave Zn·BDC·2H 2O (1) and Zn·BDC·H 2O (2) (BDC=benzene 1,4 dicarboxylate), respectively. Polymer 1 (C 4H 4O 3Zn 0.5 ) shows a one dimensional zigzag chain structure built up from the alternate connection of tetrahedral ZnO 4 and BDC units. Polymer 2 (C 4H 3O 2 5 Zn 0 5 ) possesses a three dimensional framework containing infinite zigzag Zn···Zn···Zn pseudochains generated by five coordinate zinc centers and a rectangular channel system including three groups of different straight channels along the [001], [010] and [60 1] directions. The two metal organic polymeric compounds exhibit strong photoluminescent emission bands at 402 nm ( λ ex =260 nm) (for 1) and at 344 nm and 385 nm ( λ ex =279 nm) (for 2) in the solid state at room temperature.