Crystal structure, thermal decomposition mechanism and explosive properties of [Na(H2TNPG)(H2O)2]n

The new coordination polymer of sodium trinitrophloroglucinate, [Na(H2TNPG)(H2O)2]n, was synthesized by reacting trinitrophloroglucinol (H3TNPG) with NaHCO3 in aqueous solution and [Na(H2TNPG)(H2O)2]n was recrystallized to be yellow single crystal. The title compound was characterized by using elemental analysis and Fourier transform infrared (FT-IR) spectrum. Its crystal structure was determined by single crystal X-ray diffraction analysis. The crystalline belongs to monoclinic system and C2/c space group. Each Na+ ion is six-coordinated to one H2TNPG- anion and four water molecules in which the oxygen atoms in the water molecules act as bridging atoms. Coordination bonds, electrostatic interaction and intermolecular hydrogen bonds assemble the ions into network structures. The thermal decomposition mechanism of the complex was studied by using differential scanning calorimetry (DSC), thermogravimetry/derivative thermogravimetry (TG/DTG) and FT-IR techniques. Under nitrogen atmosphere with a heating rate of 10 degrees C/min the thermal decomposition of the complex contained one endothermic and five exothermic processes. Two intense exothermic decomposition processes were observed in the range of 173-228 degrees C suggesting its energetic nature and the solid decomposition residue at 500 degrees C was sodium isonitrile. Explosive properties revealed that the compound is sensitive to mechanical stimuli. All properties data observed show that the title compound has explosive properties and can act as components of ecologically clean initiating compositions.     

Studies on three-dimensional coordination polymer [Cd2(N2H4)2(N3)4]n: crystal structure, thermal decomposition mechanism and explosive properties

A 3D coordination polymer of cadmium(II) hydrazine azide, [Cd2(N2H4)2(N3)4]n, was synthesized and characterized by elemental analysis and Fourier transform infrared (FT-IR) spectrum. Its crystal structure was determined by single crystal X-ray diffraction analysis. The crystal belongs to monoclinic, P2(1)/c space group, a=12.555(2)A, b=11.724(2)A, c=7.842(1)A, beta=94.56(2) degrees and Z=4. The crystal contains two crystallographically independent sets of distorted octahedral Cd(II) atoms and dimeric units of Cd2N2, Cd2(NNN)2, Cd2(NN)2 through double micro-1, 1 azide bridges, micro-1, 3 azide bridges and bidentate bridging hydrazine ligands, respectively, and thus generating a 3D network structure. The thermal decomposition mechanism of the complex was studied by using differential scanning calorimetry (DSC), thermogravimetry-derivative thermogravimetry (TG-DTG) and FT-IR techniques. Under nitrogen atmosphere with a heating rate of 10 degrees C/min, the thermal decomposition of the complex contained two intense exothermic decomposition processes in the range of 150-304 degrees C in the DSC curve, and the final decomposed residue at 500 degrees C was Cd. Sensitivity tests revealed that the title complex is very insensitive to external stimuli.     

Crystal Structure of K[UO2(NO3)3] and Some Features of Compounds M[UO2(NO3)3] (M = K,Rb, and Cs)

Greenish-yellow transparent crystals of K[UO₂(NO₃)₃] were prepared from aqueous solutions as by-product in synthesis of potassium chromatouranylates. The crystal structure was solved by the direct methods and refined to R ₁ = 0.037 (wR ₂ = 0.070) for 1452 reflections with |F _hkl| 4|F _hkl|. Mono- clinic system, space group C2/c, a = 13.4877(10), b = 9.5843(7), c = 7.9564(6) Å, = 116.124(2)°, V = 923.45(12) ų. The structure of K[UO₂(NO₃)₃] contains isolated complex ions [UO₂(NO₃)₃]^- whose uranyl groups are aligned parallel to the [-101] plane. The K⁺ cations, coordinated by twelve oxygen atoms, are located between the complex anions. Comparison of the structure with known data on M[UO₂(NO₃)₃] compounds (M = K, Rb, Cs) suggests the possibility of phase transitions due to relatively small displacements of [UO₂(NO₃)₃]^- anions and K⁺ cations, retaining the general structural motif.     

{[Cd(Ⅱ)L(NCS)2](DMF)2}n(L=1,4-二[2-(2-吡啶基)苯并咪唑基]丁烷)的合成,晶体结构与荧光光谱研究

合成了一种新的包含咪唑基团的双端四齿鳌合配体1,4-二[2-(2-吡啶基)苯并咪唑基]丁烷,并用其作为桥联配体与金属离子共同构筑配位聚合物.用Cd2 金属离子和L在DMF/H2O混合溶液中,存在KSCN的条件下,合成一种新型的一维链状配位聚合物{[Cd(Ⅱ)L(NCS)2](DMF)2}n(L=1,4-二[2-(2-吡啶基)苯并咪唑基]丁烷).单晶X-射线分析仪分析表明,该晶体属三斜晶系,P-1空间群,晶胞参数为:a=8.869(1)A,b=11.278(2)A,c=19.328(4)A,α=89.83(3)°,β=89.52(3)°,γ=74.28(3)°,V=1860.9(7)(A)3,Z=2,7250个独立衍射点中,6039个可观测点满足F2≥2σ(F2o),R=0.0543,wR2=0.1442.它是由一维的锯齿形链[Cd(Ⅱ)L(NCS)2]n和游离的DMF分子组成.在链内金属原子与来自于2个具有不同结构的配体L中的4个N原子和2个SCN-阴离子中的2个N原子形成八面体配位.该固态配合物在室温下用389nm的紫外光激发时在453nm处发射出强的荧光.     

Synthesis and Crystal Structure of Cs4[UO2(CO3)3]

Light green transparent crystals of Cs₄[UO₂(CO₃)₃] were prepared by evaporation from aqueous solutions. The crystal structure was refined to R ₁ = 0.039 (wR ₂ = 0.081) for 2311 reflections with |Fhkl| 4|Fhkl|. Monoclinic system, space group C2/c, a = 11.5131(9), b = 9.6037(8), c = 12.9177(10) Å, = 93.767(2)°, V = 1425.2(2) ų. The structure of Cs4[UO2(CO3)3] consists of isolated complex ions [UO₂(CO₃)₃]^{4 -} formed by uranyl cation UO₂ ^{2 +} and three CO₃ ^{2 -} groups. The equatorial planes of the [UO₂(CO₃)₃]^{4 -} ions are approximately parallel to the (201) plane. The nine-coordinate Cs⁺ cations are located between the complex anions. The compound is isostructural with M4[UO2(CO3)3] with M = K, NH₄, and Tl, but not isostructural with Na₄[UO₂(CO₃)₃].     

Synthesis, structural investigation, thermal decomposition mechanism and sensitivity properties of an energetic compound [Cd(DAT)(6)](ClO(4))(2) (DAT=1,5-diaminotetrazole)

An energetic coordination compound [Cd(DAT)(6)](ClO(4))(2) has been synthesized by using 1,5-diaminotetrazole (DAT) as ligand and its structure has been characterized by applying X-ray single crystal diffraction, elemental analysis and FT-IR spectroscopy. The central cadmium(II) cation is coordinated by six N atoms from six DAT molecules to form a six-coordinated and distorted octahedral structure. Di-dimension layer structure was formed and the layers were linked together by the extensive intermolecular hydrogen bonds between DAT ligands and ClO(4)(-) anions. Thermal decomposition mechanism of the title compound was predicted based on DSC, TG-DTG and FT-IR analyses results. The kinetic parameters of the first exothermic process of the title compound were studied by applying the Kissinger's and Ozawa-Doyle's methods. Sensitivity tests reveal that the title compound has sensitive nature.     

Crystal structure of Rb3[UO2(CH3COO)3]2[UO2(CH3COO)(NCS)2(H2O)]

The structure of Rb₃[UO₂(CH₃COO)₃]₂[UO₂(CH₃COO)(NCS)₂(H₂O)] was studied by single crystal X-ray diffraction. The compound crystallizes in the monoclinic system with the unit cell parameters (at 100 K) a = 18.387(3), b = 16.398(3), c = 12.460(2) Å, β = 92.837(5)^°, V = 3752.4(11) ų, space group C2/c, Z = 4, R = 0.0390. The uranium-containing structural units of the crystals are isolated mononuclear groups [UO₂(CH₃COO)₃]^? and [UO₂(CH₃COO)(NCS)₂(H₂O)]^?, belonging to crystal-chemical groups AB ₃ ⁰¹ and AB⁰¹M ₃ ¹ (A = UO ₂ ²⁺ , B⁰¹ = CH₃COO^?, M¹ = NCS^? and H₂O) of uranyl complexes, respectively. The uranium-containing complexes are linked in a framework by hydrogen bonds and by electrostatic interactions with Rb⁺ cations.     

Synthesis, structure, and properties of [Be(H2O)4][UO2(CH3COO)3]2

Crystals of previously unknown compound [Be(H₂O)₄][UO₂(CH₃COO)₃]₂ were prepared and studied by X-ray diffraction analysis. The compound crystallizes in the tetragonal system, unit cell parameters (at 100 K): a = 10.3647(3), c = 23.4127(8) Å, V = 2515.16(13) ų, space group I4₁/a, Z = 4, R = 0.0194. The structure consists of mononuclear complexes [Be(H₂O)₄]²⁺ and [UO₂(CH₃COO)₃]^? linked with each other by electrostatic interactions and hydrogen bonds formed by water molecules and O atoms of acetate anions. The compound was also studied by methods of thermal analysis and IR spectroscopy.     

Phase diagrams of the ternary liquid systems [Ce(NO3)3(TBP)3]-C10H22-[UO2(NO3)2(TBP)2] and [Ce(NO3)3(TBP)3]-C10H22-[Th(NO3)4(TBP)2] and of the quaternary liquid system [Ce(NO3)3(TBP)3]-C10H22-[UO2(NO3)2(TBP)2]-[Th(NO3)4(TBP)2]

The phase diagrams of the ternary liquid systems [Ce(NO₃)₃(TBP)₃]-C₁₀H₂₂-[UO₂(NO₃)₂(TBP)₂] and [Ce(NO₃)₃(TBP)₃]-C₁₀H₂₂-[Th(NO₃)₄(TBP)₂] and of the quaternary liquid system [Ce(NO₃)₃(TBP)₃]-C₁₀H₂₂-[UO₂(NO₃)₂(TBP)₂]-[Th(NO₃)₄(TBP)₂] at T = 298.15 K are constructed. The phase diagrams are characterized by areas of homogeneous solutions and of two-phase liquid systems (systems with phase separation), with one phase (I) enriched in [Ce(NO₃)₃(TBP)₃], [Th(NO₃)₄(TBP)₂], and [UO₂(NO₃)₂(TBP)₂], and the other phase (II), in C₁₀H₂₂. Using the data on the mutual solubility of the components in the systems under consideration and equations of the NRTL model, the parameters of intermolecular interactions and the excess Gibbs energies (G ^ex) were calculated for the binary, ternary, and quaternary systems. Passing from the ternary system [Ce(NO₃)₃(TBP)₃]-C₁₀H₂₂-[Th(NO₃)₄(TBP)₂] to the quaternary system [Ce(NO₃)₃(TBP)₃]-C₁₀H₂₂-[UO₂(NO₃)₂ (TBP)₂]-[Th(NO₃)₄(TBP)₂] does not appreciably affect the distribution of C₁₀H₂₂ between phases I and II, but leads to the redistribution of [Ce(NO₃)₃(TBP)₃] into phase II and of [Th(NO₃)₄(TBP)₂] into phase I.     

Thioether crown complexes as templates for the assembly of extended polyiodide networks: synthesis and structures of {[M([16]aneS4)]2I}I11 (M = Pd,Pt), [Pd(cis-HO)2[14]aneS4)](I3)2, [Pd([9]aneS3)2](Ix)2 (x = 3, 5)

Pd(II) and Pt(II) complexes of [16]aneS₄ and Pd(II) complexes of cis-(HO)₂[14]aneS₄ and [9]aneS₃ have been used as templates for the self-assembly of polyiodide ions. The complexes {[M([16]aneS₄)]₂I}I₁₁ (M = Pd, Pt), [Pd(cis-(HO)₂[14]aneS₄)](I₃)₂, [Pd([9]aneS₃)₂](I_x)₂ (x = 3, 5) have been synthesized and structurally characterized. In {[M([16]aneS₄)]₂I}I₁₁, the polyiodide network consists of fused 14-member polyanion rings made up of interacting “L”-shaped I₅⁻ and I⁻ units; binuclear [([16]aneS₄)M–I–M([16]aneS₄)]³⁺ complex cations featuring a highly unusual linear and symmetric M–I–M moiety are each surrounded by one of these 14-member polyiodide rings in a belt-like fashion. The structures of [Pd(cis-(HO)₂[14]aneS₄)](I₃)₂ and [Pd([9]aneS₃)₂](I₃)₂ both feature tri-iodides as counter-anions. In [Pd(cis-(HO)₂[14]aneS₄)](I₃)₂, quite asymmetric I₃⁻ ions form sinusoidal infinite chains via head-to-tail I₃⁻⋯I₃⁻ interactions; these chains run along the (001) direction and are stacked along the (100) direction to form highly puckered anionic layers via I⋯I weak interactions that cross-link the chains. In [Pd([9]aneS₃)₂](I₃)₂, [Pd([9]aneS₃)₂]²⁺ cations are bridged on each side by pairs of symmetric I₃⁻ ions through long-range S⋯I contacts to form discrete infinite ribbons that run parallel to the a axis. By contrast, the structure of [Pd([9]aneS₃)₂](I₅)₂ consists of highly puckered polyanionic layers featuring fused 18-member polyiodide rings made up of I₅⁻ ions. Two of these layers related by an inversion center are stacked along the b axis and interact with each other to form large cavities within which the complex cations sit. In these complex arrays the cation can be regarded as a template around which polyanion networks can be structured. The solid state FT-Raman spectra of the reported polyiodides are discussed on the basis of their crystal structures.     

The Effect of Nitrogen Pressure on the Synthesis of CdS From [Cd(NH2C(S)NHNH2)2](NO3)2 Complex Compound Using Combustion Method

A precursor method of obtaining sulfide materials by combustion of metal nitrate complex compounds with sulfur-containing organic derivatives of hydrazine as ligands has been proposed. A possibility of maintaining morphology and dispersity of the obtained products by changing external pressure at which the combustion is carried out has been demonstrated for the synthesis of cadmium sulfide as an example.     

Crystal Structure of Rb[UO2(SO4)F]

Single crystal of Rb[UO₂(SO₄)F] (I) was studied by X-ray diffraction [rhombic system, space group Pca2 ₁, Z = 12, unit cell parameters: a = 25.393(3), b = 6.735(1), c = 11.496(3) Å]. The main structural units of crystals of I are [UO₂(SO₄)F]^- layers belonging to the crystallochemical group AT³M² (A = UO₂ ^{2 +}) of uranyl complexes and combined into three-dimensional framework by electrostatic interactions involving interlayer rubidium ions.     

Giant Magnetoresistance Effect of [bcc-Fe(M)/Cu](M=Co,Ni) Multilayers

1. IlltroductionGiant magnetoresistance (GMR) effect of metallic multilayers has been widely investigated after thefinding by Baibich et al.11], as a new phenomenon tobreak through the memory density in ultra high density magnetic recording, high sensitivity in magnetichead, and so on. Metallic multilsyers of 3d transition elements could be classified into three groups of[bee/bcc], [fee/fccl and [bee/fcc] from the standpointof combination of crystal structure of constituting elements of metal…     

Physicochemcial analysis of the phase diagram of the ternary liquid system [Y(NO3)3(TBP)3]-tetradecane-[UO2(NO3)2(TBP)2]

The phase diagram of the ternary liquid system (TLS) [Y(NO₃)₃(TBP)₃]-tetradecane-[UO₂ · (NO₃)₂(TBP)₂] (TBP is tri-n-butyl phosphate) at 298.15 K is constructed. The TLS is characterized by an area of homogeneous solutions and an area of two-phase liquid systems with one of the phases (I) enriched in [Y(NO₃)₃(TBP)₃] and [UO₂(NO₃)₂(TBP)₂] and the other phase (II), in tetradecane. The inter-molecular interaction parameters and excess Gibbs energies (g ^E ) for the binary systems and TLS along the binodal curve were calculated from data on the mutual solubility in the binary system [Y(NO₃)₃(TBP)₃]-tetradecane and the ternary liquid system, using equations of the NRTL theory. For the binary system [Y(NO₃)₃(TBP)₃]-[UO₂(NO₃)₂(TBP)₂], g ^E < 0, and for the other binary systems, g ^E > 0. An algorithm is given for computer calculation of the binodal curve and nodes for the TLS within the framework of NRTL equations using the intermolecular interaction parameters.     

The solid solution and magnetic properties of (Mg,Cu)3 (PO4)2 phosphates

The powder synthesis of Mg_3−xCu_x(PO₄)₂ (0 ⩽ x ⩽ 3) between 1173 and 1273 K, shows a discontinuous solid solution. The X-ray diagrams of compositions 0 ⩽ x ⩽ 1.70 are similar to that of Mg₃(PO₄)₂. The compounds with 2.30 ⩽ x ⩽ 3 are isotypic with the stanskiite-related structure of Cu₃(PO₄)₂. Magnetic measurements (4.2–300K) achieved on powder samples with x = 0.50, 1.00, 1.50, 1.70 and 3 are reported. An antiferrodistorsive ordering induced by the cooperative Jahn — Teller effect of Cu²⁺ ions results in a one dimensional magnetic behaviour with the composition x = 3. The Bonner and Fisher's model for Heisenberg chains was used to determine the average value of the antiferromagnetic exchange.     

Optical properties of (1-x-y)B2O3-xLi2O-yMCI2 (M=Cd, Zn) glasses

Optical absorption and transmission spectra of (1-x-y)B₂O₃-xLi₂O-yMCI₂ (M=Cd, Zn) glasses of varying compositions were recorded in the UV-visible region. From the spectra, various optical parameters such as optical energy gap (E _opt), refractive index (n), optical dielectric constant (ɛ′), width of the tail of localized states in the forbidden gap (ΔE), ratio of carrier concentration to the effective mass (N/m*) and the constantB were evaluated. The effects of composition of glasses on these parameters are discussed.     

A2(MO4)3型化合物的晶体结构与热膨胀性质的研究

采用固相化学反应方法成功合成了GdY(WO4)3，Gd2(MoO4)3,DyGd(MoO4)3,DyTb(MoO4)3利用高、低温X射线衍射方法对其结构及其晶胞参数随温度的变化进行了研究。结果表明 GdY(WO4)3,Gd2(MoO4)3,DyGd(MoO4)3,DyTb(MoO4)3化合物的晶胞体积均随温度的升高而增大，为正热膨胀系数材料。通过对其晶体结构进行认真分析并与负热膨胀系数材料Sc2(WO4)3的结构进行对比，认为这四种化合物分别属于α—Gd2(MoO4）3型和CaWO4(白钨矿)型的结构相：其结构相对致密，氧原子不再只是两配位，不满足产生负热膨胀必要的结构条件，因此所合成的材料没有产生负热膨胀效应。     

Fabrication of Cd(3)As(2) nanowires by direct vapor-solid growth, and their infrared absorption properties

In this work the authors introduce and provide details of the synthesis and spectral characterization of single-crystal nanowires in less common, high performance, group II-V semiconductors such as Cd(3)As(2). The growth mechanism critically deviates from a known vapor-liquid-solid one by being completely non-catalytic and involving only two states: vapor and solid. The resultant nanowires range from ～50 to 200?nm in diameter and reach lengths up to tens of micrometers, with their fast growth direction being normal to the (112) crystal planes. According to infrared (IR) optical absorption measurements, the nanowires have several IR active direct type light absorption transitions at 0.11, 0.28 and 0.54 eV, suggestive of their possible utility in low cost optoelectronic devices and photodetectors operating in the long wavelength range of the electromagnetic spectrum.