Lamellare Schichten auf der Grundlage von Wasserstoffbrücken und π‐Stapelung: Kristallstrukturen der Komplexe [Mg(H2O)6]Z2 und [Be(H2O)4]Z2�2 H2O mit Z‐ = C6H4(SO2)2N‐: Metallsalze des Benzol‐1, 2‐di(sulfonyl)amins. 8 [1, 2]

Metal Salts of Benzene‐1, 2‐di(sulfonyl)amine. 8. Lamellar Layers Based upon Hydrogen Bonding and π‐Stacking: Crystal Structures of the Complexes [Mg(H₂O)₆]Z₂ and [Be(H₂O)₄]Z₂�2 H₂O, where Z^‐ is C₆H₄(SO₂)₂N^‐ The crystal structures of the title complexes (both triclinic, space group P1¯, Z = 1 for M = Mg, Z = 2 for M = Be) have been determined by low‐temperature X‐ray diffraction. They consist of non‐coordinating ortho‐benzenedisulfonimide anions and, respectively, inversion‐symmetric octahedral [Mg(H₂O)₆]²⁺ cations or tetrahedral [Be(H₂O)₄]²⁺ cations and two non‐coordinating water molecules. In both structures, all O—H hydrogen bond donor groups are used to associate the components into two‐dimensional assemblies comprising an internal polar lamella of metal cations, (SO₂)₂N groups and water molecules, and hydrophobic peripheral regions consisting of vertically protruding benzo rings. Carbocycles drawn alternatingly from adjacent layers form π‐stacking arrays, whereby the aromatic rings display intercentroid distances in the range 340—370 pm. Several short C—H ⃜O contacts, which may be viewed as weak hydrogen bonds, occur within and between the layers.     

Polysulfonylamine. CLII [1] Kristallstrukturen von Metall‐di(methansulfonyl)amiden. 6 [2] Drei Schichtstrukturen: Die isotypen binären Verbindungen M[(MeSO2)2N]2 (M = Sr,Pb) und das Ethanol‐Solvat Pb[(MeSO2)2N]2 · EtOH

Polysulfonylamines. CLII. Crystal Structures of Metal Di(methanesulfonyl) amides. 6. Three Layer Structures: The Isotypic Binary Compounds M[(MeSO₂)₂N]₂ (M = Sr, Pb) and the Ethanol Solvate Pb[(MeSO₂)₂N]₂ · EtOH Low‐temperature X‐ray crystal structures are reported for the layer compounds SrA₂ (monoclinic, space group P2₁/n, Z′ = 1), PbA₂ (isotypic and isostructural with SrA₂), and PbA₂·EtOH (triclinic, P1¯, Z′ = 1), where A^— denotes the anion obtained by deprotonation of the strong NH acid (MeSO₂)₂NH. The ternary compound appears to be the first crystallographically established ethanol solvate of a lead(II) complex. In the two‐dimensional coordination networks, the cations adopt either a distorted cubic or, in the solvate, an irregular (O₆N₂)‐octacoordination, the metal centres of the isotypic structures forming close contacts to two (O, N)‐chelating and four κ¹O‐bonding anions, whereas in the solvate one of the latter ligands is displaced by an EtOH molecule. In the isotypic structures, the Pb—O distances are systematically longer than the Sr—O distances and the Pb—N bonds shorter than the Sr—N bonds, which correlates with the softer character of Pb²⁺ as compared to Sr²⁺. The 6s lone pair on Pb²⁺ is stereochemically inactive in both lead compounds. Analogies and discrepancies between the layer architectures are discussed in detail, including an evaluation of short C—H···O contacts in terms of weak hydrogen bonding. Two complexes of composition PbA₂·2 L, where L is pyridine or 1, 10‐phenanthroline, have been synthesized and characterized by analytical methods.     

岩石矿物中铀钍的分析方法进展—湿法化学法

从化学分析(破坏性分析)和非破坏性分析两个方面入手系统地介绍了岩石矿物中铀钍的分析方法。湿法化学法部分着重介绍了岩石矿物中铀钍的化学分析方法原理、特点和应用范围。常用的化学分析包括重量法、比色法、容量法、光度法、激光荧光法、极谱法、光谱法、α能谱法和先进的质谱法等;随着新仪器手段的发展进步,先进的化学分析手段特别是电感耦合等离子质谱法(ICP-MS)如雨后春笋般普及推广,其它传统湿法化学分析应用越来越少。     

引黄工程大型地下泵站围岩监测技术研究

山西省引黄工程国际一标主要包括2只大型地下泵站及引水洞,通过对具备不同特征的泵房、洞室、立井等结构部位的围岩及内衬结构应力、应变、位移等监测与分析,及时总结围岩变形规律以指导施工,控制围岩动态,掌握围岩断面尺寸的变化,了解围岩的松弛程度及影响范围,确保施工期和运行期的安全,为其他类似大型地下复杂结构围岩及内衬结构的安全性及耐久性研究提供可靠的技术支持。     

Silber(I)‐di(arensulfonyl)amide und ein Silber(I)‐(arensulfonyl)(alkansulfonyl)amid: Von Bändern zu lamellaren Schichten mit kurzen Zwischenschichtkontakten C–H…Hal–C oder C–Br…Br–C

Structures of Ionic Di(arenesulfonyl)amides. 2. Silver(I) Di(arenesulfonyl)amides and a Silver(I) (Arenesulfonyl)(alkanesulfonyl)amide: From Ribbons to Lamellar Layers Exhibiting Short C–H…Hal–C or C–Br…Br–C Interlayer Contacts Low‐temperature X‐ray crystal structures are reported for AgN(SO₂C₆H₄‐4‐X)₂ · H₂O, where X is Cl ( 4 ) or Br ( 5 ), and for AgN(SO₂Ph)(SO₂Me) ( 6 ). Compounds 4 and 5 and the previously described F analogue ( 3 ) are isotypic, though not strictly isostructural (monoclinic, space group P2₁/c, Z = 4, but egregiously large discrepancies of x and z coordinates for corresponding atoms). Throughout this triad, glide‐plane related formula units are linked along the z axis to form infinite ribbons [(ArSO₂)₂N–Ag(μ‐H₂O)]_∞, in which Ag extends its coordination number to five by accepting one Ag–O bond from each of the (ArSO₂)₂N^⊖ ligands in the adjacent units. By means of O–H…O(S) hydrogen bonds, the ribbons are associated into lamellar layers parallel to the xz plane. Owing to the folded conformation of the anions, the layers display an inner polar region of Ag atoms, H₂O molecules and N(SO₂)₂ groups, outer apolar regions of stacked pairs of aryl rings, and interlayer regions hosting the halogen atoms. Inspection of the latter areas provides sound evidence that the distinct juxtapositions of adjacent layers arise from specific interlamellar attractions and repulsions ( 3 : two C–H…F, all F…F beyond the van der Waals limit d_W; 4 : one C–H…Cl, close packing of Cl atoms at Cl…Cl ≈ d_W; 5 : one C–H…Br, one short Br…Br contact < d_W, all other Br…Br > d_W). Structure 6 (monoclinic, P2₁/n, Z = 4) consists of a lamellar coordination polymer, in which the cation accepts one Ag–N and three Ag–O bonds drawn from four different anions. On account of crystal symmetry, the extended ligand has its Ph and Me groups distributed on both sides of the sheet, the phenyl rings forming the apolar regions of the lamella, whereas the smaller methyl groups are integrated into the corrugated inorganic region by means of weak C–H…O hydrogen bonds.     

An Unexpected Layered Structure in Inorganic Cyanide Clusters: [Cu4(μ3-OH)4][Re4(μ3-Te)4(CN)12]

Diffusion of aqueous solutions of K₄[Re₄Te₄(CN)₁₂] and CuCl₂ in the opposite direction through silica gel gives rise to the new polymer-like compound 1 . This complex has a layered structure built from the interconnected cubane-like cluster cations [Cu₄(μ₃-OH)₄]⁴⁺ and the cluster anions [Re₄Te₄(CN)₁₂]⁴⁻ (see picture).     

诺氟沙星插层镁铝水滑石新型药物-无机复合材料的超分子结构、热稳定性和缓释性能

采用共沉淀和离子交换方法将抗生素类药物诺氟沙星(Nor)插入到Mg-Al-LDHs层间, 制备了一种新型的药物-无机复合材料. 借助XRD, FTIR, UV-Vis, TG-DTA和ICP等手段对样品进行了表征. 结果表明, Nor-阴离子可取代层间的NO3-, 组装得到晶体结构良好的Nor-LDHs. XRD表征得到Nor-LDHs的层间距为1.29~1.33 nm, 并与根据PM3半经验分子轨道法优化计算得到的Nor-三维尺寸进行比较, 推测客体Nor-是沿短轴方向以单层垂直交替的方式排布于层间, 与主体层板通过氢键与静电作用形成超分子结构; 该超分子结构诺氟沙星-水滑石复合材料与诺氟沙星相比, 其热稳定性、耐酸性及缓释性能均有大幅度提高, 缓释实验数据符合Bhaskar方程和一级动力学方程模型.     

Second-harmonic generation of two-dimensional elastic wave propagation in an infinite layered structure with nonlinear spring-type interfaces

The two-dimensional elastic wave propagation in an infinite layered structure with nonlinear interlayer interfaces is analyzed theoretically to investigate the second-harmonic generation due to interfacial nonlinearity. The structure consists of identical isotropic linear elastic layers that are bonded to each other by spring-type interfaces possessing identical linear normal and shear stiffnesses but different quadratic nonlinearity parameters. Explicit analytical expressions are derived for the second-harmonic amplitudes when a single monochromatic Bloch mode propagates in the structure in arbitrary directions by applying the transfer-matrix approach and the Bloch theorem to the governing equations linearized by a perturbation method. The second-harmonic generation by a single nonlinear interface and by multiple consecutive nonlinear interfaces are shown to be profoundly influenced by the band structure of the layered structure, the fundamental Bloch wave mode, and its propagation direction. In particular, the second harmonics generated at multiple consecutive interfaces are found to grow cumulatively with the propagation distance when the phase matching occurs between the Bloch modes at the fundamental and double frequencies.     

Dispersion characteristics of wave propagation in layered piezoelectric structures: Exact and simplified models

This article presents a study of the dispersion characteristics of wave propagation in layered piezoelectric structures under plane strain and open-loop conditions. The exact dispersion relation is first determined based on an electro-elastodynamic analysis. The dispersion equation is complicated and can be solved only by numerical methods. Since the piezoelectric layer is very thin and can be modeled as an electro-elastic film, a simplified model of the piezoelectric layer reduces this complex problem to a non-trivial solution of a series of quadratic equations of wave numbers. The model is simple, yet captures the main phenomena of wave propagation. This model determines the dispersion curves of PZT4-Aluminum layered structures and identifies the two lowest modes of waves: the generalized longitudinal mode and the generalized Rayleigh mode. The model is validated by comparing with exact solutions, indicating that the results are accurate when the thickness of the layer is smaller or comparable to the typical wavelength. The effect of the piezoelectricity is examined, showing a significant influence on the generalized longitudinal wave but a very limited effect on the generalized Rayleigh wave. Typical examples are provided to illustrate the wave modes and the effects of layer thickness in the simplified model and the effects of the material combinations.     

Synthesis of spherical Y2O3:Er emitting particles with variable radial composition by controlled double-jet precipitation of layered precursors

Spherical (Y_0.98Er_0.02)₂(OH)₅(NO₃)·xH₂O particles were synthesized by controlled double-jet precipitation, with a “core” of pure layered yttrium hydroxide nitrate, and a “shell” of co-precipitated yttrium-erbium layered hydroxide nitrates. With an increase in precipitation pH from 7 to 9.5, the size of layered “building units” decreases and the architecture of their assemblies changes from flower-like through network-like spherical to irregular agglomerates. From there, spherical particles gradually increase their diameter due to the continuous uniform growth of curved layered sheets on their surface. It was established that such growth behavior and network-like architecture of spherical particles was retained even when yttrium was replaced by erbium ions in the layered host lattice during the formation of an Er-enriched “shell”. Analysis of SEM, EDS, XPS, photoluminescence spectra and concentration quenching effects of heat-treated Y₂O₃:Er (2 at.%) particles indicate that the radial distribution of erbium in particles is most controllable in a narrow pH range of co-precipitation of layered precursors (pH 8). Вy widely varying the elemental composition of “building units” during co-precipitation, one can simultaneously finely control the composition of layered hydroxides in the radial direction of the spherical particles and grow multicomponent “multi-shell” powders with desired properties.