Polysulfonylamine. CLX [1] Kristallstrukturen von Metall‐di(methansulfonyl)amiden. 10 [2] Die dreidimensionalen Koordinationspolymere M[(CH3SO2)2N] mit M = Kalium,Rubidium, Caesium (isotype Strukturen für M = K,Rb)

Polysulfonylamines. CLX. Crystal Structures of Metal Di(methanesulfonyl)amides. 10. The Three‐Dimensional Coordination Polymers M[(CH₃SO₂)₂N], where M is Potassium, Rubidium, Cesium (Isotypic Structures for M = K, Rb) Low‐temperature X‐ray crystal structures are reported for KA (monoclinic, space group P2₁/c, Z′ = 1), RbA (isotypic and isostructural with KA), and CsA (monoclinic, P2₁/n, Z′ = 1), where A^— denotes the anion obtained by deprotonation of the strong nitrogen acid (MeSO₂)₂NH. In KA and RbA, the anion is distorted into a rare C₁ conformation, whereas the standard C₂ conformation is retained in the cesium complex. The structures consist of three‐dimensional coordination networks, in which each cation adopts an irregular (O₆N)‐heptacoordination by forming close contacts to one (O, N)‐chelating, one (O, O)‐chelating and three κ¹O‐bonding ligands; however, the coordination number for Cs⁺ is effectively increased to 8 by a very short Cs···Cs contact distance of 422.5 pm. The crystal packings of the isotypic compounds KA and RbA display lamellar layer substructures that involve six independent ligand‐metal bonds and comprise an internal cation lamella and peripheral regions built up from anion monolayers; the 3D framework is completed by one independent M—O bond cross‐linking the layer substructures. In contrast, CsA features anion monolayers that intercalate planar zigzag chains of cations (Cs···Cs alternatingly 422.5 and 487.5 pm, Cs···Cs···Cs 135.7°), whereby each chain is surrounded and coordinated by four anion stacks and each anion stack connects two cation chains. All structures exhibit close C—H···A interanion contacts consistent with weak hydrogen bonding.     

Convenient procedure of Horner-Wadsworth-Emmons olefination for the synthesis of simple and functionalized α,β-unsaturated nitriles

A mild and practical procedure of Horner-Wadsworth-Emmons olefination promoted by lithium hydroxide and α-cyano phosphonates has been set up for the synthesis of α,β-unsaturated nitriles. The reaction conditions are tolerated by functionalized ketones and the exclusive formation of E-γ-hydroxy α,β-unsaturated nitriles has been observed.     

超声波处理对球形β-Ni(OH)2结构及电化学性能的影响

A method of ultrasonic treatment （UST） was first used to modify the structure and electrochemical performance of nickel hydroxide for the active material of nickel series alkaline batteries. The experimental results showed that UST was an effective method to improve the electrochemical performance of β-Ni（OH）2 such as specific discharge capacity, discharge potential, electrochemical reversibility and oxygen evolution over-potential. The results of electrochemical impedance spectroscopy, powder X-ray diffraction and particle size distribution indicated that the improvement of the performance of β-Ni（OH）2 through UST was attributed to the reduction of the charge-transfer resistance （Rt） and the diffusion impedance （Zw）, which resulted from the decrease of the crystallite and particle size and the increase of interlayer spacing. Diffusion coefficient of proton DH of ultrasonic treated β-Ni（OH）2 gained by CV tests was 1.13 × 10^-11 cm^2/s, and the average discharge specific capacity of ultrasonic treated β-Ni（OH）2 electrode was 301 mAh/g.     

Synthesis, nuclear, and magnetic structures and magnetic properties of [Mn3(OH)2(SO4)2(H2O)2

[Mn(3)(OH)(2)(SO(4))(2)(H(2)O)(2)] and its deuterated analogue were synthesized by a hydrothermal technique and characterized by differential thermal analysis, thermogravimetric analysis, and IR spectroscopy. Its nuclear structure, determined by single-crystal X-ray analysis and Rietveld analysis of neutron powder-diffraction data, consists of a 3D network of chains of edge-sharing Mn(1)O(6), running along the c axis, connected by the apices of Mn(2)O(6) and SO(4) units. It is isostructural to the nickel analogue. Determination of the magnetic structure and measurements of magnetization and heat capacity indicate the coexistence of both magnetic long-range ordering (LRO) and short-range ordering (SRO) below a Néel temperature of 26 K, while the SRO is retained at higher temperatures. The moments of the two independent Mn atoms lie in the bc plane, and that of Mn(1) rotates continuously by 54 degrees towards the c axis on decreasing the temperature from 25 to 1.4 K. While the SRO may be associated with frustration of the moments within a Mn(3) trimer, the LRO is achieved by antiparallel alignment of the four symmetry-related trimers within the magnetic unit cell. A spin-flop field, measured by dc and ac magnetization on a SQUID, is observed at 15 kOe.     

Zwei neue Metatitanate mit fünffach koordiniertem Titan: CsNaTiO3 und RbNaTiO3

Two New Metatitanates with Five-coordinated Titanium: CsNaTiO₃ and RbNaTiO₃ [1] The new oxides CsNaTiO₃ (I) and RbNaTiO₃ (II) are obtained by heating well grounded mixtures of the binary oxides in Ni-tubes as colourless platelike crystals. I: CsO_0.56, NaO_0.48 and TiO₂, Cs:Na:Ti = 1.1:1.1:1.0; 600°C, 61 d as well as CsO_0.97, NaO_0.48 and Ti₂O₃, Cs:Na:Ti = 1.5:3.0:1.0; 760°C, 27 d. II: RbO_0.52, NaO_0.48 and TiO₂, Rb:Na:Ti = 1.1:1.1:1.0; 750°C, 14 d as well as RbO_0.98, NaO_0.48 and Ti₂O₃, Rb:Na:Ti = 1.5:3.1:1.0; 760°C, 27 d. CsNaTiO₃ (orthorhombic, Cmcm) is nearly isostructural with KNaTiO₃ [2]; a = 601.4(1) pm, b = 1 120.3(1) pm, c = 563.4(1) pm (Guinier-Simon-Data, Z = 4). RbNaTiO₃ (monoclinic, C2/c) is isostructural with KNaTiO₃; a = 590.3(1) pm, b = 1 098.4(1) pm, c = 555.1(0) pm, β = 92.15° (Guinier-Simon-Data, Z = 4). Both structures are determined by using four-circle diffractometer data (CsNaTiO₃: Siemens AED2, 2 896I_o(hkl), MoKα , R = 2.4%, R_w = 2.3%; RbNaTiO₃: Philips PW 1 100, 2 743I_o(hkl), AgKα , R = 9.9%, R_w = 8.9%; additional data see text). The Madelung Part of Lattice Energy (MAPLE), Effective Coordination Numbers (ECoN), Mean Fictive Ionic Radii (MEFIR) and the Charge Distribution in Solids are calculated and discussed.     

Coprecipitation with metal hydroxides for the determination of beryllium in seawater by graphite furnace atomic absorption spectrometry

Coprecipitation first with magnesium hydroxide, next with tin(IV) hydroxide is developed for the determination of traces of beryllium in sea-water. To a 200-ml sample is added a sodium hydroxide solution to form magnesium hydroxide at pH 11.5, on which beryllium is quantitatively coprecipitated. The precipitate is separated by centrifugation and dissolved in 2 ml of 12 mol/l hydrochloric acid. The resulting solution (ca. 10 ml) is mixed with 2 mg of tin (IV) carrier and the pH is adjusted to 5.0 to collect the beryllium on tin (IV) hydroxide, leaving magnesium ions in the solution. The tin (IV) hydroxide is centrifuged, dissolved in 0.1 ml of 5 mol/l hydrobromic acid, and then diluted to 1 ml with water. Magnesium is so added as to be 500 g/ml for increasing the sensitivity about four times, and the beryllium in the solution is determined by graphite furnace atomic absorption spectrometry. The experiments with synthetic seawater samples showed that pg — g amounts of beryllium can be coprecipitated on the metal hydroxides and beryllium at the low ng/1 level can be determined with reasonable precision (RSD < 10%). The detection limit of the proposed method is 0.5 ng/l of beryllium in seawater.     

Studies on Colloidal Properties of Mixed Metal Hydroxide－Clay Aqueous Suspension

ＳｔｕｄｉｅｓｏｎＣｏｌｌｏｉｄａｌＰｒｏｐｅｒｔｉｅｓｏｆＭｉｘｅｄＭｅｔａｌＨｙｄｒｏｘｉｄｅ－ＣｌａｙＡｑｕｅｏｕｓＳｕｓｐｅｎｓｉｏｎＮＯＵｗａｎ－ｇｕｏ；ＺＨＡＮＧＣｈｕｎ－ｇｕａｎｇ；ＳＵＮＤｅ－ｊｕｎ；ＨＡＮＳｈｕ－ｈｕａａｎｄＷＡＮＧ...     

Synthesis and Characterization of PE-g-MA/MgAl-LDH Exfoliation Nanocomposite via Solution Intercalation

Anorgano modifiedMgAl layereddoublehydroxide (OMgAl LDH )wassuccessfullyexfoliatedinthexylenesolutionofpolyethylene grafted maleicanhydride (PE g MA )underre fluxingcondition .APE g MA/MgAl LDHexfoliationnano compositewasformedaftertheprecipitationofPE g MAfromthedispersionsystem .ThestructureandthermalpropertyofthePE g MA/MgAl LDHexfoliationnanocompositewerechar acterizedbyX raydiffraction (XRD ) ,transmissionelectronmicroscopy (TEM ) ,andthermogravimetryanalysis (TGA ) .The…     

Intercalation assembly of kojic acid into Zn-Ti layered double hydroxide with antibacterial and whitening performances

The inhibitor of melanin and the bacteriostatic agent kojic acid was inserted into Zn-Ti layered double hydroxide (LDH) by anion-exchange reaction. The structure, slow release, antibacterial and skin whitening activity were studied.