KBr-RE(La,Sm)Br3-13%HBr-H2O四元体系25℃时的相平衡研究

Meyer在研究K。REBr。（RE一La,Sin）的结构及热力学性能时,引用文献的方法合成了2：1型化合物见s．其具体反应机理尚未明确表示．根据文觎',合成2：1型化合物CSZLUCI。分两步：第一步是LtJ;03与CSCI在氢氯酸介质中反应,生成2：1型含结晶水的中间体CS入llCI;·H20;第二步是中间体在HCI气氛下的高温脱水反应．反应如下：HC＊＊;HCI;＊ISOOC4CSCI＋l。LI,O。、ZCS,LSCI。·H,O、ZCS,LllCI。－H人）由上述反应过程可见,中间体的形成实际上应是LLICI。与CSCI在HCI介质中反应的生成物．那么,Meye…     

氟化钾负载改性法制备碱性NaY沸石

氟化钾（ＫＦ）可以高度分散于八面沸石表面，通过与ＮａＹ沸石表面发生相互作用产生ＫＯＨ类碱物种，使ＫＦ／ＮａＹ具有类似于ＫＯＨ／ＮａＹ的碱性，在异丙醇探针反应的碱性催化活性也与ＫＯＨ／ＮａＹ相似，由于沸石中的Ｓｉ组分容易与ＫＯＨ生成强度低的碱性化合物，妨碍ＫＦ或ＫＯＨ负载过程中强碱位的生成，因此ＫＦ／ＮａＹ的碱强度介于ＫＦ／ＳｉＯ２和ＫＦ／γ－Ａｌ２Ｏ３之间。     

Preparation and Crystal Structure of Potassium Iron Hydrogen Phosphate,KFe3(HPO4)2(H2PO4)6 · 4 H2O

Single crystals of potassium iron hydrogen phosphate, KFe₃(HPO₄)₂(H₂PO₄)₆ · 4 H₂O, were prepared hydrothermally by heating a mixture of Fe₂O₃, H₃PO₄ and K₂CO₃ with a small amount of water. It crystallizes monoclinic, space group C2/c (N° 15 Int. Tab.) with Z = 4 and a = 1701(2), b = 960.4(5), c = 1750(1) pm, β = 90.88(7)°. The crystal structure was solved by using 1716 unique reflections F₀ > 4σ(F₀) with a final wR2 value of 0.126 (SHELXL-93). The main feature of the crystal structure are layers formed by PO₄-tetrahedra around the FeO₆-octahedra parallel to (001). K⁺ and H₂O molecules connect these layers. Effective Coordination Numbers (ECoN), Mean Fictive Ionic Radii (MEFIR), Charge Distribution (CHARDI) and the Madelung Part of Lattice Energy (MAPLE) are calculated for the title compound. The existence of hydrogen bonds is confirmed by these calculations.     

纤维素基磁性聚偕氨肟树脂吸附Mn（Ⅶ）

用酸处理的纤维素基磁性聚偕氨肟树脂（AMAO）在溶液中吸附KMnO4，发生氧化还原反应的几率在2％以下；用碱处理的树脂（BMAO）作吸附剂，KMnO4还原为Mn（OH）4的比例剧增，达到或超过10％，并且与溶液的pH有关。但是，Mn（Ⅶ）被还原为Mn（Ⅳ）的量基本上不受KMnO4起始浓度、吸附剂添加量和吸附时间变化的影响。BMAO树脂吸附KMnO4的量是树脂偕氨肟基含量的5倍以上。超当量吸附现象反映了物理吸附的本质。     

氨-碘酸盐介质中白喉类毒素的平行催化氢波

在 0 .4mol/LNH3 NH4Cl (pH 8.3 1 )介质中 ,白喉类毒素 (DT)于 - 1 .89V(vs.SCE)处产生的极谱催化氢波可被碘酸钾进一步催化 ,峰电流明显增大 ,但峰电位不变 ,产生一种氢的新动力波 ,建议称其为平行催化氢波。在 0 .4mol/LNH3 NH4Cl(pH 8.3 1 ) - 5 .0× 1 0 - 3 mol/LKIO3介质中 ,DT平行催化氢波的二阶导数峰电流与其浓度在 0 .2 μg/mL～ 1 .0 μg/mL内呈线性关系 ,可用于生物制品中DT含量的测定。     

甲苯胺蓝指示反应动力学光度法测定痕量钌

在磷酸和热水浴中 ,钌 (Ⅲ )对高碘酸钾氧化甲苯胺蓝的反应具有催化作用 ,据此建立了测定钌的新催化光度法。钌在 0～ 0 .0 5 0 μg/ 2 5ml范围内与催化反应速率有良好的线性关系 ,检出限为 5 .5 3× 10 - 5μg·ml- 1。对 0 .0 30 μg/ 2 5ml钌 (Ⅲ )测定的相对标准偏差为 2 .0 % (n =11)。该催化反应对钌 (Ⅲ )和甲苯胺蓝分别为一级反应 ,其表观活化能为 5 0 .2 6kJ·mol- 1。试验了 4 0多种共存离子的影响 ,大多数的常见离子不干扰。该方法用于岩矿和冶金产品中钌的测定 ,相对标准偏差为 2 .1%～ 2 .4 % ,标准加入回收率为 10 0 .1%～ 10 5 .4 %。     

单扫描示波极谱法测定扑热息痛

扑热息痛与NaNO2在中性介质中发生反应，其亚硝化衍生物具有良好的电活性。在pH9．37的Britton-Robinson缓冲溶液中，于-0．56V(vs．SCE)产生灵敏的极谱还原峰，峰电流与扑热息痛质量浓度在0．007-0．4mg/L范围有良好的线性关系，检测下限为5μg/L。此法已用于测定小儿速效感冒灵。     

多巴酚丁胺的流动注射化学发光法测定

在盐酸介质中 ,高锰酸钾可氧化多巴酚丁胺产生化学发光 ,甲醛对该反应有较强的增敏作用 ,据此 ,建立了流动注射化学发光法测定多巴酚丁胺的方法 ;方法的线性范围为0.1～100mg·L -1,检出限为0.07mg·L -1 ,相对标准偏差为1.2 %(n=11,ρ=1.0mg·L -1) ;该法用于药物中多巴酚丁胺含量的测定 ,结果令人满意。     

Darstellung,Charakterisierung und Reaktionsverhalten von Natrium‐ und Kaliumhydridosilylamiden R2(H)Si—N(M)R′ (M = Na,K) — Kristallstruktur von [(Me3C)2(H)Si—N(K)SiMe3]2·THF

Preparation, Characterization and Reaction Behaviour of Sodium and Potassium Hydridosilylamides R₂(H)Si—N(M)R′ (M = Na, K) — Crystal Structure of [(Me₃C)₂(H)Si—N(K)SiMe₃]₂ · THF The alkali metal hydridosilylamides R₂(H)Si—N(M)R′ 1a‐Na — 1d—Na and 1a‐K — 1d‐K ( a : R = Me, R′ = CMe₃; b : R = Me, R′ = SiMe₃; c : R = Me, R′ = Si(H)Me₂; d : R = CMe₃, R′= SiMe₃) have been prepared by reaction of the corresponding hydridosilylamines 1a — 1d with alkali metal M (M = Na, K) in presence of styrene or with alkali metal hydrides MH (M = Na, K). With NaNH₂ in toluene Me₂(H)Si—NHCMe₃ ( 1a ) reacted not under metalation but under nucleophilic substitution of the H(Si) atom to give Me₂(NaNH)Si—NHCMe₃ ( 5 ). In the reaction of Me₂(H)Si—NHSiMe₃ ( 1b ) with NaNH₂ intoluene a mixture of Me₂(NaNH)Si—NHSiMe₃ and Me₂(H)Si—N(Na)SiMe₃ ( 1b‐Na ) was obtained. The hydridosilylamides have been characterized spectroscopically. The spectroscopic data of these amides and of the corresponding lithium derivatives are discussed. The ²⁹Si‐NMR‐chemical shifts and the ²⁹Si—¹H coupling constants of homologous alkali metal hydridosilylamides R₂(H)Si—N(M)R′ (M = Li, Na, K) are depending on the alkali metal. With increasing of the ionic character of the M—N bond M = K > Na > Li the ²⁹Si‐NMR‐signals are shifted upfield and the ²⁹Si—¹H coupling constants except for compounds (Me₃C)(H)Si—N(M)SiMe₃ are decreased. The reaction behaviour of the amides 1a‐Na — 1c‐Na and 1a‐K — 1c‐K was investigated toward chlorotrimethylsilane in tetrahydrofuran (THF) and in n‐pentane. In THF the amides produced just like the analogous lithium amides the corresponding N‐silylation products Me₂(H)Si—N(SiMe₃)R′ ( 2a — 2c ) in high yields. The reaction of the sodium amides with chlorotrimethylsilane in nonpolar solvent n‐pentane produced from 1a‐Na the cyclodisilazane [Me₂Si—NCMe₃]₂ ( 8a ), from 1b‐Na and 1‐Na mixtures of cyclodisilazane [Me₂Si—NR′]₂ ( 8b , 8c ) and N‐silylation product 2b , 2c . In contrast to 1b‐Na and 1c‐Na and to the analogous lithium amides the reaction of 1b‐K and 1c‐K with chlorotrimethylsilane afforded the N‐silylation products Me₂(H)Si—N(SiMe₃)R′ ( 2b , 2c ) in high yields. The amide [(Me₃C)₂(H)Si—N(K)SiMe₃]₂·THF ( 9 ) crystallizes in the space group C2/c with Z = 4. The central part of the molecule is a planar four‐membered K₂N₂ ring. One potassium atom is coordinated by two nitrogen atoms and the other one by two nitrogen atoms and one oxygen atom. Furthermore K···H(Si) and K···CH₃ contacts exist in 9 . The K—N distances in the K₂N₂ ring differ marginally.     

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.