Six- and five-coordinated complexes of Co(II) with 2-(2′-pyridyl)quinoxaline. Crystal structures of the complexes [CoLCl2(DMF)] and [CoL2(H2O)2](ClO4)2·H2O·2CH3OH

Reaction of Co(II) perchlorate hexahydrate and anhydrous Co(II) chloride with the ligand 2-(2′-pyridyl)quinoxaline (L) leads to the formation of the novel five- and six-coordinated complexes CoLCl₂(DMF) (1) and [CoL₂(H₂O)₂](ClO₄)₂·H₂O·2CH₃OH (2), correspondingly. The crystal structures of the above complexes show a trigonal bipyramidal geometry around the metal atom for complex 1 and a distorted octahedral geometry for complex 2.     

Synthesis,structure, and characterization of polymeric lanthanide 2-aminoterephthalate frameworks [Ln2(atp)3(H2O)2]·dmf·4H2O

X-ray crystallography reveals four isostructural lanthanide polymeric solids, [Ln₂(atp)₃(H₂O)₂]·dmf·4H₂O (atp = 2-aminoterephthalate; dmf = N,N′-dimethylformamide; Ln = La (1), Ce (2), Pr (3) and Nd (4), respectively) that are obtained from the solvothermal synthesis which are crystallized in an interesting 3D polymeric framework with a (4,4,6)-linked {4²·8⁴}{4⁴·6²}₂{4⁸·6⁶·8}₂ fsy net topology. Upon excitation at 350 nm, they all show the solid state ligand-centered luminescences but both 2 and 3 also exhibit the weak lanthanide-based characteristic emissions in the visible region at room temperature. The cyclic voltammetric investigation indicates that 2 exhibits appreciable electrochemical activity for formaldehyde.     

Crystal Structure and Physicochemical Properties of Two Supramolecular Compounds: (C4H8NH2)4[Mo8O26] and (NH4)Na2[AsIIIMo6O21(O2CCH2NH3)3]·8H2O

Two inorganic–organic hybrid supramolecular compounds based on polyoxometalates formulated as (C₄H₈NH₂)₄[Mo₈O₂₆] (1) and (NH₄)Na₂[As^IIIMo₆O₂₁(O₂CCH₂NH₃)₃]·8H₂O (2) have been synthesized by conventional solution method and characterized by infrared, UV–Vis and single-crystal X-ray diffraction analyses. Thermal analysis was performed to study their thermal stability. The atomic arrangement in compound (1) can be described as inorganic layers built by [Mo₈O₂₆]^4?, pyrrolidinium cations are embedded into layers. The fascinating structural feature of compound (2) is that the glycine molecules are bounded to two edge-sharing Mo centers via their carboxylate functionality leading to functionalized heteropolymolybdate [As^IIIMo₆O₂₁(O₂CCH₂NH₃)₃]^3?, extensive net hydrogen bonds between cations and anions contribute to the crystal packing. The electrochemical behavior of compound (2) has been studied.     

Microparticles of α-Bi2O3 Obtained from Bismuth Basic Nitrate [Bi6O6(OH)2(NO3)4·2H2O] with Photocatalytic Properties

Topics in Catalysis - Alpha phase bismuth oxide (α-Bi2O3) microparticles were prepared through the annealing at 600 °C of basic bismuth nitrate [Bi6O6(OH)2(NO3)4·2H2O]...     

Pb4[Ce(Ⅳ)W10O33]·32H2O纳米粒子的制备

以Triton X-100/n-C10H21OH/H2O体系W/O微乳液为基础,分别以K8[Ce(Ⅳ)W10O33]·32H2O 和Pb(NO3)2水溶液代替组分水制备W/O微乳液.然后将两种微乳液混合,得到黄色沉淀的Pb4[Ce(Ⅳ)W10O33]·32H2O纳米粒子,同时有少量纳米管生成.经电镜分析所得Pb4[Ce(Ⅳ)W10O33]·32H2O纳米粒子为粒径低于5 nm的圆球状颗粒,所得Pb4[Ce(Ⅳ)W10O33]·32H2O纳米管管长约为50 nm,管径约为5 nm.并用TG-DTA和Raman对该化合物进行了表征.     

A highly nuclear vanadium-containing tungstobismutate: synthesis and crystal structure of K11H[(BiW9O33)3Bi6(OH)3(H2O)3V4O10]·25 H2O

A novel and large heteropolyanion [(BiW₉O₃₃)₃Bi₆(OH)₃(H₂O)₃V₄O₁₀]¹²⁻ has been synthesized by reaction of sodium metavanadate with Na₉[BiW₉O₃₃]·16H₂O in acetate buffer solutions (at pH 4.8). The present anion has a trilobal structure in which three α-B {BiW₉O₃₃} units are connected to each other by an unique core [Bi₆(OH)₃(H₂O)₃V₄O₁₀]¹⁵⁺. A central bismutate/vanadate-mixed core comprises three sets of two types of the BiO₆ pentagonal pyramid, the edge-sharing VO₅ square-pyramidal triad, and a VO₄ tetrahedron.     

氢氧化钡[Ba(OH)_2·8H_2O]

正1)性质。氢氧化钡易形成结晶水合物,其中Ba(OH)2·8H2O最常见。Ba(OH)2·8H2O是白色粉末或单斜晶系晶体,加热至77.9℃溶于自身结晶水。溶于水,水溶液呈碱性。还溶于稀酸和甲醇。难溶于乙醇、丙酮。在空气中吸收二氧化碳变成碳酸钡。加热到约800℃失去结晶水而生成氧化钡。有毒。2)用途。用于制造钡盐、有机钡化合物、钡基润滑脂。用于精制动植物油类、蔗糖、甜菜。用作塑料稳定剂、造纸添加剂、密     

Synthesis of tributyl citrate catalyzed by Ce(SO4)2·4H2O/ NH2SO3H

研究了柠檬酸与正丁醇在Ce(SO₄)₂·4H₂O/ NH₂SO₃H复配催化剂催化作用下制备柠檬酸三丁酯的工艺条件。实验结果表明Ce(SO₄)₂·4H₂O/ NH₂SO₃H催化合成柠檬酸三丁酯的最佳反应条件为：醇酸摩尔比为4.0∶1,催化剂用量为1.5%（以柠檬酸质量计）,m[Ce(SO₄)₂·4H₂O]∶m(NH₂SO₃H)=2∶1,反应温度为150 ℃,反应时间为7 h,酯化率＞98.5%,精制后产品纯度>99.5%。     

Synthesis,structure and characterization of (NH4)2[Cu2(H2O)4(NH3CH2COO)2(NH2CH2COO)2]H2V10O28·6H2O

The decavanadate with a novel glycine–glycinato complex of copper (II) in the cationic part, (NH₄)₂[Cu₂(H₂O)₄(NH₃CH₂COO)₂(NH₂CH₂COO)₂]H₂V₁₀O₂₈·6H₂O (1), has been prepared and characterized by elemental analysis, infrared and EPR spectroscopies. The triplet X band EPR spectrum of powdered sample evidenced magnetic interaction between the Cu(II) atoms in the dimeric unit which is probably realized through the bridging water molecules in this part of the complex. A single crystal X-ray diffraction study revealed that the structure of 1 contains cationic copper complex with a rare Cu(H₂O)₂Cu double bridge. In this cation, a simultaneous bidentate N, O– and monodentate O– coordination of glycine to the same central atom was observed for the first time.     

Synthesis,structure, and properties of two novel copper(II) complexes, [Cu(phen)(L)2]·6H2O and [Cu(phen)3]·(ClO4)2

Two novel copper(II) complexes, namely [Cu(phen)(L)₂]·6H₂O (1) and [Cu(phen)₃]·(ClO₄)₂ (2) have been synthesized under mild condition (HL = 5-methyl-1H-pyrazole-3-carboxylic acid, phen = 1,10-phenanthroline). We report the structural evidence of discrete water decamer conformation in the solid state. These units are found to act as supramolecular glue in the aggregation of mononuclear copper(II) complex to give a three-dimensional network through hydrogen-bonding. The preliminary investigation on the thermal behavior and the anion exchange property of the complexes are presented.     

Surface immobilisation of the sandwich type Na14[Fe4(Ox)4(H2O)2(SbW9O33)2]·60H2O polyoxometalate

A functionalised Fe-substituted Keggin Na₁₄[Fe₄(C₂O₄)₄(H₂O)₂(SbW₉O₃₃)₂]·60H₂O type POM termed “Fe₄Ox₄” has been successfully immobilised onto carbon electrode surfaces through the employment of conducting polypyrrole films and the layer-by-layer (LBL) technique. For the POM doped polypyrrole films the redox systems associated with the POM's tungsten-oxo framework was not apparent upon redox cycling, however a reversible redox couple associated with the Fe^III/II redox system was clearly seen within the pH range 2–7. Organised multilayer assemblies were constructed by the employment of the layer by layer (LBL) technique through alternating anionic Fe₄Ox₄ layers and cationic Ru^II metallodendrimers with poly(diallyldimethylammonium chloride) (PDDA) employed as an initial base layer. Stable redox couples associated with both the Fe^III/II and tungsten-oxo framework, for the Fe₄Ox₄ POM, and the Ru^III/II for the metallodendrimer, were clearly observed upon layer construction and redox switching within the pH domain of 2–7. The resulting multilayer assembly showed good stability towards redox cycling. Further investigations into the multilayer assembly were undertaken by determining it is charge transfer resistance using AC-impedance voltammetry. The layer also showed catalytic ability towards the reduction of H₂O₂ at pH 6.5.     

混合配体配合物[Co3(BTC)2(Lb)2(CH3CH2OH)2·4H2O]n的合成与晶体结构

以1,3,5-均苯三甲酸(H_3BTC)、2-[1-(2-吡嗪基)乙缩醛腙(L_a)、醋酸钴、为原料采用水热法合成了配合物[Co_3(BTC)_2(L_b)_2(CH_3CH_2OH)_2·4H_2O]_n(1)(L_b=2-乙酰基吡嗪缩水合肼)。配合物晶体属单斜晶系,空间群C2/c。X-射线单晶衍射结果表明:两个Co~(2+)离子与氧原子、氮原子配位,均为变形八面体构型。席夫碱配体在配位过程中分解为2-乙酰基吡嗪缩水合肼,BTC~(3-)配体全部去质子化且以μ_4-的配位模式将两个Co~(2+)连接成6-连接的三维结构。晶胞参数:a=15.146(9)?,b=13.417(8)?,c=23.564(18)?,β=90.087(8)°,V=4789(5)?~3,Z=4。     

Variation of [AgCN]∞ chain configuration in silver(I) double salts: crystal structures of AgCN·2AgNO3 and AgCN·2AgClO4·2H2O

AgCN·2AgNO₃ (1) contains a linear [AgCN]_∞ chain that essentially retains the characteristics of neat silver cyanide, with two Ag–ONO₂ fragments weakly bound to each head-turned-tail disordered cyanide group (Ag2–C1=2.598(4) Å). In AgCN·2AgClO₄·2H₂O (2), the [AgCN]_∞ chain takes a zigzag configuration with Ag(H₂O) fragments attached to both sides, resulting in a μ₄-η¹κC:η¹κN coordination mode for each ordered cyanide ion. The zigzag chains are cross-linked by O–H⋯O hydrogen bonds to form a close-packing of elongated hexagonal channels, with ordered perchlorate anions accommodated in double columns inside each channel.