Studies of the electrodeposition of palladium from baths based on [Pd(NH3)2X2] salts. I. [Pd(NH3)2Cl2] baths

Spectroscopic techniques are used to confirm the chemistry of solutions of [Pd(NH₃)₂Cl₂] in aqueous NH₄Cl at various pH. In addition, potential sweep and step methods at rotating and stationary disc electrodes (both vitreous carbon and freshly plated palladium) are used to investigate palladium deposition from a standard electroplating bath, [Pd(NH₃)₂Cl₂] in NH₄Cl/NH₃ (pH 8.9). The relative importance of oxygen reduction, hydrogen absorption and hydrogen evolution as competing cathode reactions under various conditions is defined and the advantage of strong convection for high rate plating is demonstrated.     

[Ag2(aca)2]n and [Ag4(aca)4(NH3)2] (acaH = 9-anthracenecarboxylic acid): Synthesis,X-ray crystal structures,antimicrobial and anti-cancer activities

[Ag₂(9-aca)₂]_n and [Ag₄(9-aca)₄(NH₃)₂] (9-acaH = 9-anthracenecarboxylic acid) have been prepared and structurally characterized. [Ag₂(9-aca)₂]_n consists of polymeric ribbons of linked disilver(I) syn–syn bridged dicarboxylate units. [Ag₄(9-aca)₄(NH₃)₂] is tetrameric and centrosymmetric, with two syn–syn bridging carboxylates linked to the bimetallic Ag–Ag core and a further two syn–anti bridged carboxylate ligands in the equatorial plane, being coordinated to one Ag in the bimetallic core and to a second Ag, with the latter also bonded to an NH₃ ligand. In vitro studies show that both complexes are extremely cytotoxic against selected human fungal and bacterial pathogens, and each complex also greatly inhibits the growth of two mammalian cancer cell lines.     

配位离子液体［3（CH3CH2）4N+Cl-·（NH2）2CO］的合成及表征

采用尿素和氯化四乙基铵为原料，合成了一种新型的配位离子液体，并通过红外和X－射线粉末衍射对其结构进行了表征。结果表明，尿素和氯化四乙基铵发生反应，使得原来尿素羰基峰由1690.72cm－1转移到了1619.10cm－1。由X－射线粉末衍射图可以看出，在2θ = 30.37°处有新的衍射峰。通过差热－热重分析，配位离子液体在室温到250℃可以稳定存在，与其他有机溶剂相比具有良好的稳定性。     

Highly Active Catalyst from [PdCl2(NH2(CH2)12CH3)2] on NH4ZSM-5

A palladium catalyst highly active for the cyclohexene hydrogenation has been obtained by heterogenisation of [PdCl₂(NH₂(CH₂)₁₂CH₃)₂] on zeolite NH₄ZSM-5. TOF is more than twenty times higher than for the homogeneous catalyst or the activated carbon heterogenised complex. Changes in the electronic state of palladium have been observed by XPS analysis. Palladium reduction is produced upon heterogenisation on the NH₄ZSM-5 zeolite.     

An Alternative Synthesis of [Pd2Cl2(μ-dmpm)2]

A new, high yield synthesis of [Pd₂Cl₂(m̈-dmpm)₂] (dmpm = bis(dimethylphosphino)methane), which avoids the use of the ill-defined, polymeric substance [PdCl(CO)]_n as a starting material, is described. The procedure involves ligand metathesis of [Pd₂Cl₂(m̈-dppm)₂] (dppm = bis(diphenylphosphino) methane) with dmpm using a solvent in which both [Pd₂Cl₂(m̈-dppm)₂] and [Pd₂Cl₂(m̈-dmpm)2] are only sparingly soluble. Yields of > 98% are routinely obtained.     

Ferroelectric phase transition in [(CH3)3 NH]3 Sb2Cl9 (TMACA)

The ferroelectric first order phase transition at 367 K has been discovered in TMACA crystals, which is presumably related to a motion of trimethylammonium cations.     

An aluminoborate directed by [Zn(H2O)4]2 + complex: Synthesis,structure and properties

A novel 3D aluminoborate with [Zn(H₂O)₄]²⁺ cationic complexes as structure-directing agents (SDAs), namely, [Zn(H₂O)₄][Al(B₅O₁₀)]·0.5(H₂O) (1), has been solvothermally prepared and characterized by IR spectroscopy, UV–vis reflection spectroscopy, thermogravimetric (TG) analyses, powder and single crystal X-ray diffraction, respectively. The alternative linkage of AlO₄ tetrahedra and B₅O₁₀ units produces an open-framework aluminoborate with helical 6- and 8-membered ring (MR) channels, as well as large odd 11-MR channels. The [Zn(H₂O)₄]²⁺ templates, generated in situ from solvothermal conditions, are orderly located in the center of the 11-MR channels. The second-harmonic generation (SHG) measurement indicates that 1 exhibits about 0.5 times that of KDP standard (K₂HPO₄).     

Ultrasonic investigations of [(CH3)2NH2]5Cd3Cl11

The temperature dependences of ultrasound velocities along the crystallographic a, b and c axis in [(CH₃)₂NH₂]₅Cd₃Cl₁₁ were studied in the vicinity of phase transition at 178.5 K. The results obtained for the longitudinal and shear ultrasonic velocities confirmed clearly the existence of the second-order phase transition at this temperature and the quadratic relation between δV₄ and δV₆ and phase transition parameter was observed.     

A new binuclear Cr(III) citrate anion: Synthesis,characterization and crystal structure of [Cr(CO(NH2)2)6]2[Cr2(CO(NH2)2)2(C6H4O7)2]3

The new anion [Cr₂(CO(NH₂)₂)₂(C₆H₄O₇)₂]^2 − has been isolated in the complex [Cr(CO(NH₂)₂)₆]₂[Cr₂(CO(NH₂)₂)₂(C₆H₄O₇)₂]₃. The crystals of this complex were obtained by a one-pot synthetic method using 1:1 molar ratio of hexaureachromium(III) chloride and trisodium citrate in aqueous medium. It was characterized by elemental analysis, IR spectroscopy and single crystal X-ray diffraction analysis. The compound crystallizes in space group R‾3 of the trigonal system with three formula units in a cell of dimensions a = b = 24.7461(4) Å, c = 13.7204(3) Å and γ = 120°. The crystal structure comprises the columns consisting of [Cr(CO(NH₂)₂)₆]^3 + cations surrounded by a cylinder of complex anions, [Cr₂(CO(NH₂)₂)₂(C₆H₄O₇)₂]^2 − which are packed in a honeycomb-like manner. This supramolecular architecture is formed and stabilized by inter- and intramolecular NH⋯O hydrogen bonds.     

邻菲咯啉衍生物钌配合物的制备及性能研究

钌-邻菲咯啉配合物已经广泛应用于电化学、光化学领域,以羟基苯基并[4,5]-邻菲咯啉（Hpip）为配体,合成二氯化三羟基苯基并[4,5]-邻菲咯啉钌（Ru（Hpip）3Cl2）。应用红外、紫外和荧光光谱对产物进行表征,用循环伏安法考察其电化学行为,研究pH、氧对其荧光强度的影响。结果表明Ru（Hpip）3Cl2在玻碳电极上有准可逆的电化学行为,在溶液中其对氧的响应倍数（I0／I）高达11．9。     

Synthesis and crystal structures of two new inorganic–organic hybrid polyoxomolybdate complexes: [Himi]4[{Co(imi)2(H2O)2}Mo7O24] · 4H2O and [Zn(imi)4]2[(imi)2Mo8O26] · 6H2O

The two new inorganic–organic hybrid polyoxomolybdate complexes [Himi]₄[{Co(imi)₂(H₂O)₂}Mo₇O₂₄] · 4H₂O (1) and [Zn(imi)₄]₂[(imi)₂Mo₈O₂₆] · 6H₂O (2) (imi = imidazole) have been prepared by conventional aqueous solution synthesis. Compound 1 consists of heptamolybdate anions [Mo₇O₂₄]⁶⁻ covalently linked by [CoN₂O₄]²⁺ octahedra into one-dimensional zigzag-shaped chains. The zigzag-shaped chains are further linked together via the hydrogen-bonding interactions to form a 2D supramolecular framework. Compound 2 is build up of an imidazole-coordinated octamolybdate anion, two imidazole coordinating zinc cations and lattice water molecules to form a three-dimensional framework via complex hydrogen-bonding.     

Second-sphere Coordination of [Pt(bipy)(NH3)2]2+ by Dibenzo-crown Ethers. Solution Spectroscopic Studies and the Crystal and Molecular Structures of [Pt(bipy)(NH3)2.dibenzo-30-crown-10] [PF6]2.0.6 H2O and [Pt(bipy)(NH3)2.dibenzo-24-crown-8] [PF6]2

In addition to hydrogen bonding and Coulombic forces, charge transfer interactions stabilise the 1:1 adducts formed between [Pt(bipy)(NH₃)₂] ²⁺ and a series of dibenzo-3n-crown-n (n = 6–12) ethers as evidenced by ¹H NMR and UV-visible spectra in solution and by X-ray crystal structures (for n = 8 and 10) in the solid state. Mutual diamagnetic (ring current) shielding by the aromatic systems of host and guest results in dramatic upfield shifts of certain aromatic proton resonances on adduct formation, especially when n = 10 or 11. A broad charge-transfer absorption band at 350 nm attains its maximum intensity at n = 11 though stability constant measurements indicate optimum binding when n = 10. X-ray diffraction studies reveal that, when n = 8, only one of the crown ether benzo-rings interacts with the bipyridyl ligand in a charge-transfer sense. However, when n = 10, the macrocycle is sufficiently large and flexible to allow both benzo-rings to enter into stabilising interactions with the bipyridyl ligand such that the platinum complex is encapsulated by the host in a U-shaped cavity.     

利用氢氧化镁热分解氯化铵制氨气工艺的研究

对利用氢氧化镁热分解氯化铵制氨气反应体系进行了热力学计算分析,以反应温度、反应物的物质的量比、反应时间为变量,以固体产物中的含氮量、氯收率以及氨气收率等为评价指标,对氢氧化镁热分解氯化铵制氨气的工艺条件进行了研究。实验结果表明,在反应温度为375 ℃,氢氧化镁与氯化铵的物质的量比为1∶0.75,反应时间为50 min时,氯收率和氨气收率均可达到90%以上,同时氢氧化镁分解氯化铵能够直接生成碱式氯化镁,不需向反应器中通入水蒸气。     

A porous the-type metal-organic framework based on [Mn4Cl]7 + clusters for selective gas sorption

An anionic cage-type metal–organic framework, {(Me₂NH₂)₅[Mn₄Cl(BTB)₄(H₂O)₄](DMF)₂(EtOH)₇}_n (1, DMF = N,N-Dimethylformamide), has been successfully prepared by the reaction of MnCl₂ with trigonal planar 4,4′,4″-benzene-1,3,5-triyl-tri-benzoic acid (H₃BTB) ligand under solvothermal conditions. Its structure was characterized by single-crystal X-ray diffraction techniques, which reveal that it is constructed by cross-linking BTB^3 − ligands with the in situ-generated square-planar [Mn₄Cl]^7 + secondary building units. The free space of 1 is formed by packing of octahedral and cuboctahedral cages, and the overall framework exhibits a 2-fold interpenetrated the-type topology. N₂ adsorption isotherm at 77 K confirmed the permanent porosities of the activated 1 and the variable-temperature adsorption measurements of CO₂ and CH₄ revealed its high adsorption abilities of CO₂ over CH₄ at room temperature.     

Electrochemical investigations of copper etching by Cu(NH3)4Cl2 in ammoniacal solutions

Cyclic voltammetry has been employed to investigate the mechanism of copper etching in ammoniacal buffered solutions of cupric chloride. Experiments involving an increase in the solution copper content (up to 0.5 m) and in the thickness of the copper electrode have been used to obtain a better understanding of the copper oxidation. Whatever the Cu(ii) concentration, the reduction occurred in two one-electron stages leading successively to Cu(i) and Cu(0). The concentration of ammonia was an important parameter. Increasing the ratio of Cu : NH3 favoured the formation of transient solid compounds. The expected two-step oxidation of copper was observed only for thin layers of electroplated copper. The determination of the corrosion current in etching solutions suggests that copper oxidation involves the formation of solid cuprous compounds.     

A novel bismuth ion-bridged chainlike assembly from paradodecatungstate [H2W12O42]10− anions: (NH4)7[Bi(H2W12O42)] · 20H2O

A new polyoxotungstate (NH₄)₇[Bi(H₂W₁₂O₄₂)] ·  20H₂O has been synthesized in aqueous solution and characterized by elemental analysis, IR spectroscopy, TG analysis and single-crystal X-ray diffraction. The most interesting structural feature of 1 is that the paradodecatungstate [H₂W₁₂O₄₂]¹⁰⁻ anions are linked, for the first time, by the trivalent main group atom Bi^III which appeared commonly as a heteroatom in polyoxometalate chemistry, into a one-dimensional chainlike structure.     

Lanthanide molecular oxohydroxides: Synthesis and characterisation of [Y4(μ4-O)(μ-OEt)2(μ,η2-AAA)2(η2-AAA)3]2(μ3-OH)4(μ3-OEt)2 (HAAA = allylacetatoacetate)

The reaction between Y₅O(OPrⁱ)₁₃ and allylacetatoacetate or 2-(methacryloyloxy)ethyl acetatoacetate in 1:5 stoichiometry afforded octanuclear oxohydroxo species. Structural characterization was achieved for the allylacetatoacetate derivative homo and copolymerisation reactions with styrene were evaluated for doping of polystyrene. Hydoxo species, Y₄(OH)₂(AAA)₁₀, where also obtained by reacting Y[N(SiMe₃)]₃ and HAAA.