Synthesis and Characterization of a H+ Exchanged Zirconate

A new protonated oxide has been synthesized by ion exchange of lithium by proton in lithium metazirconate, Li₂ZrO₃. Easy and complete ion exchange has been achieved in acidic medium. Characterization of the protonated solid by means of X–ray powder diffraction and thermogravimetric analysis allow to propose the nominal formulation “H₂ZrO₃”. However vibrational spectroscopy suggests that a more appropriate formulation would be as an oxyhydroxide ZrO(OH)₂.     

Ferrocenecarboxylic anhydride: identification of a new polymorph

A new monoclinic polymorph of ferrocenecarboxylic anhydride, [Fe₂(C₅H₅)₂(C₁₂H₈O₃)], was obtained. Three molecules are present in the asymmetric unit, two of them being nearly identical (r.m.s. deviation = 0.11 Å), with the Fe atoms on the same side of the anhydride functional group. In the third molecule, the two Fe atoms are located at opposite sides of the functional group (ferrocene–ferrocene pseudo‐torsion angle = 146.2°), a very unsual feature in metallocene anhydrides. A network of weak intermolecular hydrogen bonds was also disclosed.     

Synthesis and characterisation of a new high pressure polymorph of Cu2WS4

In this communication we report the synthesis and structural characterisation of a new body centred polymorph of Cu2WS4 prepared using hydrothermal methods. I-Cu2WS4 crystallises in space group I42m with cell parameters a = b = 5.44427(8), c = 10.0687(2) A and has a new structure type containing layers of edge-sharing CuS4 and WS4 tetrahedra.     

Intercalation modification of Fe OCl and its application in dye wastewater treatment

The textile industry spreads globally with the challenges of its wastewater treatment,especially dyes,which are difficult to degrade.To improve coagulation-flocculation process in dye wastewater treatment,an intercalation process was employed to prepare a new efficient coagulant of lithium borohydride-iron oxychloride(LiBH_4_FeOCl) in this study.The layered crystal pristine iron oxychloride(FeOCl) material was prepared by chemical gas phase migration.LiBH4 was introduced into the layers of two dimensional(2 D) FeOCl nanosheets by a simple method of liquid phase insertion.The samples were characterized by a field emitting scanning electron microscopy(SEM),a rotating anode X-ray powder diffractometer(XRD),etc.The cationic dye was employed as the simulated pollutant.A coagulation and decolorization experimental device was built to study the coagulation performance of the new coagulant LiBH_4_FeOCl.It is found that the intercalation modified LiBH_4_FeOCl exhibits the characteristics of crystal structure,and the layered structure of FeOCl is preserved.LiBH_4_FeOCl,as an insoluble inorganic solid coagulant,performs well for dye pollutants of methyl red,basic yellow 1,methylene blue,rhodamine B,ethyl violet and Janus green B.The reaction rate is significantly 68% higher than the current commercial coagulants of Al_2(SO_4)_3.The mechanism analysis reveals that LiBH_4_FeOCl breaks and disperses rapidly in the water environment.Its negatively charged material particles can be electrostatically adsorbed with dye pollutant molecules through electrostatic action.The above collaborative actions of breaking,dispersion and electrostatic adsorption are the main coagulation mechanisms of LiBH_4_FeOCl.The solid inorganic coagulant of LiBH_4_FeOCl provides a competitive alternative for traditional inorganic salts and organic coagulants.     

离子交换树脂固载SnCl4：合成,表征和酯化反应

均相催化剂的固载化,由于具有独特属性,近年来发展很快.我们在用高分于材料固载路易斯酸的研究中,发现固载在离子交换树脂的路易斯酸催化性能非常稳定.本文将空气中强烈水解,且腐蚀性很强的四氯化锡与大孔苯乙烯系阳离子交换树脂反应,首次合成了离了交换树脂四氯化锡复合物(以下简写成压IER·SnCl_4),并对IER·SnCl_4的IR、UV光谱性质及在酯化反应中的催化性能进行了研究.结果表明IER·SnCl_4不仅活性高,而且在重复使用性能上表现了突出特点,显示了良好的应用前景.     

Comparative study of layered tetravalent metal phosphates containing various first-row divalent metals. Synthesis, crystalline structure

The transition metal forms of α-zirconium-. titanium-, and hafnium phosphates were prepared by ion exchange method. Their structure was investigated by X-ray powder diffraction (XRPD) method. It was found that the transition metal containing phosphates have the same layered structure as the pristine tetravalent metal phosphates, except for the increase of interlayer distance from 7.6 Å to ～9.5 Å. As a result of the incorporation of transition metals in the layers, the c-axis is increased from ～15 Å to ～20 Å (in the case of titanium phosphate to ～25 Å). All other parameters (a, b and β °) are practically unchanged.      

Synthesis and ion exchange behaviour of polyaniline Sn(IV) arsenophosphate: a polymeric inorganic ion exchanger

Incorporation of a polymer material into an inorganic ion exchanger provides a class of hybrid ion exchangers with a good ion exchange capacity, high stability, reproducibility and selectivity for heavy metals. Such a type of ion exchanger ‘polyaniline Sn(IV) arsenophosphate’ has been synthesized by mixing polyaniline into inorganic material. This material is characterized using X-ray, IR, TGA studies in addition to ion exchange capacity, pH-titration, elution and distribution behaviour. On the basis of distribution studies, the material has been found to be highly selective for Pb(II). Kinetic study of exchange for the metal ions has been performed and some physical parameters such as self diffusion coefficient D₀, energy E_a and entropy ΔS* of activation have been determined.     

Synthesis, structure and electronic structure of a new polymorph of CaGe2

Reported are the flux synthesis, the crystal structure determination, the properties and the band structure calculations of a new polymorph of CaGe₂, which crystallizes with the hexagonal space group P6₃mc (no. 186) with cell parameters of a=3.9966(9) and c=10.211(4) Å (Z=2; Pearson's code hP6). The structure can be viewed as puckered layers of three-bonded germanium atoms, , which are stacked along the direction of the c-axis in an ABAB-fashion. The germanium polyanionic layers are separated by the Ca cations. As such, this structure is closely related to the structure of the other CaGe₂ polymorph, which crystallizes with the rhombohedral CaSi₂ type in the R3¯m space group (No. 166), where the layers are arranged in an AA′BB′CC′-fashion, and are also interspaced by Ca²⁺ cations. LMTO calculations suggest that in spite of the formal closed-shell configuration for all atoms and the apparent adherence to the Zintl rules for electron counting, i.e., Ca²⁺[3b-Ge¹⁻]₂), the phase will be a poor metal due to a small Ca-3d-Ge-4p band overlap. Magnetic susceptibility measurements as a function of the temperature indicate that the new CaGe₂ polymorph exhibits weak, temperature independent, Pauli-paramagnetism.     

3D Starfish-Like FeOF on Graphene Sheets: Engineered Synthesis and Lithium Storage Performance

To address the problems associated with poor conductivity and large volume variation in practical applications as a conversion cathode, engineering of hierarchical nanostructured FeOF coupled with conductive decoration is highly desired, yet rarely reported. Herein, 3D starfish-like FeOF on reduced graphene oxide sheets (FeOF/rGO) is successfully prepared, for the first time, through a combination of solvothermal reaction, self-assembly, and thermal reduction. Integrating the structural features of the 3D hierarchical nanostructure, which favorably shorten the path for electron/ion transport and alleviate volumetric changes, with those of graphene wrapping, which can further enhance the electrical conductivity and maintain the structural stability of the electrode, the as-prepared FeOF/rGO composite exhibits a superior lithium-storage performance, including a high reversible capacity (424.5 mA h⁻¹ g⁻¹ at 50 mA g⁻¹), excellent stability (0.016 % capacity decay per cycle during 180 cycles), and remarkable rate capability (275.8 mA h⁻¹ g⁻¹ at 2000 mA g⁻¹).     

Retention characteristics of a new butylimidazolium-based stationary phase. Part II: anion exchange and partitioning

A surface-confined ionic liquid (SCIL) and a commercial quaternary amine silica-based stationary phase were characterized employing the linear solvation energy relationship (LSER) method in binary methanol/water mobile phases. The retention properties of the stationary phases were evaluated in terms of intermolecular interactions between 28 test solutes and the stationary phases. The comparison reveals a difference in the hydrophobic and hydrogen bond acceptance interaction properties between the two phases. The anion exchange retention mechanism of the SCIL phase was demonstrated using nucleotides. The utility of the SCIL phase in predicting logk _IL/water values by chromatographic methods is also discussed.     

Synthesis and Characterization of Europium‐exchanged Titanate Nanoporous Phosphors

Eu_x(NH₄)_2‐2xTi₃O₇ nanoporous phosphor was prepared by ion exchange method. (NH₄)₂Ti₃O₇ nanotubes were employed as the host structure by treating H₂Ti₃O₇ with NH₄OH solution and the activator, Eu²⁺, was introduced into the host via ion exchange. This is an easy and feasible way to prepare a phosphor. The synthesized samples were characterized using TEM, XRD, N₂ adsorption‐desorption isotherm, TPR, and fluorescence spectrophotometer. Experimental results showed that a portion of Eu²⁺ ions was oxidized into Eu³⁺ ions during ion exchange, resulting in the present phosphor with blue‐emitting and red‐emitting. Moreover, the tubular structure of Eu_x(NH₄)_2‐2xTi₃O₇ was distorted as Eu²⁺ was placed into the host structure. This distortion is attributed to the electrostatic interaction between Eu²⁺ and the electric field of the host structure.     

Synthesis of highly ordered cubic zeolite A and its ion-exchange behavior

Well-ordered cubic zeolites 4A were synthesised using sol–gel process in the presence of different silica and aluminum sources. The aluminum and silica sources determined whether or not zeolites were formed at precise silica/alumina mole ratio. Zeolites were formed only when the aluminum source was sodium aluminate, the silica source was fumed silica, colloidal silica or sodium metasilicate. Our findings indicated that the type of zeolite invariably obtained was 4A and SEM images indicated that the produced zeolites are cubic shaped crystals with planar surfaces and well-defined edges and sharp crystals. In turn, synthesis parameters are seen to have a significant effect in maximizing heavy metals uptake (for example Cu²⁺, Cr³⁺, Cd²⁺ and Ni²⁺) by synthesized zeolites. Zeolite 4A gave better heavy metal uptakes than amorphous or non-zeolite crystalline materials. This was attributed to higher ion-exchange capacity and higher BET specific surface area 445 m²/g and pore volume 0.141 cm³/g. The latter attribute possibly translates to greater accessibility of ion-exchange sites and selectivity towards metal type by this zeolite followed the sequence: Cu²⁺ > Cr³⁺ ≥ Cd²⁺ > Ni²⁺.     

Synthesis and characterization of a new ethynyl-bridged C60 derivative bearing a diketopyrrolopyrrole moiety

A new soluble C₆₀ derivative bearing a diketopyrrolopyrrole (DPP) moiety has been synthesized by ethynylation reaction. Characterization by UV-visible spectrophotometry and cyclic voltammetry has been performed in order to study the influence of the DPP moiety on electronic and optical properties of the fullerene. Moreover, DFT calculations have been conducted on the derivative and its precursor in order to correlate the orbital geometry with experimental data.     

Synthesis and quadratic molecular hyperpolarizabilities of two new chiral boronates: Computational and experimental study

A monomeric boronate and an oxobridged chiral dimer were obtained by reaction of the ligand derived from 4-diethylaminosalicylaldehyde with (R)-(−)-phenylglycinol, and phenyl boronic acid or boric acid. The compounds were fully characterized by spectroscopic techniques (¹H, ¹³C, ¹¹B NMR, elemental analyses, IR and masses spectrometry); and their molecular hyperpolarizabilities were investigated by the electric field induced second harmonic (EFISH) technique and semi-empirical calculations. The experimental quadratic hyperpolarizability which is equal to 9.8 × 10⁻³⁰ cm⁵ esu⁻¹ at 1.064 μm for the monomeric derivative rises to 19.5 × 10⁻³⁰ cm⁵ esu⁻¹ in the dimeric specie.     

Synthesis of 3,6-dioxa-Δ-4-trifluoromethyl perfluorooctyl trifluoromethyl sulfonimide: bis[(perfluoroalkyl)sulfonyl] superacid monomer and polymer

A new type of ion exchange polymer, bis[(perfluoroalkyl)sulfonyl]imide ionomers (PFSI), were developed by the copolymerization of sodium 3,6-dioxa-Δ⁷-4-trifluoromethyl perfluorooctyl trifluoromethyl sulfonimide with tetrafluoroethylene (TFE) using an aqueous redox initiation system in an emulsion type polymerization. These polymers have been prepared in various equivalent weights and processed into functional membranes. The new ionomers exhibit excellent chemical and thermal stability. The materials have high potential for electrochemical applications especially as solid polymer electrolytes (SPE) in proton exchange membrane (PEM) fuel cells.     

Synthesis and Characterization of Layered Double Hydroxides Containing Optically Active Transition Metal Ion

The acetate intercalated layered double hydroxides of Zn and Mn, have been synthesized by chimie douce method. The materials were characterized by XRD, TGA, CHN, IR, XPS, SEM-EDX and UV-visible spectroscopy. The photoluminescence properties was also studied. The optical properties of layered hydroxides are active transition metal ion dependent, particularly d¹⁻¹⁰ system plays an important role. Simultaneously the role of host – guest orientation has been considered the basis of photoluminescence. Acetate ion can be exchanged with iodide and sulphate ions. The decomposed product resulted the pure phase Mn doped zinc oxide are also reported.     

Synthesis and stability of new spiroaminoborate esters

New spiroaminoborate esters derived from 1,1-diphenylprolinol, ephedrine, and dihydroquinine with different alkoxy substituents were prepared as stable crystalline compounds and characterized by spectroscopical analysis and specific rotation. The structure of the spiroborate 4 derived from 1,1-diphenylprolinol and dicyclohexyl-1,1′-diol was confirmed by X-ray analysis.     

Ion chromatography for the separation of heparin and structurally related glycoaminoglycans: A review

The global crisis resulting from adulterated heparin in late 2007 and early 2008 revived the importance of analytical techniques for the purity analysis of heparin products. The utilization of ion chromatography techniques for the separation, detection, and structural determination of heparin and structurally related glycoaminoglycans, including their corresponding oligosaccharides, has become increasingly important. This review summarizes the primary HPLC approaches, particularly strong anion exchange, weak ion exchange, and reversed‐phase ion‐pair, used for heparin purity analysis as well as structural characterization. Strong anion exchange HPLC has been studied most extensively and currently offers the best separation of crude heparin and heparin‐like compounds. Weak anion exchange HPLC has been shown to provide shorter analysis times with lower salt concentrations in the mobile phase but is not as widely developed for the separation of all glycoaminoglycans of interest. Reversed‐phase ion‐pair HPLC offers fast and effective separations of oligosaccharides derived from glycoaminoglycans that can be coupled to mass spectrometry for structural analysis. However, this method generally does not provide sufficient retention of intact glycoaminoglycans.     

空气条件下高温固相合成层状LiMnO2及其离子交换的影响规律

在空气中高温固相反应合成了层次单斜结构前驱体NaMnO2，在不同条件下进行离子交换反应，得到LiMnO2。用X射线衍射法表征了前驱体及交换产物的晶体结构，用电感耦合等离子体光谱进行元素含量分析，用扫描电镜测定晶体的形貌。结果表明，离子交换反应条件对反应速率和产物的晶体结构与组成有重要影响。