The synthesis and vibrational spectra of the antimony(V)fluoride-fluorosulfates SbF3(SO3F)2, SbF4(SO3F) and Sb2F9(SO3F)

The synthesis of the title compounds by a variety of routes is described. These routes involve the oxidation of antimony(III)fluoride by bis(fluorosulfuryl)peroxide and the use of non-statistical ligand redistribution reactions. Complex formation with ClO₂SO₃F leads to ClO₂[SbF_n(SO₃F)_6-n], with n=3 or 4. Polarized Raman data and low temperature infrared data are reported. All antimony(V)fluoride-fluorosulfates are found to have fluorosulfate bridges with SbF₃(SO₃F)₂ and SbF₄(SO₃F) being polymers. Ionic formulations for the ClO⁺₂ complexes are again based on vibrational spectra.     

Vibrational study of hydrogen bonding and structural disorder in Na2H(SO4)2, K3H(SO4)2 and (NH4)3H(SO4)2 crystals

Infrared and Raman spectra on Na₃H(SO₄)₂, K₃ H(SO₄)₂ and (NH₄)₃ H(SO₄)₂ crystals have been investigated at 300 and 100 K in the 4000 to 30 cm⁻¹ region. An assignment of bands in terms of OH group frequencies and more or less distorted tetrahedra of ammonium and sulphate ions is given. The crystallographic and spectroscopic symmetry and/or dissymetry of OHO hydrogen bonds linking sulphate ions into dimers is discussed using OH group frequencies and the splitting of the v₁ (SO₄) Raman bands as criteria. In the particular case of (NH₄)₃H(SO₄)₁ compound containing several solid phases it can be shown that the room temperature phase (II) is strongly disordered, principally because of an orientational disorder of ammonium ions, and that a progressive ordering takes place with temperature lowering.     

Investigation of phase equilibria in the systems K2SO4Sc2(SO4)3, Rb2SO4Sc2(SO4)3 and Cs2SO4Sc2(SO4)3

Phase diagrams of the systems K₂SO₄Sc₂(SO₄)₃, Rb₂SO ₄Sc₂(SO₄)₃ and Cs₂SO₄ Sc₂(SO₄)₃ have been investigated by X-ray diffraction phase analysis and differential thermal analysis techniques. A salient feature of all the systems is the formation of M₃Sc(SO₄)₃, which melt incongruently, and MSc(SO₄)₂, which on heating decompose in the solid state.     

The reaction of (SO2)2 and (CO2)2 with Ba

The reactions of (CO₂)₂ and (SO₂)₂ with Ba have been investigated using a crossed beam arrangement and the laser-induced fluorescence technique. Internal energy in the BaO product was probed in order to study differences between monomeric and dimeric reactions. The reaction cross section for the dimers of CO₂ was found to be between four and eightfold larger than that of the monomers. This can be explained by the change in the reaction mechanism due to the positive electron affinity of the dimers versus the negative electron affinity of the monomers. The product BaO from the dimeric reactions is much colder rotationally than in the monomeric case. This phenomenon can be explained based on the kinematics.     

Temperature behavior of the protonic conductor K4LiH3(SO4)4

The results of the X-ray structural study for the K₄LiH₃(SO₄)₄ single crystal are presented at a wide temperature range. The thermal expansion of the crystal using the X-ray dilatometry and the capacitance dilatometry from 8 to 500 K was carried out. The crystal structures data collection, solution and refinement at 125, 295, 443 and 480 K were performed. The K₄LiH₃(SO₄)₄ crystal has tetragonal symmetry with the P4₁ space group (Z=4) at room temperature as well as at the considered temperature range. The existence of a low-temperature, para-ferroelastic phase transition at about 120 K is excluded. The layered structure of the crystal reflects a cleavage plane parallel to (001) and an anisotropy of the protonic conductivity. The superionic high-temperature phase transition at T_S=425 K is isostructural. Nevertheless, taking into account an increase of the SO₄ tetrahedra libration above T_S, a mechanism of the Grotthus type could be applied for the proton transport explanation.     

Infrared spectra of KNaSO4 and K3Na(SO4)2

The infrared spectra, transmittance and polarized reflectance, of KNaSO₄ and K₃Na(SO₄)₂ are reported. Group theoretical analysis was carried out and a vibrational assignment proposed on basis of C_3v and D_3d symmetries. Factor group and site effects are discussed.     

Determination of sulfur contents of SO3, S2O3 and S based on the electrocatalytic interaction with homogeneous mediator tris(2,2'-bipyridyl)Ru(II)

A sensitive voltammetric method has been developed for the determination of total or single species of sulfur anions containing sulfide, sulfite and thiosulfate. The method is based on the catalytic effect of tris(2,2'-bipyridyl)Ruthenium(II) (Ru(bpy)₂^+ 2) as a homogeneous mediator on the oxidation of those anions at the surface of a glassy carbon electrode. A reversible redox couple of Ru(II)/Ru(III) were observed as a solute in aqueous solution. Cyclic voltammetry study showed that the catalytic current of the system depends on the concentration of the anions. Optimum pH values for voltammetric determination of sulfite, thiosulfate and sulfide has been found to be 5.6, 10.0 and 10.0, respectively. Under the optimized conditions the calibration curves have been obtained linear in the concentration ranges of 0.8–500.0, 0.4–1000.0 and 0.5–5000.0 µmol L^− 1 of SO₃²⁻, S₂O₃²⁻ and S²⁻, respectively. The detection limits have been calculated to be 0.40, 0.17 and 0.33 µmol L^− 1 for SO₃²⁻, S₂O₃²⁻ and S²⁻, respectively. The diffusion coefficients of sulfite and thiosulfate have been estimated using chronoamperometry. The chronoamperometric method also has been used to determine the catalytic rate constant for catalytic reaction of the Ru(bpy)₂^+ 2 with sulfite and thiosulfate. Finally the proposed method has been used for the determination of total sulfur contents in real samples of water and wastewater. Moreover the sulfite content in sugar and sulfur dioxide in air has been determined with satisfactory results.     

Fe2(SO4)3/γ-Al2O3固体超强酸的Mössbauer谱研究

采用浸渍法制备了一系列Fe2(SO4)3/ γ-Al2O3型固体超强酸样品,用Moessbauer谱和XRD研究了不同温度处理对样品中铁组分的存在状态及稳定性的影响。结果表明,随Fe2(SO4)3含量的变化,铁组分可以在γ-Al2O3表面以单层分散和无定形形式存在;当温度≥600℃时,无定形状态的Fe2(SO4)3又生成晶态的Fe2(SO4)3,而形成的晶态Fe2(SO4)3即使在700℃时也不分解。     

Raman spectroscopic study of K3H(SO4)2 (phases I and II) single crystals

A Raman study of K₃H(SO₄)₂ as a function of temperature reveals that this compound undergoes a phase transition at T_c = 483 K prior to the decomposition at 508 K.     

The phase diagram of the system La2(SO4)3Ag2SO4

The phase diagram of the system La₂(SO₄)₃Ag₂SO₄ was studied by DTA, XRD, SEM, and optical methods. One double salt is formed at 67 mole% La₂(SO₄)₃ and this melts incongruently at 876±6°C. A eutectic is formed at 8 mole% La₂(SO₄)₃ and at a temperature of 618±3°C. Suppression of decomposition was effected by the sealed tube method, but some reference is made to experiments conducted with a flowing atmosphere of SO₃, SO₂ and O₂.     

TiCl(OCH3)(SO3Cl)(OSO2F)-chloro(chlorosulfato)(fluorosulfato)-methoxytitanium(IV) - asymmetric titanium(IV) compound

A stable titanium(IV) compound with four different kinds of ligands, TiCl(OCH₃)(SO₃Cl)? (SO₃F), results when TiCl₂(OCH₃)(SO₃F) is refluxed with HSO₃Cl using CH₂Cl₂ as the solvent. It is an off-white solid and decomposes around 125°C. The powder X-ray diffraction studies of the title compound will be discussed along with other physical and chemical properties.     

Vibrational study of the unusual phase sequence in Tl3Cr(SO4)3: A compound containing [Cr(SO43−3]∞ columns

The polarized Raman spectra of small single crystals of Tl₃Cr(SO₄)₃ have been recorded using the Raman microprobe technique in the temperature range 295–660 K. The behavior of the external modes is analyzed on polycrystalline samples with conventional Raman spectrometer from 100 K to the decompositon temperature 660 K. Analysis of the spectra, in connection with dielectric measurements and X-ray data show that Tl₃Cr(SO₄)₃ undergoes the following space group phase sequence

$\text{P2}{}_1\text{c}\text{→}\text{340}\text{K}\text{R}\text{3}\text{→}\text{450}\text{K}\text{R3c}\text{→}\text{630}\text{K}\text{R}\text{3}\text{c}$

in accordance with the point group relationship

$\text{2}\text{m}\text{→}\text{3}\text{→3m→}\text{3}\text{m}$

     

The thermal decomposition,IR spectrum and crystal structure of ammonium manganese(II) tris(hydrogenselenite), NH4Mn(HSeO3)3

The compound NH₄Mn(HSeO₃)₃ has been prepared and its IR spectrum and thermal behaviour have been investigated. It crystallizes in the monoc     

A new synthesis of acetamido phenols promoted by Ce(SO4)2

A new method for the synthesis of acetamido phenols by a one-pot, three-component Ritter type reaction in moderate to good yields is described. Both electron donating and electron releasing substitution on aromatic rings are tolerated.     

原位产生的SO42-配位的二维无机钴配合物K2[Co3(OH)2(SO4)3(H2O)2]的水热合成及晶体结构

相同的水热反应条件下4-氨基-二(2-吡啶基)-1，2，4-三氮唑(abpt)、KSCN与钴盐(CoCl₂·6H₂O)反应合成了2种新的钴配合物:零维的单核配合物[CoSCN(abpt)] (1α)和二维的无机层状配合物K₂[Co₃(OH)₂(SO₄)₃(H₂O)₂] (1β)，并通过元素分析和红外光谱对其进行了表征。配合物1α的晶体属于单斜晶系，P2₁/c空间群。配合物1β晶体属于正交晶系，Cmc2₁空间群。在配合物1α中，abpt和SCN^-配体都参与配位与Co(Ⅱ)离子形成了2个不同的单核单元，这些单核单元又通过S原子和N原子之间的氢键作用连成了三维超分子结构;在配合物1β中，abpt配体没有参与配位，而SCN^-配体则被氧化成了SO₄^2-离子并与Co(Ⅱ)离子配位形成了二维配位层状结构，相邻层之间进一步通过氢键作用形成了沿c轴方向有孔道的三维超分子网络，这些孔道里面填充着反离子K+。     

A kinetics study of the reaction of SO2 with CH3O2

The reaction ot CH₃O₂ with SO₂ has been studied using the flash photolysis/ultraviolet absorption technique. In contrast to previous measurements, no reaction could be detected over the temperature range 298–423 K. An upper limit of 5 × 10^?17 cm³ molecule^?1 s^?1 has been determined for the reaction rate constant.     

Structural and vibrational studies of Li[Kx(NH4)1−x]SO4 and Li2KNH4(SO4)2 mixed crystals

Mixed crystals of Li[K_x(NH₄)_1−x]SO₄ have been obtained by evaporation from aqueous solution at 313 K using different molar ratios of mixtures of LiKSO₄ and LiNH₄SO₄. The crystals were characterized by Raman scattering and single-crystal and powder X-ray diffraction. Two types of compound were obtained: Li[K_x(NH₄)_1−x]SO₄ with x?0.94 and Li₂KNH₄(SO₄)₂. Different phases of Li[K_x(NH₄)_1−x]SO₄ were yielded according to the molar ratio used in the preparation. The first phase is isostructural to the room-temperature phase of LiKSO₄. The second phase is the enantiomorph of the first, which is not observed in pure LiKSO₄, and the last is a disordered phase, which was also observed in LiKSO₄, and can be assumed as a mixture of domains of two preceding phases. In the second type of compound with formula Li₂KNH₄(SO₄)₂, the room-temperature phase is hexagonal, symmetry space group P6₃ with cell-volume nine times that of LiKSO₄. In this phase, some cavities are occupied by K⁺ ions only, and others are occupied by either K⁺ or NH₄⁺ at random. Thermal analyses of both types of compounds were performed by DSC, ATD, TG and powder X-ray diffraction. The phase transition temperatures for Li[K_x(NH₄)_1−x]SO₄x?0.94 were affected by the random presence of the ammonium ion in this disordered system. The high-temperature phase of Li₂KNH₄(SO₄)₂ is also hexagonal, space group P6₃/mmc with the cell a-parameter double that of LiKSO₄. The phase transition is at 471.9 K.