Transfer of Liquid Cathode Components to the Gas Phase and Their Effect on the Parameters of the Atmospheric Pressure DC Discharge

The transfer of solvent and components of dissolved substances from aqueous solutions to the gas phase under the action of atmospheric pressure air glow discharge was experimentally studied. solutions of NaCl, KCl, CuCl₂, MgCl₂, CaCl₂, SrCl₂, BaCl₂, NaNO₃, KNO₃, Ba(NO₃)₂, Na₂SO₄, K₂SO₄, CuSO₄ with concentrations of 0.1–0.5 mol/L were used as the cathodes of DC discharge at a current of 10–70 mA. The influence of the solution composition on cathode voltage drop and the electric field strength in plasma has been shown. Plasma emission spectra showed the appearance of metal atoms in the plasma requires threshold discharge current or threshold power input to the liquid cathode by ion bombardment. The threshold power values depend on the mass of hydrated cations and their concentration in solution. The efficiency of the transfer processes was characterized by transfer coefficients—the number of particles transferred from the liquid to the gas phase per one ion bombarding the cathode. Dependences of the transfer coefficients on the power dissipated in the cathode region and on the hydration energy of the cations were obtained. Experimental data on the rate of condensate accumulation in the special trap were used to estimate the concentrations of water molecules in the plasma.     

Binuclear copper complexes with non-steroidal anti-inflammatory drugs as studied by electrospray ionization mass spectrometry

The solutions containing one of the copper salts (CuCl₂, Cu(ClO₄)₂, Cu(NO₃)₂, and CuSO₄) and one of the non-steroidal anti-inflammatory drugs (NSAIDs, ibuprofen, ketoprofen or naproxen) were analyzed by electrospray ionization mass spectrometry. Three of the salts, namely CuCl₂, Cu(ClO₄)₂ and Cu(NO₃)₂, yielded binuclear complexes of drug:metal stoichiometry 1:2. Existence of the complexes of such stoichiometry has not been earlier observed. For copper(II) chloride the complexes (ions of the type [M-HCOOH+Cu₂Cl]⁺ and [M+Cu₂Cl]⁺, M stands for the drug molecule) were formed in the gas phase. When copper(II) perchlorate or copper(II) nitrate was used, the observed binuclear copper complexes (ions of the type [M-H+Cu₂(ClO₄)₂+CH₃OH]⁺, [M-H+Cu₂(ClO₄)₂]⁺ and [M-H+Cu₂(NO₃)₂+CH₃OH]⁺, [M-H+Cu₂(NO₃)₂]⁺) were observed at low cone voltage, thus these complexes must have already existed in the solution analysed. Therefore, such complexes may also exist under physiological conditions.      

Thermodynamic properties and solution equilibria of aqueous bivalent transition metal nitrates and magnesium nitrate

Osmotic coefficients for Mn(NO₃)₂, Co(NO₃)₂, Ni(NO₃)₂, Cu(NO₃)₂, Zn(NO₃)₂, and Mg(NO₃)₂ in aqueous solution have been determined by the isopiestic method at 25°C, and activity coefficients have been derived. The results agree with the literature data for Zn(NO₃)₂, while they are significantly different for Co(NO₃)₂, Cu(NO₃)₂, and Mg(NO₃)₂, and those for Mn(NO₃)₂ and Ni(NO₃)₂ are new. The concentration dependence of the osmotic coefficients for the bivalent metal nitrates is similar to that for the trifluoroacetates, while it differs from those for the other salts of the same series of metals. The results are discussed in terms of the inner-sphere and outer-sphere association of ions, auxiliary information being derived from the concentration effects in the visible spectra of the coloured metal nitrates.     

纳米银的电解质效应

向2种不同电性的纳米银溶胶中分别加入KCl、KBr、KI、KNO3、Mg(NO3)2、Al(NO3)3、K2CO3、K2SO4、KOH和HNO3电解质溶液,利用透射电子显微镜、紫外-可见分光光度计等研究电解质对纳米银的显微结构和光谱学性质的影响。结果表明,不同电解质离子在纳米银胶体表面吸附程度以及导致纳米银胶体聚集和生长程度不同,从而对纳米银胶体的分散状态和表面电势产生不同影响。这种影响的结果导致其对相同电性纳米银粒子和不同电性纳米银粒子的显微结构和光谱学性质影响不同。     

Dissolution enthalpy of glycine in aqueous solutions of bivalent metal electrolytes

Measurement of the dissolution enthalpies of glycine in aqueous solutions of MgCl₂, CaCl₂, SrCl₂, BaCl₂, Mg(NO₃)₂ and Ca(NO₃)₂ at 298.15 K have been undertaken. The enthalpic heterogeneous interaction coefficients of the glycine zwitterion with the dissociated electrolyte have been calculated using the standard enthalpies of solution of amino acid in water and in aqueous solution of electrolytes. The effect of the ion type and of the structure of glycine on the magnitude of the enthalpic interaction coefficients are discussed.     

The study of the speciation of uranyl–sulphate complexes by UV–Vis absorption spectra decomposition

Uranyl–sulphate complexes are the predominant U(VI) species present in acid solutions resulting either from underground uranium ore leaching or from the remediation of leaching sites. Thus, the study of U(VI) speciation in these solutions is of practical significance. The spectra of UO₂(NO₃)₂ + Na₂SO₄ solutions of different Φ _S = [SO₄²⁻]/[U(VI)] ratio at pH = 2 were recorded for this purpose. As the presence of uranyl-nitrate complexes should be expected under these experimental conditions, the spectra of UO₂(NO₃)₂ + NaNO₃ solutions with different Φ _N = [NO₃⁻]/[U(VI)] ratio at pH = 2 were also measured. The effects of Φ _S and Φ _N ratios value were most pronounced in wavelength interval 380–500 nm. Therefore, these parts of experimental overall spectra were used for deconvolution into the spectra of individual species by the method proposed. It enabled to calculate stability constants of anticipated species at zero ionic strength. The Specific Ion Interaction Theory (SIT) was used for this purpose. Stability constants of UO₂SO₄, UO₂(SO₄)₂²⁻, UO₂NO₃ ⁺ and UO₂(NO₃)₂ coincided well with published data, but those for UO₂(SO₄)₃⁴⁻ and UO₂(NO₃)₃⁻ were significantly lower.     

Vibrational spectra and structure of trinitromethane

The vibrational spectrum of trinitromethane was interpreted in terms of the additive interatomic interaction model on the basis of experimental infrared and Raman spectra of HC(NO₂)₃, DC(NO₂)₃, HC(¹⁵NO₂)₃ and normal coordinate analysis. The frequency assignment results were used in discussing its structure. It was shown that the symmetry of trinitromethane is below C₃ in the liquid state.     

Solubility of the Copper(II) Salt–Sodium Formate–Water Systems at 25°C

Solubilities in the CuSO₄ (CuCl₂, Cu(NO₃)₂)–NaHCOO–H₂O systems are studied at 25°C using the isothermal sections method. Crystallization regions of copper(II) formate mono- and dihydrate are elucidated. It is proved that copper(II) formate can be synthesized in CuAn₂ + 2NaHCOO ? Cu(HCOO)₂ + 2NaAn–H₂O quaternary reciprocal systems using the conversion method.     

Volumetric and Viscometric Studies on Some Inorganic Electrolytes in Water and in Water-SDS Solution Systems

The apparent molal volumes (φ _v ) of NaCl, NaNO₃, NH₄Cl, CuCl₂, CuSO₄, CoSO₄ and MgSO₄ in water and in water-SDS (Sodium dodecyl sulphate) solutions were determined from density measurements at 308.15, 313.15 and 323.15 K respectively. The limiting apparent molal volume at infinite dilution φ ^o _v which is practically equal to the partial molal volume V ^o ₂) of these electrolytes were found to be higher in water-SDS solution systems than those in water solutions. Viscosity coefficients (A and B) for these systems were also determined by Jones-Dole equation. All these electrolytes, except NH₄Cl exhibit structure making behaviour in water and in water-SDS solutions. Ammonium chloride showed structure breaking properties in water and in 0.01 molar water-SDS solutions. In 0.1 molar SDS solution, it showed structure making behaviour at the temperature range studied. The properties of these electrolytes in water and in water-SDS solution systems have been discussed in terms of the charge, size and hydrogen bonding effect.     

Photoconductivity of poly(vinyl alcohol) films containing Cu2+ complexes

Photoconductivity has been measured in well-dried poly(vinyl alcohol) (PVAl) films containing Cu²⁺ complexes prepared by treatment with Cu(NO₃)₂, CuSO₄, CuCl₂, and CuBr₂. When the ratio [Cu²⁺]/[MU] ([MU] denoting the concentration of PVAl monomer residues) is greater than 0.015, illumination at the charge-transfer (UV) band produces a strong photocurrent in PVAl-CuCl₂ and PVAl-CuBr₂, but not in PVAl-Cu(NO₃)₂ or PVAl-CuSO₄. Optical absorption spectra suggest that two halide ions enter the first coordination sphere in the cis configuration. The temperature dependence of ESR indicates the existence of antiferromagnetic superexchange interaction via intervening halide ions. Hence, there exists a network structure of the PVAl-CuCl₂ or PVAl-CuBr₂ complex. The dependence of the photocurrent on the polarity of the illuminated electrode shows that the majority of carriers are holes. Holes in the network structure produced by charge transfer from halogen to Cu²⁺ ions are concluded to be responsible for the photoconduction.     

Effect of parameters of square-wave pulsating current on copper electrodeposition in the hydrogen co-deposition range

Copper electrodeposition processes in the hydrogen co-deposition range by the pulsating current (PC) regime were examined by the determination of the average current efficiency of hydrogen evolution and by the scanning electron microscopic (SEM) analysis of the morphology of the formed deposits. The two sets of the square-wave PC of the same pause to pulse ratios, but with different duration of deposition pulses and pauses were analyzed. The one set of square-wave PC was with the constant pause duration and different deposition pulses. In the other set, the deposition pulse was constant while the pause duration was varied. The obtained results were compared with those obtained by electrodeposition at the constant overpotential from solutions of different CuSO₄ and H₂SO₄ concentrations. It was found that the effect of the increasing deposition pulse was equivalent to the decreasing CuSO₄ concentration, while the effect of the decreasing pause duration was equivalent to the increasing H₂SO₄ concentration. It is shown that it is possible to achieve a substitution of more solutions of different CuSO₄ and H₂SO₄ concentartions by the use of the only one solution if the appropriate PC parameters were applied, what can be of high technological significance.     

Controlled synthesis of CuO nanostructures by a simple solution route

A simple solution route has been developed to prepare nanostructured CuO with Cu(NO₃)₂·3H₂O and NaOH as starting materials. CuO nanoribbons or nanorods and their assemblies into hierarchical structures have been synthesized, respectively, by controlling the molar ratio of NaOH to Cu(NO₃)₂, reaction temperature and the concentration of the starting NaOH solution. Experiments demonstrate that the molar ratio of NaOH to Cu(NO₃)₂ is an important parameter which may decide whether CuO exists in nanoribbons (nanorods) or assemblies into hierarchical structures. Whether Cu(NO₃)₂ is dissolved in ethanol or water also influences the formation of monodispersed CuO nanoribbons (nanorods). The growth mechanism of these nanostructures is discussed. The products were characterized by X-ray diffraction, field-emission scanning electron microscopy and transmission electron microscopy (HRTEM) and their optical absorption spectra were also studied.     

Photoelectron spectra of quaternary salts in solution

The ionisation energies, measured by He(I) photoelectron spectroscopy, are reported for I^?, Cl^?, Br^?, CNS^? and NO^?₂ in adiponitrile solution. These energies give a straight line when plotted against the energies of the electron transfer to solvent absorption bands of the ions in acetonitrile solution. The intercept gives the electron affinity of the solvent; for acetonitrile, assumed to be spectroscopically equivalent to adiponitrile, the electron affinity is found to be 1.85 eV; for water it is 1.65 eV. The energies of electron transfers not observable in the UV absorption spectrum of NO^?₂ solutions are estimated from the photoelectron spectra.     

Photochemistry,vol. 8 : Senior Reporter D. Bryce-Smith,Specialist Periodical Report,Chemical Society,London, 1977, pp. xix + 644, price £37.00

Raman spectra have been obtained for Hg(CN)₂, Hg(NO₃)₂, and Hg(CNS)₂ in both liquid NH₃ and ND₃ at ambient temperature. The spectra indicate the presence of the species Hg[(CN)₂(NH₃)₂] and [Hg(NH₃)₄]²⁺ in the mercury(II) cyanide and nitrate solutions respectively. The mercury(II) thiocyanate solutions, however, appear to contain solvated Hg(CNS)₂ and[HG(NH₃)₄]²⁺ cations.     

Structural Effects and Microheterogeneity in Concentrated Solutions and Their Role in the Formation of Cadmium Chloride Complexes

The proton relaxation rate and Raman spectra in the regions of vibrations of the Cd-Cl, Cd-OH₂ groups and bending vibrations eta₄ of nitrate ions in the systems CdAn₂-NaCl-H₂O (An = Cl^-, ClO₄ ^-, NO₃ ^-) were measured. In the range of subeutectic concentrations of cadmium salts all possible forms of chloride complexes of cadmium are formed. In the posteutectic region the formation of complexes is structurally induced; it depends on the nature of dominating cybotactic groups and is limited to the formation of only low-coordinate forms. The mechanisms of the formation of chloride complexes in perchlorate and nitrate systems were proposed. It was concluded that, in contrast to the chloride system, the nitrate and perchlorate systems in the presence of sodium chloride are characterized by structural microheterogeneity. The distinctions in the nature of the microheterogeneity and its effect on the complex formation were considered. The solubility polytherm and Raman spectra of the system Cd(NO₃)₂-NaCl-H₂O with a high content of the both salts were measured. The causes of abnormally high mutual solubility of nitrate salts in multicomponent solutions containing salts that crystallize in the hydrated and anhydrous forms were suggested.     

The Analysis of Chiniofon by Fluorometric Titration

Abstract

A rapid method for the determination of 7-iodo-8-quinolinol in Chiniofon has been suggested. Samples of the material are dissolved in a pH 9 buffer containing Mg(NO₃)₂ and aliquots of this solution are titrated with CuSO₄ solution in the dark, under an ultraviolet lamp. The disappearance of fluorescence indicates the end-point of the reaction.     

Vibrational spectroscopic studies of uranyl complexes in aqueous and non-aqueous solutions

Vibrational spectra have been obtained for aqueous solution of uranyl-perchlorates, -fluorides, -chlorides, -acetates and -sulphates over a range of solution composition with added anions. We have prepared [Buⁿ₄N][UO₂Cl₄], [Me₄N][UO₂Cl₄], [Prⁿ₄N][[UO₂(NO₃)₃], [Buⁿ₄N][UO₂(NO₃)₃], with the expectation that the large cation would give a better approximation to vibrational frequencies of the free anion and would allow measurements in non-coordinating solvents. As the perchlorate is not coordinated to [UO₂]²⁺ in aqueous solution the expected structure is a solvated cation [UO₂(OH₂)₅]²⁺ with characteristic infrared 962.5, 253 and 160 cm⁻¹ and Raman 874 and 198 cm⁻¹ bands. The formation of weak, solvated [UO₂X]⁺ complexes (X=F, Cl) has been established with frequencies at 908, 827, 254, 380 cm⁻¹ and 956, 871, 254 and 222 cm⁻¹ for [UO₂F]⁺ and [UO₂Cl]⁺, respectively. Bidentate NO₃ coordination has been established for solid and dissolved (in CH₂Cl₂) [R₄N][UO₂(NO₃)₃] (R=Prⁿ, Buⁿ). Aqueous solutions of UO₂(NO₃)₂ and Cs[UO₂(NO₃)₃] show no clear evidence that bidentate or monodentate nitrate is present. Both unidentate and bidentate linkage of acetate-uranyl were established for acetate complexes in aqueous solutions. For the uranyl sulphate system, monodentate sulphate coordination is the major mode at low SO₄:U ratios, and even at a ratio of 3:1 there is very little free sulphate.     

Preparation and characterization of finely dispersed pigment particles

Dispersions of uniform colloidal pigments were produced by precipitating solutions of disodium salts of 2-amino, 5-methyl benzosulfonic acid (4B-dye), and 2-amino, 4-chloro, 5-methyl benzosulfonic acid (2B-dye) with Ca(NO₃)₂, SrCl₂, or Ca(NO₃)₂/SrCl₂ solutions in the absence and in the presence of additives (surfactants and alcohols). The latter affected the morphology of the particles, but had a negligible effect on their crystal structures. However, drying the Ca-4B pigment resulted in the change of the crystal phase and morphology. As a rule, the Sr-4B pigment was spheroidal, while Ca-4B, Ca-2B, and Ca/Sr-4B consisted of elongated particles.     

Photosynthesis-inhibiting effects of 2-benzylsulphanylbenzimidazoles in spinach chloroplasts

Inhibition of photosynthetic electron transport (PET) in spinach chloroplasts by nineteen 2-benzylsulphanylbenzimidazoles (BZA) was studied. BZA were found to inhibit photosynthetic electron transport (PET) and for their inhibitory efficiency, electronic properties of the R substituent on the benzyl moiety are decisive. The PET inhibiting activity of the studied BZA expressed as IC50 varied in the range from 28.5 ??M (R = 3,5-(CF₃)₂) to 394.5 ??M (R = 2,4-(NO₂)₂). For compounds with R = H, 4-CH₃, 3-CH₃, 3-OCH₃, 4-F, 3-F, 4-Cl, 3-Cl, 2-Cl, 4-Br, 3-Br, 3,4-F₂, 3,4-Cl₂, 3-CF₃, 3,5-(CF₃)₂ linear increase of the inhibitory activity with the increasing value of the substituent??s ?? constant up to 0.86 was observed. Further increase of the ?? constant resulted in a sharp activity decrease of the corresponding compounds (R = 2-F-6-Cl, 2-NO₂, 3,5-(NO₂)₂, 2,4-(NO₂)₂). Using EPR spectroscopy and an artificial electron donor diphenyl carbazide it was found that the site of BZA action in the photosynthetic apparatus is situated on the donor side of PS 2, prior to the Z^·/D^· intermediate.     

Stereoisomerism of dihalodiaryl(acetylacetonato)-antimony(V) compounds

A series of dihalodiaryl(acetylacetonato)antimony(V) compounds, (p-Y-C₆H₄)₂SbX₂Acac (X=F, Cl, Br; Y=NO₂, Cl, H, CH₃, CH₃O), were prepared. All of these compounds are monomeric and exist in solution as a mixture of two isomers both with chelated hexacoordinate configurations. From the temperature- and solvent-dependent PMR spectra of these compounds, it is concluded that the two isomers are in equilibrium in solution. The assignments of the PMR signals to the isomers were made by considering the effects of solvent and the substituents X and Y on the spectra.