The reduction of oxygen in molten lithium carbonate

Oxygen reduction on immersed gold electrodes has been studied in Li₂CO₃ melt under steady-state conditions and by the potential-sweep method. Reaction order measurements have established that the species being reduced is not molecular oxygen, but the peroxide ion. The latter is in chemical equilibrium with molecular oxygen and oxide ions. The rate-determining step is the primary charge transfer

where (O^?) is a transient species. The exchange current densities and activation energies have been determined. Under conditions where O₂^2? diffusion is not limiting (e.g. meniscus electrodes) the rate of neutralization of oxide by CO₂ at the electrode surface is probably rate-determining.     

Creatinine complexes of zinc,cadmium and mercury

Zinc, cadmium and mercury(II) complexes of creatinine of the composition M(Creat)₂X₂ (X = Cl, Br or I) are prepared. The complexes are characterized by analytical and spectral methods. The increase in cyclic NH stretching frequency in the case of complexes (3350 cm^?1) from that of the free ligand (3300 cm^?1) suggested that secondary nitrogen is involved in coordination. The shift in the resonances of cyclic NH proton in the ¹H NMR and carbonyl and imine carbons in ¹³C NMR when compared to the ligand indicated that cyclic nitrogen coordinates. Conductivity measurements in N, N-dimethylformamide suggested that the complexes are non-electrolytes. Thermal decomposition behaviour of the complexes is also discussed.     

Extraction of zinc, cadmium and mercury salicylates

A systematic study of the solvent extraction of Zn, Cd and Hg salicylates is reported. Optimum conditions for extraction and separation of Zn, Cd and Hg are evaluated from a critical study of pH, sodium salicylate concentration, mesityl oxide concentration, period of equilibration, and effect of diverse ions. A separation scheme is described and results are reported for analysis of synthetic mixtures and commercial samples.     

Molten lithium sulphate-sodium sulphate—potassium sulphate eutectic. The reactions of six vanadium compounds

The solubilities and thermal stability of six vanadium compounds of oxidation states V, IV and III [i.e., V₂O₅, NaVO₄, Na₃VO₄, VOSO₄, VO₂ and KV(SO₄)₂] have been studied in the ternary eutectic (78 mole % Li₂SO₄, 8.5 mole % Na₂SO₄, 13.5 mole % K₂SO₄) and the products of their reactions with basic, acidic, oxidising and reducing reagents have been identified.     

The infrared spectra of the dimethyl complexes of zinc,cadmium and mercury

The infrared spectra of the dimethyl complexes of zinc, cadmium and mercury, isolated in argon matrices, have been measured. Earlier assignments of the spectrum of the zinc compound appear to have included a band due to a methane impurity. A study of the RAIR spectrum of a thin film of ZnMe₂ on a copper surface has revealed that the molecules in the film are strongly orientated and the additional information thus obtained has made it possible to suggest some reassignment of the spectra of all three compounds.     

1-Phenylvinyl compounds of lithium,mercury, and thallium

Summary Methods are described for the preparation of 1-phenylvinyl compounds of mercury and thallium from the salts of these metals and 1-phenylvinyllithium. Some chemical properties of these compounds were investigated.     

Interaction of pectin substances with copper,mercury, zinc,and cadmium salts

The interaction of the sage, mint, apple, and ginseng pectins, isolated from tissue culture wastes and purified with copper, mercury, zinc, and cadmium salts, has been studied by the amperometric method with two metal indicator electrodes. The optimum conditions of titration have been determined: pH 3.5–5.0; concentration of pectin substances 5·10^–5-1·10^–3 g/ml of solution. It has been established by graphical and mathematical methods that the interaction is accompanied by the formation of compounds with a ratio of the carboxy groups of pectins to the metal cation of two. The IR spectra of sage pectin and of copper and mercury pectinates are given.M. V. Frunze, Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 171–175, March–April, 1988.     

Homoleptic cadmium and mercury compounds of stanna-closo-dodecaborate

The reaction of stanna- closo-dodecaborate [SnB 11H 11] (2-) (1) with CdBr 2 gave the tetrahedrally coordinated compound [Cd(SnB 11H 11) 4] (6-)(2). The same coordination mode can be found in [Hg(SnB 11H 11) 4] (6-) (3), which was obtained by reaction of stannaborate with Hg 2Cl2. Both compounds were characterized by single crystal X-ray analysis and heteronuclear NMR techniques.     

Molten potassium thiocyanate: The reactions of some compounds of iron,cobalt, nickel,copper and zinc

The electronic spectra of four transition metal cations stable in molten potassium thiocyanate [Fe(II), Co(II), Ni(II) and Cu(I)] are reported together with their reactions and those of three unstable cations [Fe(III), Co(III) and Cu(II)] with a variety of anions including cyanide, cyanate and sulphide. A novel reduction of zinc(II) sulphate is also reported.     

Extractive separation of trace amounts of mercury, cadmium and zinc

A simple solvent extraction procedure is reported for the sequential separation of mercury(II), cadmium(II) and zinc(II). Mercury is separated first using 1,3-diphenyl-2-thiourea in chloroform at an overall acidity of 0.3M HCl. Then cadmium separated using the same reagent at pH 10 into dichloromethane. The zinc which is remaining in the aqueous phase is then quantitatively extracted into toluene-cyclohexanol mixture using 2-mercaptobenzoxazole. Suitable stripping solutions have been proposed for the re-extraction of these metal ions for their subsequent estimations. The method has been made highly selective by the use of appropriate masking agents and has been applied in conjunction with estimation procedures for the determination of these metal ions in city waste incineration ash (CRM 176), mercuric chloride (A. R. grade) and in magnesium alloy samples.     

The synthesis of some mercury organic compounds

Summary We have synthesized diallylmercury, di-o-anisyl mercury, di-m-flurophenyl mercury, di-m- and di-p-chlorophenyl mercury, di-o-carbomethoxyphenyl mercury, and m-fluorophenyl mercuric bromide.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 924–925, May, 1965 Original article submitted August 13, 1964     

Thermal expansion of the group IIb liquid metals zinc,cadmium and mercury

The volumetric thermal expansions of the group IIb liquid metals zinc, cadmium and mercury were measured using the γ densitometry technique. The data for zinc and cadmium were obtained approximately 200 K above the melting point. Measurements for mercury were made up to 140 K above ambient temperature. The study was conducted to investigate the reported low volumetric thermal expansion of the group IIb liquid metals relative to a large number of other liquid phase elements. The volumetric thermal expansion coefficients in the melt were determined to be 1.41 × 10⁻⁴ K⁻¹ (± 1.5%) for zinc, 1.43 × 10⁻⁴ K⁻¹ (±0.6%) for cadmium and 1.79 × 10⁻⁴ K⁻¹ (± 0.3%) for mercury. These results are in agreement with recent measurements performed using other techniques.     

Molten lithium carbonate—sodium carbonate—potassium carbonate eutectic: The reaction of ten main group acidic oxides and oxyanions

The reactions of ten main group acidic oxides and oxyanions with molten alkali metal carbonate eutectics have been studied by thermogravimetry. Products have been identified by IR and Raman spectroscopy and stoichiometries suggested for the several reactions as oxide is progressively incorporated. Ultimately the tetrahedral ortho-oxyanion was formed except with the less acidic oxides (As₂O₃, Sb₂O₃, SiO₂). Sulphite was partially oxidised by the carbon dioxide atmosphere to sulphate.     

Molten lithium nitrate-potassium nitrate eutectic: some reactions of copper(II) and of metallic silver

Copper(II) nitrate trihydrate has been successfully dehydrated in lithium nitrate-potassium nitrate eutectic at 140°C. At 300°C it commenced reaction as a Lux-Flood acid precipitating copper(II) oxide. With potassium iodide it reacted at 140°C to form copper(I) iodide and iodine but at 180°C the insoluble product was a mixture of copper(I) iodide and copper(II) oxide. With powdered silver a violent reaction occurred at 160°C, yielding silver(I) cations, nitrogen dioxide and copper(II) oxide. The stoichiometries of these reactions have been established and some reaction pathways suggested. Metallic silver was found to react to a much larger extent with a Lux-Flood acid (pyrosulphate) in solution than with nitrogen dioxide giving support to the nitryl cation as the acidic species in nitrate melts.     

Molten lithium carbonate—sodium carbonate—potassium carbonate eutectic: The reaction of six first row transition metal cations

The reactions of manganese(II), iron(II), iron(III), cobalt(II), nickel(II) and copper(II) chlorides with the molten alkali metal carbonate eutectic have been studied by thermogravimetry. The insoluble products (binary or ternary metal oxides) have been identified by X-ray diffraction and reaction stoichiometries are suggested. Nickel(II) solutions were sufficiently stable for electronic spectroscopy and indicated, as did thermogravimetry, that addition of potassium chloride did not cause significant formation of chloro complexes.     

Solubilities of zinc oxide and cadmium oxide in KCl-LiCl eutectic melts

ZnO solubility (pP = 4.77 ± 0.1) and CdO solubility (pP = 1.46 ± 0.1) in KCl-LiCl melts at 700°C are determined using the sequential additions method with the potentiometric control of the equilibrium oxide ion concentration. Cadmium oxide is a strong base; it fully dissociates in unsaturated solutions. Zinc oxide is a weak base (pK _ZnO = 2.89 ± 0.15). As the acidic properties of an ionic solvent strengthen with a fixed anionic composition, the solubilities of the oxides increase in correlation with their basicity index; the surface energy at the interface between the solid oxide and ionic melt decreases in association.     

Thermochemical study of the reaction of Lewis bases with zinc,cadmium and mercury halides in solution

The reaction of HgI₂, CdI₂ and ZnX₂ (X = Cl, Br, I) with heterocyclic bases and triphenylphosphine in acetonitrile solution has been studied calorimetrically. Hgl₂ forms 3-coordinate adducts with pyridine or 4-methylpyridine and both 3- and 4-coordinate adducts with PPh₃; enthalpies of formation of HgN and HgP bonds are similar. Enthalpies of reaction of CdI₂ and ZnX₂ with bases are less than those of HgI₂, probably because solvent displacement occurs. The relative stabilities of adducts in solution is Zn > Cd > Hg with N-bases and Hg ≫ Cd > Zn with PPh₃; this reversal of order is mainly attributable to entropy effects.