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Abstract
The extraction of iodine and bromine under various conditions from their saturated aqueous solutions by CCl4, C6H6 and o-xylene has been studied. The data obtained from the experiments carried out at various temperatures, for H2O(I2)−CCl4 and H2O(I2)−C6H6 systems, exhibit an Arrhenius behaviour. The overall activation energy calculated for the extraction in the H2O(I2)−CCl4 system, 650±50 cal·mol−1 is lower than that of H2O(I2)−C6H6, 3600±300 cal·mol−1. The use of the solubility parameter for the interpretation of the data in the extraction of iodine is investigated. The data obtained in multiple extractions are treated by using the analogy between extraction and radioactive decay. The half number of extraction for each system is determined. The complex curves obtained in the H2O(I2)−CCl4 and H2O(I2) −Br2)−CCl4 systems are resolved into two components.
Six adducts of the tctrakis(8-hydroxyquinolinato) complex of thorium(IV) with 8-hydroxyquinoline, pyridine, urea, dimethylsulphoxide, dimethylformamide and 1,10-phenanthroline were prepared and characterized, the infrared bands for the room-temperature forms are given and their particular thermal properties are reported. The thermal analyses were performed mostly in the presence of air, but in some cases an argon atmosphere was used for comparison. The adducts were lost from the principal complex at temperatures varying between 110 and 290°. Intermediate oxygenated complexes were formed in each case at about 400°. The thermal data suggest the standardization of a procedure for the formation of Th(C9H6NO)4.
Abstract
This work describes the synthesis, IR and UV-Vis spectroscopic characterization as well the thermal behavior of the [NiCl2(HIPz)4]⋅C3H6O (1), [Ni(H2O)2(HIPz)4](NO3)2 (2), [Ni(NCS)2(HIPz)4] (3) and [Ni(N3)2(HIPz)4] (4) (HIPz=4-iodopyrazole) pyrazolyl complexes. TG experiments reveal that the compounds 1–4 undergo thermal decomposition in three or four mass loss steps yielding NiO as final residue, which was identified by X-ray powder diffraction.
Abstract
Thorium isotopes in seawater are determined by means of adsorption of the Xylenol Orange /XO: H6A/ complex onto XAD-2 resin at pH=3 and the XO concentration of 10–5M, and subsequent purification using an anion-exchange resin, and finally with alpha-spectrometry. The dissolved232Th concentration in the western North Pacific surface water is found to range from 0.8 to 1.2 
Bq 
–1. The adsorbed species of the Th-XO complex under the experimental conditions has a composition of Th/H2A/2 according to the mass balance analysis.
Abstract
Solutions of I2 in C6H6 were irradiated with X-rays, in the energy range from 4.6 to 8.0 keV, thus including the characteristic X-ray of Cr /5.412 keV/, just above the L-absorption edge for iodine /5.118 keV/. Yield of iodobenzene and the organic yield of iodine were investigated as a function of I2 concentration and of the absorbed radiation dose. It is found that the formation of iodobenzene, which was the only product detected, is due to the Auger activation of iodine atoms, and not to the radiolytic decomposition of benzene molecules from direct interaction of X-rays.
The thermal decompositions of dicitratoborates M1[B(C6H6O7)2]·nH2O (n=0–2, M1=Rb, K, Li, NH4) and M11[B(C6H6O7)2]2·8H2O (M11=Co, Ni, Mn, Cu, Zn, Cd) were investigated by means of TG, DTA and DTG methods. It was found that these thermal decompositions involve three successive stages: dehydration, the endothermal decomposition of the ligand, and oxidation of the residual organic component. The volatile products of decomposition in each stage were detected by means of gas chromatography. The method of TG-curve transformation into the curvedm/d T vs.m, wherem is the loss of weight at each moment of time, was used for a more detailed study of dehydration. The optimal conditions for TG-curve modification were found.
Abstract
Thermal treatment of SiO2-aerogel in inert atmosphere, in contrary to oxidizing atmosphere, yields a series of gas products with great range of mole masses (12–154 g mol–1) and every product has specific way of evolving. These substances are represented by CO, CO2, CH4, CH3OH, C2H6, C2H4 and aromates. Part of evolving products, which are formed during catalytic condensation, is trapped under the surface and after carbonisation it causes opacity of surface layer of aerogel.
Abstract
Abstract
The hydrolytic products of manganese carbide Mn7C3 are hydrogen and a number of paraffins of the series CH4, C2H6, C3H8, etc., whose concentrations characteristically decrease with increasing number of carbon atoms in the hydrocarbon molecule. A radioanalytical method applied after Mn7C3 hydrolysis by tritium, oxide has revealed that an analogous series of olefins in trace concentrations is formed as well. It has been confirmed that the sum of the concentrations of hydrocarbons higher than C4 corresponds to the trend of the series. A stoichiometric and structurally consistent radical mechanism of Mn7C3 hydrolysis is proposed as derived from the composition of the hydrolytic products. The initial components of the radical reactions could be CH 2 ¨ and CH 3 · radicals. The statisical and combinatorial aspects of the mechanism are also discussed.
Abstract
1×105M–1s–1, as it has been calculated. Long-lived intermediates have not been observed in C6H6.