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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.

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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.

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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 14 undergo thermal decomposition in three or four mass loss steps yielding NiO as final residue, which was identified by X-ray powder diffraction.

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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.

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Journal of Thermal Analysis and Calorimetry
Authors:
E. M. Schwartz
,
I. M. Vitola
,
G. S. Sergeiyeva
,
G. O. Piloyan
, and
O. V. Drozdova

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.

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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.

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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.

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Abstract  

In the present work
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\dot OH$$ \end{document}
as well as HRO. radicals were generated in the photochemical interaction of 1,2-benzanthracene with
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\dot OH$$ \end{document}
radicals were trapped by C6H6. The main reaction of HRO. radicals is hydrogen abstraction from the hydroperoxide group of HROOH. Although OH radicals are less selective, the hydrogen abstraction is the main process during their interaction with aromatics in contrast to reactions in aqueous solutions, where addition to the benzene ring is the rate-determining process in CCl4:
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\begin{array}{*{20}c} {k_{\dot OH + HRO\underline {OH} } /k_{\dot OH + \underline {HR} OOH} = 2.5 \pm 0.5 and} \\ {k_{\dot OH + C_6 H_6 } /k_{\dot OH + \underline {HROOH} } = /1.2 \pm 0.15/xlo^{ - 2} .} \\ \end{array}$$ \end{document}
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Abstract  

The complexes of yttrium and lanthanide with 1,1-cyclobutanedicarboxylic acid of the formula: Ln2(C6H6O4)3nH2O, where n=4 for Y, Pr–Tm, n=5 for Yb,Lu, n=7 for La, Ce have been studied. The solid complexes have colours typical of Ln3+ ions. During heating in air they lose water molecules and then decompose to the oxides, directly (Y, Ce, Tm, Yb) or with intermediate formation. The thermal decomposition is connected with released water (313–353 K), carbon dioxide, hydrocarbons(538–598 K) and carbon oxide for Ho and Lu. When heated in nitrogen they dehydrate to form anhydrous salt and next decompose to the mixture of carbon and oxides of respective metals. IR spectra of the prepared complexes suggest that the carboxylate groups are bidentate chelating.

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Journal of Thermal Analysis and Calorimetry
Authors:
J. P. Bastide
,
K. Ezzemouri
,
J. M. Létoffé
,
P. Claudy
, and
A. Bouamrane

The thermal behaviour of complexes [Li+-EC](AlH4) withEC=12-C-4, 15-C-5, DC 18-C-6 (cis-anti-cis andcis-syn-cis isomers) was investigated by Differential Scanning Calorimetry (DSC). These complexes were prepared as solids from benzene solutions. Pure EC and several solvated species [Li+-EC](AlH4)·nC6H6 (EC=15-C-5, DC 18-C-6syn) were also studied. DSC has revealed various phenomena. Solid-solid transitions were observed before melting for [Li+-EC](AlH4) withEC=12-C-4 and 15-C-5. They are probably explained by small molecular modifications strongly dependent on the thermal history of the sample. A glass-transition was found for the pure crown-ether DC 18-C-6anti, the complex [Li+-EC](A1H4) withEC=DC-18-C-6anti and the two solvates mentioned above.

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